DIFFERENCES IN DISTANCE COVERED BETWEEN TREADMILL AND OUTDOOR TRACK RUNNING AND WALKING.

ABSTRACT

The purpose of this study is to establish the differences in distance covered between treadmill and outdoor track walking and running in 30 participants (18 Male, 12 Females, aged 30.3 ± 9.9 years, weight 68 ± 16.33 kg and height 166.5 ±8.64 cm) which were divided into two groups (walking and running). Every subject was apparently healthy and filled up a PAR-Q and consent form. Each participant performed their walk or run both on treadmill and Outdoor track. A treadmill, distance measuring device and data analysis were used in this study. Data was collected and compared between the two modes of running and walking. Results shows there are significant difference (p>.05) between treadmill and outdoor track running. Walking on the treadmill has a mean distance covered of 923±32 meters per km walk and average difference of 77 meters per km walk, running on the treadmill have a mean distance covered of 987±22 meters per km run and average difference of 12 meters per km run.

INTRODUCTION

1.1 Introduction

Treadmills are widely used in sports institutes, health & fitness facilities and even in homes as a way to replicate running outdoors. Treadmill running is a convenient and effective method of training when outdoor weather is in appropriate to train in (e.g. too hot or cold, raining, snowing). This machine is also used for health & fitness evaluation (e.g. VO2 max, stress test) as speed and gradient ran by the subject can be controlled and maintained.
However, for an elite athlete, it is important to maximize training intensities and volume per training session in order to optimize performance gains. Effectiveness of treadmill running is questionable relative to outdoor running. Intensities may differ widely within these two modes of running at a given speed, gradient and duration. Elemental factors such as wind resistance, running surface (e.g. sandy), temperature and humidity may also play a significant role in the variance of intensities between treadmill and outdoor running. A study by (Pugh, L., 1970) showed that wind resistance influences energy cost when running. He estimated that wind resistance increases energy cost during running by 8% at 21.5 km/h (5km race pace) and 16% at 36km/h (100 meters in 10 seconds).
Thus the age old question of whether treadmill running fully replicates outdoor running in terms of intensity and distance covered remains. While it has been established that there is a difference in the former, with research being done between treadmill and outdoor running in relation to VO2Max by Meyer et al., (2003) and RPE (rate of perceived exertion) by Ceci et al., (1991) where the results show significantly different levels of RPE, heart rate (HR), blood lactate, and velocity. However, up to date there were no literature found on the latter.

1.2 Objective

The purpose of the paper is to clarify 1) difference in distance between treadmill and outdoor running is present and 2) study the difference in recorded distances between low and high speeds of treadmill running. This is from biomechanical understanding of running gait, focusing on the double swing phase during running. As the swing phase of running is approximately 70% of the whole gait cycle, it is reasonable to assume that the treadmill belt may be moving faster than that of the runner. To confirm this both walking and running on treadmill procedures are done as approximately 60% is spent on the stance phase during walking. Results will then be discussed and recommendations are made for people and athletes who utilize treadmills as a training tool.

1.3 Hypothesis

The hypothesis for this study is 1) There is a difference in distance between treadmill and outdoor track running and 2) The difference in distance is smaller at treadmill speed of 5km/h which is walking compared to 11km/h which is running.

1.4 Operational Definitions

A portable measuring device (RS400SD, Polar Finland) is used to measure distance ran both on the track and treadmill. The reliability and validity is reported to be 0.97-0.99 (Polar)

LITERATURE REVIEW

2.1 Literature Review

There have been numerous studies done between the differences of treadmill and track activities whether it is sprinting, running, jogging or walking. There have also been research done in specific areas of treadmill and track running which includes biomechanical (stride length, stride frequency and shock attenuation) and to biochemical factors (energy expenditure, blood lactate and Vo2max). (Hall et al., 2004) studied the differences between energy expenditure of walking vs. running 1600m by using 12 male and 12 female subjects while walking (4.8 km/hr) and running (9.6 km/hr) 1600m on the treadmill and subgroup of 7 males and 10 females also performed the 1600m run/walk on the track where calorimetry was measured on all subjects. Their findings showed that running utilized significantly more energy for 1600m than walking in both genders (treadmill: running 481 ± 20, walking 340 ± 19 kJ; track: running 480 ± 23, walking 430 ± 14 kJ, P<0.01), r =" 0.99)"> 0.99). They concluded that at 1% grade for 15 and 16.5 km/h, the VO2 during road running was not significantly different from that at 1% or 2% grade but was significantly greater than 0% grade and significantly less than 3% grade. At 18km/h, the VO2 for road running fell between the VO2 value for 1% and 2% grade treadmill running but was not significantly different from any of the treadmill grade conditions. Thus equality of the energetic cost of treadmill and outdoor running with the use of a 1% treadmill grade over duration of 5 min at velocities between 10.5 and 18 km/h most closely reflects the outdoor running.
One study (Crouter et al., 2001) compared physiological responses using a open-circuit spirometer during incremental treadmill exercise and free range running where the result showed that the observed peak values for blood lactate (14.4 6 3.3 vs. 11.7 6 3.0 mmol•L-1) were significantly (P, 0.05) different. It was concluded that there is a fundamental lack of free range exercise effect or whether it is related to mode specificity still needs to be determined. The authors also suggested that higher VO2 values may be achieved by free range/outdoor running.
Apart from this, when concerning treadmill test, study from Bundle et. al, (2003) regarding high speed running performance, provides a new approach to assessment and prediction. These authors recruited seven competitive runners of different event specialties and tested them on treadmill rung and on ground level surfaces where the maximum speed supported by anaerobic power was determined from the fastest speed that subjects could attain for a burst of eight steps and the maximum speed supported by aerobic power, velocity at maximal oxygen uptake. This was determined from a progressive, discontinuous treadmill test to failure. Results showed that measured values of the maximum speeds supported by anaerobic and aerobic power, in conjunction with an exponential constant, enable to predict the speeds of all-out treadmill trials to within an average of 2.5% and track trials to within 3.4%. An algorithm using this exponent and only two of the all-out treadmill runs to predict the remaining treadmill trials was nearly as accurate (average 3.7%). It is concluded that both techniques provide accurate predictions of high-speed running performance in trained runners and offers a performance assessment alternative to existing tests of anaerobic power and capacity (e.g. Wingate test).
Findings by Nummela et. al, (2005) on developing a track version of the maximal anaerobic running test (usually done on treadmills) by determining the blood lactate versus running velocity curve for both the treadmill and track protocols where maximal running velocity (Vmax) where the velocities associated with blood lactate concentrations and the peak blood lactate concentrations were determined. The result showed that the maximal running velocity was significantly higher on the track (27 ±2.8 km/h) than on the treadmill (25.6 ± 2.7 km/h), and sprint runners had significantly higher Vmax and peak blood lactate concentrations than distance runners.

In sprint runners, the velocity of the seasonal best 400-m run correlated positively with Vmax in the treadmill and track protocols. In distance runners, a positive correlation was observed between the velocity of the 1000-m time-trial and Vmax in the treadmill and track protocols. It is concluded that the track version of the maximal anaerobic running test is a valid means of measuring different determinants of sprint running performance.

In conclusion, many studies have been conducted but there is a lack of data. Hence, in order further to maximize running performance (Kubukeli et al., 2002; Laursen et al., 2002; Riley et al., 2008) on the treadmill and to fully replicate outdoor running, coaches and athletes must be able to maximize training intensities and volume performed per training session. Along with other factors such as running economy and biomechanics of gait (White et al., 1998; Mercer et al., 2003) being maximized and utilized fully in order to gain physiological adaptation and benefits due to optimize training session thus increase in performance in treadmill running.

METHODOLOGY

3.1 Methodology

Participants were instructed to perform two modes of running/walking on a treadmill and over ground (track). A distance and speed tracking device (Polar RS400SD, Polar Finland) was utilized on both protocols to establish distance. This validity and reliability of this device is reported to be 0.97 to 0.99 (Polar) . Distances was recorded and compared between actual (track and treadmill) and device.

3.2 Subjects

30 subjects from a health and fitness facility (18 male and 12 female, age 30.3 ± 9.9 years, height 166.5 ±8.64 cm and weight 68 ± 16.33 kg) volunteered to participate in this study. They were individuals who have experience running both outdoors and on a treadmill. These individuals are perceived to be appropriate in order to save time (do not require familiarization to treadmill running). The participants were all apparently healthy individuals and have completed a PAR-Q and consent form to terminate any health risks that this testing may pose.

3.3 Apparatus

A Polar running computer was used in this study as a distance tracking device (Polar RS400SD). Participants were allowed to wear their regular exercise gear with the exception of compulsory running shoes. The treadmill by TechnoGym (RUN 700) was utilized for the treadmill run test. The treadmills used were calibrated by the gym facility technician. A personal computer (PC) was also used to run the Software (Polar Pro-Trainer) provided along with the running computer to obtain the most accurate distance as it provides the distance by 3 decimal points (e.g. 4.xxx KM). A PAR-Q (pre exercise questionnaire) and a consent form was also utilized.

3.4 Procedure

The device is first calibrated on a 400m rubberized track with a 1200m (3 laps) run as the minimum recommended calibration distance is 1000m. The group of 30 participants were divided into two for the walking (5.0 km/h) and running (11.0 km/h) procedures (outdoor and treadmill). As for the walk/runs by this experiment’s participants, they were instructed to run 1100m on the treadmill procedure and track procedure. Data recorded was for 1KM after the first 100m to initiate the device. Participants were ordered to make a complete stop at the end of each 1000m run as to ensure no further distance recording took place before ending the trial run recording on the RS400. The actual distance walked and ran outdoors and on the treadmill is then recorded with the running computer. A comparison between actual distance on the track and distance recorded is compared. The same is done on the treadmill procedure with the distance shown as the ‘actual’ distance on the console. Data is then interpreted with the T-Test to identify significance of the result.

RESULTS

4.1 Descriptive statistics

30 subjects (18 males and 12 females) participated in this study where the mean age 30.3 ± 9.9 years, height 166.5 ±8.64 cm, and weight 68 ± 16.33 kg.
4.2 Results comparison between distances covered in Treadmill and Track groups.
Results shows the distance of combination of both Treadmill and Track groups (Table 4.2.1) shows that per km run/walk, the average distance covered on the treadmill is 955±43 meters in distance covered per 1000 meters (1km). Conversely, the track groups show exact amount of distance covered which is 1km. Shortest distance covered per km is by treadmill group is 854 meters and the highest distance covered per km run/walk is 1025 meters which has a range of 171.

Results of the independent sample T-test shows that there is a significant difference in distance covered between treadmill and outdoor track (t= 5.74, df=58, p<0.05). t=" 2.19," df=" 28," p="0.037)" t="9.224," df="28," t=" 5.74," df =" 58,">

DISCUSSION

5.1 Discussion

In this present study, the question can be answered whether there is difference in distance between treadmill and outdoor running and the difference in distances between low and high speeds of treadmill running are possible. By using the portable measuring device (RS400SD, Polar Finland) to measure distance ran both on the track and treadmill were (r = .99) of the device is reported (Polar International) using 30 subjects (15 subjects in running group and 15 subjects in walking group) for both treadmill and outdoor track distance measurement for 1km. Based on the results obtained, the mean difference in distance between treadmill and outdoor track is for per km run/walk is 45±43 meters (p<.05). Thus for practical implication, a trained athlete would exercise on the treadmill might consider to increase the distance run/walk on the treadmill by 45±43meters per km. This is because the difference is significant enough to effect performance (Gormley et.al 2008), (Kubukeli et. al, 2002), (Laursen et. al, 2002), (Mujika et. al 2000) as which is important to maximize training intensities and volume per training session in order to optimize performance increase in which relates to one of the aspect which is the distance ran. For an example, if an athlete would run for 10km on the treadmill then the difference would be greater as such (45±43meters per km x 10km) would be an astounding 450±430 meters in difference. Nevertheless due to lack of evidence, other factors are involved in reason to the difference in distance covered such as stride length which is based on limb length and stride frequency which is based on cadence (Hunter et.al 2002), (Mercer et. al, 2003), ( Esteve et.al 2008). This can be seen based on the results obtained where running and walking on the treadmill at different speeds of 11km/h and 5km/h respectively have a significant difference of 65 meters (p<0.05) t=" 5.740," df="58,">

REFERENCES

Bundle, M., Hoyt, R., & Weyand, P. (2003). High-speed running performance: a new approach to assessment and prediction Journal of Applied Physiology, 95, 1955-1962.

Ceci, R., & Hassmen, P. (1991). Self-monitored exercise at three different RPE intensities in treadmill vs field running. Medicine & Science in Sports & Exercise, 23(6), 732-738.

Crouter, S., Esten, P., & Brice, G. (2001). Comparison of incremental treadmill exercise and free range running. Medicine & Science in Sports & Exercise, 33(4), 644-647.

Hall, C., Figueroa-Galvez, A., & Kanaley, J. A. (2004). The energy expenditure of walking and running on a treadmill and track: Comparison to prediction equations. American College of Sports Medicine, 36(5).

Jones, A. M. (1996). A 1% treadmill grade most accurately reflects energetic cost of outdoor running. Journal of Sports Sciences, 14(4), 321-327.

Kubukeli, Z. N., Noakes, T. D., & Dennis, S. C. (2002). Training Techniques to Improve
Endurance Exercise Performances. Sports Med, 32(8), 489-509.

Laursen, P. B., & Jenkins, D. G. (2002). The Scientific Basis for High-Intensity Interval Training: Optimising Training Programmes and Maximising Performance in Highly Trained Endurance Athletes. Sports Med, 32(1), 53-73.

Mercer, J. A., Devita, P., Derrick, T. R., & Bates, B. T. (2003). Individual Effects of Stride Length and Frequency on Shock Attenuation during Running. Med. Sci. Sports Exerc., 35(2), 307–313.

Meyer, T., & Welter, J. (2003). Maximal oxygen upake during feild running does not exceed that measured during treadmill exercise European Journal of Applied Physiology, 88, 387-389.

Nummela, A., Hamalainen, I., & Rusko, H. (2005). Comparison of maximal anaerobic running tests on treadmill and track. Journal of Sport Sciences, 25(1), 87-96.

Polar. S1 foot pod™ Product support: Polar International

Pugh, L. (1970). Oxygen intake in track & treadmill running with observation on the effect of air resistance. Journal of Physiology, 207(3), 823-835.

Riley, P. O., Dicharry, J., Franz, J., Croce, U. D., Wilder, R. P., & Kerrigan, D. C. (2008). A Kinematics and Kinetic Comparison of Overground and Treadmill Running. Med. Sci. Sports Exerc., 40(6), 1093–1100.

White, S. C., Yack, H. J., Tucker, A, C., & Lin, H.-Y. (1998). Comparison of vertical ground reaction forces during overground and treadmill walking. Med. Sci. Sports Exerc., 30(10), 1537-1542.

Resistance training for 100m (Starting Block)

Introduction
Sprinting is the art of running as fast as possible. Power and coordination are the essential ingredients in the production of speed. Coordination can be improved through practicing good running mechanics. Speed is mostly an inherent factor where both coordination and speed can be improved through proper training. Sprinting can be broken down into four phases which is the start, acceleration, maintaining momentum and the finish.
However the two main components that increase speed are stride length and stride frequency. The sprint start is a motor skill which refers to a motor skill as an action or a task that has a goal and that requires voluntary body and limb movement to achieve the goal. Specifically, the sprint start could be categorized as a gross, continuous, closed motor skill. It’s a gross skill because it involves large musculature and the precision of movement is not as important to the successful execution of the skill as it is for fine motor skills. It is considered continuous because the performer determines the beginning and end points of the skill and they are not specified by the skill itself. On the open-closed continuum the sprint start is closer to the closed anchor point than the open, since it takes place under fixed, unchanging, environmental conditions (Magill, 1993).
A starter gives three commands to start a sprint race. These are "On your marks"; "Set" and then "Go" or else a gun are fired. When the athlete hears the initial command, "On your marks", he/she moves forward and adopts a position with the hands shoulder width apart and just behind the starting line. The feet are in contact with the starting blocks and the knee of the rear leg is in contact with the track. On hearing the command "Set" the athlete raises the knee of the rear leg off the ground and thereby elevates the hips and shifts the centre of gravity up and out. Then on the command "Go" or when the gun is fired the athlete reacts by lifting the hands from the track, swinging the arms vigorously and driving with both legs off the blocks and into the first running strides.

Need Analysis

 Biomechanics of Sprinting- Block Start
The start requires the body to overcome inertia, thereby initiating movement. Three basic laws of physics explain how the body can initiate movement. Newton's first law states that a body at rest will remain at rest unless some force induces a change in the resting state. The start stage requires a combination of explosive muscle contractions which leads to a production of great force. Newton's second law states that the production of force is a combination of the athlete's body mass and acceleration. Once the force into the blocks has been created, the blocks produce a subsequent reaction, which propels the body forward from the starting blocks. This occurs due to the premise of Newton's third law - for every action there is an equal and opposite reaction.
When setting the starting block, a simple approach is to place the knee of the rear leg opposite the instep of the front foot and then to move forward with the hands until the body weight is directly over the hands and the arms are vertical. The ideal angles of the legs in the "set" position in a sprint start using starting blocks are:
• Leading knee angle - 90 degrees
• Rear knee angle - 120 degrees

The following measurements, with the athlete in the "set" position, will be required:
• AL (Arm Length) - vertical distance from the midpoint of the shoulder to the ground
• BL (Back length) - distance from the midpoint of the shoulder to the midpoint of the hip
• ULL (Upper leg length) - distance from the midpoint of the hip to the midpoint of the knee
• LLL (Lower leg length) - distance from the midpoint of the knee to the bottom of the shoe
• FL (Foot length) - distance from the midpoint of the ankle to the point of contact with the toes to the ground

In order to clear the starting blocks on the command "Go" the athlete must produce a force over a certain time period. The product of this force (F) and the time (t) is known as the impulse of the force.
Impulse = F x t
A useful relationship, impulse-momentum relationship, can be obtained by substitution as follows:
F = ma. m = mass a = average acceleration
However, a = (vf - vi)/t.....vf = final velocity.....vi = initial velocity
Therefore, F = m(vf - vi)/t Or, F = (mvf -mvi)/t
Hence, Ft = mvf - mvi
This equation states that the impulse of the force is equal to the change in momentum that it produces. When an athlete is in the starting blocks his/her initial momentum is zero (mvi = 0). In addition, the mass of the athlete is constant and because of this the velocity of the athlete on leaving the blocks is directly proportional to the magnitude of the impulse exerted on the blocks but opposite in direction. The greater the impulse exerted the greater the velocity of the athlete. As exerting a high force for a long period of time produces speed from the crouch start Warden (1986).


Movement of 100m sprinter (block start) and muscles involved
Phase 1-"On Your Mark"
Kneel. Place feet correctly located in the blocks and place feet firmly against pedals so toes barely touch ground, with the power foot in the front pedal. Heels are off the pedals and the toes are curled under and touching the track. Rear-leg knee is resting on the ground. Place hands shoulder-width apart behind start line. Place fingertips down, thumbs pointing in toward each other, creating an arch between the index fingers and thumb, parallel to the start line. Roll body forward slightly, shoulders back and vertically above or slightly forward of the hands keeping arms straight and rigid but not locked at the elbows .Distribute weight evenly over hands and back knee. Hold and neck up in line with spine. The muscles involved are (anterior and lateral) deltoid, sternocledomastoid, erector spinae, biceps brachii, brachioradialis, pectoralis major, gluteus maximums, bicep femoris, vastus lateralis, gastrocnemius, and soleus. Figure 1.2: On your mark


Phase 2-Set!
From "on your mark" position, lift hips from ground slightly higher than shoulders, front knee bent approximately 90 degrees, rear knee bent 110 degrees to 120 degrees. Keep arms straight, but not locked. Shoulders vertically above or slightly forward of the hands and Feet pushed hard back into the blocks. Distribute weight evenly over hands. Focus down the track. Back and head form a straight line. Concentrate on reacting to sound of gun or start command - driving out of blocks. Hold the breath. Muscles involved are (anterior, posterior and lateral) deltoid, brachioradialis, sternocledomastoid, lattisimus dorsi, erector spinae, biceps brachii, pectoralis major, gluteus maximums, quadriceps, hamstring, rectus abdominis, gastrocnemius, and soleus.

Phase 3-Go!
Exhale, drive the arms hard and drive the back leg forward into a high knee action. Extend the whole body so there is a straight line through the head, spine and extended rear leg (body approx. 45 to 60 degree angle to the ground) Keeping low, relaxed and drive out of the blocks - do not step or jump out of the blocks. Muscles involved are (anterior, posterior and lateral) deltoid, teres minor and major, scapularis, brachioradialis, sternocledomastoid, lattisimus dorsi, erector spinae, biceps brachii, triceps, pectoralis major, rectus abdominis, external obliques, gluteus maximums, Quadriceps, hamstring, gastrocnemius, and soleus.

Injury
Injury during 100m block start
- Hamstring injury/sprain/tear
- Quadriceps injury/sprain/tear
- Achilles tendonitis/rupture
- Patellar tendon rupture
- Ankle sprain
- TFCC tear (Triangular Fibro Cartilage Complex)
- LBP (Lower Back pain)

Energy system used
The energy system used by a 100m sprinter is the ATP-PC system or the Phosphagens system (anaerobic) where the intensity of the activity is high and short duration without the usage of oxygen. In this system, ATP (adenosine triphosphate) is hydrolyze to make ADP (adenosine diphosphate) and energy. The enzyme that is use in hydrolyze process is myosin ATPase.

ATP Myosin ATPase ADP + Pi + Energy

On the other hand, the enzyme called Creatine Kinase will synthesis ATP and creatine from ADP and PC (Creatine Phosphate).

ADP + PC Creatine Kinase ATP + Creatine

Since the storage of PC in the muscle is small, thus the total amounts of ATP that can be produced are limited therefore only lasting for a few seconds.

Training program
100m sprint is a sport event well known for its superb speed, strength, agility and power. Researchers have shown that resistance training is a method that is needed and important to enhance performance. By undergoing resistance training, the benefits are:
- Increase the force for the starting kick-off.
- Increase the speed of out of the block.
- Increase power of acceleration and take-off.
- Increase muscular balance for the antagonist muscle group.
- Increase reaction time and coordination.
- Increase speed muscular endurance.
- Increase the stabilization of the joints.
- Increase lean body mass.
- Increase self-confidence.
- Reduces injury.
- Rapid recovery from injury

Perioidization

Periodization was first introduced by Russian scientist Tudor Bompa (1960) who is considered to be the father of periodization. What he suggests is to have different training regimes throughout a whole year by changing training variables such as Frequency, Duration, Volume and Intensity. This is to allow adequate recovery periods for a larger, more positive outcome of physical training which may also effect athletes psychologically. An example is as shown below.

Variables involved

Phase
How long? Frequency Duration Intensity Volume
Prep 4-8 weeks High Short-Medium Very little Low
Base 12-24 weeks High Medium- High Moderate Moderate to High
Build 4-8 weeks Moderate-High High Heavy Moderate
Peak/Race 3-5 weeks Moderate Short Heavy Low

Program Design

This program is designed following the training example of the national 100m sprinter before pre-competition phase during specific preparation phase. In this Phase, the needs analysis for the 100m sprinter is to increase mainly strength and fair amount of speed, power and agility. Therefore, the exercise focuses on all major and minor muscle must be trained. Example;

Athlete
Age : 21 years and above.
Gender : Male
Sport : Athletics 100m Sprint.
Skill : Block Start.
Phase : Specific preparation phase (SPP) before pre-competition.
Objective : i. Increase specific muscular strength in the athlete.
ii. Increase specific power in the athlete.
iii. Increase the speed and agility of the athlete.
Assumption : The athletes have gone through vigorous strength and conditioning training at general preparation phase (GPP)
Frequency : 2 times per week
Training : Day 1 (3 sets, 4-6 repetitions- rest period 3-4 minutes,
explosive +ve, control –ve tempo or speed)

Exercise Sets Reps Load (%)
Chest Press (Machine) 3 4-6 80-85
Latt Pulldown (Machine) 3 4-6 80-85
Lateral Shoulder raise (Machine) 3 4-6 80-85
Rear Shoulder raise/Rear Fly (Dumbbell) 3 4-6 80-85
Shoulder press (Dumbbell) 3 4-6 80-85
Biceps Curl (Dumbbell) 3 4-6 80-85
Triceps Extension (Dumbbell) 3 4-6 80-85
Upright row (Dumbbell) 3 4-6 80-85
V Abdominal crunch 2 20 Depending on athlete
V Back extension 2 20 Depending on athlete
Cross Crunch (Swiss ball) 2 20 Depending on athlete

Training -Day 5 (3sets, 4-6 repetition- rest period 2-4 minutes, explosive
Execution and control relaxation tempo or speed.

Exercise Sets Reps Load (%) of 1 RM
Power Cleans 3 8-10 70-75
Deadlift 3 8-10 70-75
Squats (Machine) 3 4-6 80-85
Hamstring curl (Machine) 3 4-6 80-85
Leg extension (Machine) 3 4-6 80-85
Calf Press (Machine) 2 20 Depending on athlete
Reverse Calf Press (Dumbbell) 2 20 Depending on athlete
Abductor (Machine) 3 4-6 80-85
Adductor (Machine) 3 4-6 80-85
Abdominal crunch (Machine) 2 20 Depending on athlete
Back extension (Machine) 2 20 Depending on athlete


• Core exercise

- V crunch ( Hip Flexors, Rectus Abdominis, Transverse Abdominis)
- V Back extension ( Hip Extensors, Erector Spinae, Transverse Abdominis)
- Abdominal Crunch ( Rectus Abdominis, Sternocleidomastoid)
- Back extension ( Erector Spinae, Transverse Abdominis)
- Cross crunch ( Rectus Abdominis, Transverse Abdominis, Internal & External Obliques)

• Chest exercises (Pectorialis Major & Minor, Triceps, Deltoids)
- Bench Press

• Shoulder exercises
- Posterior Shoulder raise/Rear Fly (Posterior Deltoids, Rhomboids Transverse Abdominis)
- Lateral Shoulder raise (Medial Deltoids)

• Arm exercises

- Biceps curl (Biceps Brachii)
- Triceps extension (Triceps Brachii, Rotator Cuff as stabilizers)

• Back exercise
- Latt Pulldown (Lattisimus Dorsi, Posterior Deltoids, Biceps Brachii)
- Upright row (Deltoids, Bicep Brachii, Transverse Abdominis)
- Back extension (Erector Spinae)

• Leg exercise
- Squats (Gluteus Maximus & Medius, Hamstrings, Quadriceps)
- Leg extension (Quadriceps, Hip Flexors)
- Hamstring curl (Hamstring, Gastrocnemius)
- Calf press ( Gastrocnemius, Soleus, Plantaris, Extensor Digitorum Longus, Extensor Hallucis Longus)
- Reverse calf press (Tibialis Anterior, Flexor Digitorum Longus, Flexor Hallucis, Fibularis Tertius/Peroneus)
- Adductor (Adductor – Magnus, Longus, Brevis, Gracilis-, Pectenius)
- Abductor (Piriformis, Gluteus – maximus, medius, minimus-, Tensor Facia Latae)
- Dead Lift (Hamstrings, Erector Spinae, Transverse Abdominis)
- Power Cleans (for development of total body explosive strength and power)


CONCLUSION
In conclusion, weight training program for 100m sprinter can help increase performance in training by preparing the muscle for intense 100m training and in competition where it can be a great advantage on the starting block where it is said to be the determining factor of winning or losing.

References

1. Bill Pearl (1982). Keys to the Inner Universe. California: Physical Fitness architects.

2. Powers, S. K & Howley, E. D. Exercise Physiology 6th Ed. 2007

3. Bruno Pauletto (1991). Strength Training for Coaches. United States of America: Human Kinetics.

4. Fahey, T. D. (2004). Basic Weight Training for Men and Women. New York: McGraw-Hill.

5. Hay, J. G. (1993). The Biomechanic of Sports Techniques. New Jersey: Prentice Hall.

6. Muscle Anatomy. (n.d.). Retrieved February 2, 2008, from www.shutupnlift.com

7. Muscle Anatomy and Function. (n.d.). Retrieved February 10, 2008, from www.sports-fitness-advisor.com

8. Muscle Physiology. (n.d.). Retrieved February 2, 2008, from www.healthline.com

9. Seeley, R.R (2006). 7th ed. Anatomy & Physiology. New York: McGraw Hill

Walking Gait: Male & Female vs. Treadmill & Overground

Kerrigan et al.,1998 and White et al., 1998

Introduction

Gait by definition is the manner of how humans or animals move from one point to another. This ‘travelling’ is done by movement of various joints at different points of time. It can be referred to walking or running pattern. “Walking involves progression by alternating periods of loading and unloading” (Wikipedia). Walking and running gaits can be divided into two main phases, namely the stance and swing phase. The time spent in these two phases varies greatly, being dependant on the velocity of movement. When walking, most time is spent in the stance phase and while running, most time is spent in the swing phase. This ensures a minimum contact time with the ground while producing larger ground reaction forces to propel the runner upward and forward with more velocity.

Technology can now be used to analyze gaits with piezoelectric plates that measure ground reaction forces and high frequency infrared cameras. This would be beneficial to individuals who are biomechanically challenged (e.g. flat foot, muscular imbalances and injuries). The results of gait analysis can then be used by physical therapists and doctors to improve performance of athletes and also quality of life for the general population.

Treadmills are widely used in health and fitness facilities as well as sports institutes. In nations where the weather is too extreme (e.g. too hot or too cold) outdoor/over-ground walking and/or running may limit training volume which ultimately leads to a decreased acceleration in improvement of physical fitness for competition. The question is whether treadmill walking gait fully replicates outdoor/ over-ground running as treadmill walking may negatively affect running patterns and gait leading to decreased performance during competition.

While it has been established that the energy cost of treadmill running is lower compared to outdoor running, one author (Jones, 1996) recommended an increase of 1% gradient for energy expenditures similar to outdoor running. This may however lead to further changes in running gait on a treadmill.

The purpose of this review is to recognize the differences between treadmill and outdoor running whether positive, negative or neutral. Another aspect reviewed is the ground reaction forces experienced by a walker, running either on a treadmill and outdoors. Two journal articles are reviewed and compared with hope of answering these questions.

Review of literature

Two papers titled Gender Differences in Joint Biomechanics During Walking (Kerrigan et al., 1998) and Comparison of Vertical Ground Reaction Forces During Over Ground & Treadmill Walking by White et al. 1998 was selected for review. This review is to compare the difference between the two studies under the roof of walking gait. The relevance of this review is to establish whether or not there is a difference in 1) male and female gait and 2) gait difference leading to change in ground reaction forces (GRF) between over ground and treadmill walking.

Gender Differences in Joint Biomechanics During Walking, Kerrigan et al., 1998

This study was on the effect of gender on specific joint biomechanics during walking and assumed that there were difference between male and females. They hypothesized that quantitative analysis would reveal the differences in kinetic and kinematic forces between male and female subjects. These authors studied a total of 99 subjects (49 female and 50 male) which proved to be sufficient for data collection in contrast to many other studies which studied one gender predominantly with insufficient subjects. The main objective of the study was to establish the difference in hip, knee and ankle biomechanics of male and female subjects during walking. They also intended to look for specific joint difference (kinetic and kinematic) between the two genders.

In the author’s literature review, it was reported that females have the same or slightly shorter stride length compared to males but tended to increase their cadence (frequency of steps) to compensate for speed. However, both genders were shown to have the same comfortable speed of walking with similar velocities. The author’s findings were similar to those previously found.

The author studied 9 parameters of gait between male and female subjects. They categorized their results with statistically significant difference (P < 27 =" 0.0019)" style="">

Discussion

Kinematic and kinetic differences between genders were observed by the authors. They measured a total of 27 parameters. It was found that females had greater peak hip flexion and less knee extension prior to initial contact in terms of kinematic parameters. Females also had greater knee flexion moment in the pre-swing phase and greater peak knee absorption (kinetic parameters). These findings were all significant.

Other siginificant findings were that female had greater peak knee flexion, ankle plantar flexion, hip power generation in loading response, knee extension moment (at initial contact) and ankle power generation in pre-swing (0.00019

<0.05)>

Both male and female had very similar gait patterns with only 5 out of 27 significantly different parameters. The potential explaination for an increased hip flexion in females could be a result of a larger stride length in relation to height, which directly correlates with an increased use of hip flexors. The greater forces (kinetic) and increased kinematic paramaters are seen because of their increased in walking velocity (cadence x stride length) which generally requires more mechanical work to be performed. In a different paradigm, the increases kinetic and kinematic parameters can be caused by naturally higher forces generated by the limbs which naturally creates a higher cadence.

Comparison of vertical ground reaction forces during over ground and treadmill walking, White et al., 1998

Study by White at al. was to compare the difference of vertical ground reaction forces during over ground and treadmill walking. The authors studied 24 subjects who performed walks at 3 speeds categorized as slow, normal and fast. Before performing the study, the subjects were instructed to walk for 3-5 minutes on a 12-m walkway with an audio metronome to set a ‘natural’ cadence for accurate placement of foot on a piezoelectric force plate. The subjects were not aware of the placement of the force plate which was hidden under the floor to ensure no adjustment in stride length when walking was made. This proves to be a good method in setting the walking pace for the subjects. The authors recorded 6 successful over ground walking trails at each walking speed (slow, normal, and fast). Every treadmill walking trials were recorded with a video camera set perpendicular to the sagital plane. Vertical ground reaction forces (GRF_v) was monitored and recorded using two piezoelectric force plates. These force plates were placed under the treadmill belt and made flat to the upper surface of the treadmill. Each step taken by the subjects (determining the speed) is given cue by an audible metronome (e.g. 20 beats per minute on a metronome was set for slow speed).

Vertical ground reaction forces measured was over a 30s data collection interval for each speed (slow, normal and fast). The measures included; 1) peak force during weight accepted, 2) minimum force in mid-stance, force peak in the last half of stance and the time from initial foot contact to each of the peak forces. Force magnitudes were also determined.

Other measures include cadence (steps per minute), stride length (horizontal distance from initial foot contact to next foot contact of the ipsilateral foot and walking speed were determined by video records for the over ground trials.

The finalized vertical ground reaction force data was collected and averaged over 5 over ground contacts for left and right foot. Force magnitudes were determined in Newtons (N). White et al. found that on average, no significance was found on cadence, walking speed and stride length between the two modes of walking although cadence and walking speed were slightly higher for the treadmill trials. Patterns of vertical ground reaction forces appeared similar between over ground and treadmill trials. Correlation was reported to be 0.998, 0.983 and 0.983 for the slow, normal and fast walking speeds respectively.

Findings that were significant in this study include force magnitude during mid and late stance during normal and fast walking speed while mid stance force was higher in normal and fast treadmill walking trials. However, peak force through late stance was lower for normal and fast walking speeds in treadmill walking. The higher force recorded during the mid-stance in treadmill walking during this study was initially thought to be because of a slower walking speed and shorter stride length. This theory however is not applicable to this study as walking speeds were equal. One study by Nelson et al. suggested that the higher forces generated in mid-stance on a treadmill was because of variables in limb motion which tended to be altered when treadmill speed was constant. This is a result of a decreased acceleration-deceleration mechanism.

A relationship between walking speed and forces generated during the early and late stance phases was also established. A higher force generation during the early stance was recorded during a slower walking speed as opposed to faster walking speeds. This can be explained with the same acceleration-deceleration theory suggested by Nelson et al. where during walking, there is more deceleration of the subject and treadmill belt.

Conclusion

The main objective of these two studies is to determine the difference in gait between the 4 variables, namely male and female gender and also gait on over ground and treadmill walking.

The study by White et al.,1998 was very precise, covering explanations of all methods used. Some of the mathematics and calculations behind several aspects such as cadence, stride length and walking speed were also clearly explained. This is beneficial for individuals who are less knowledgeable in this specific area of biomechanics. Their findings are beneficial for practitioners who wish to apply treadmill walking for various populations (e.g. rehabilitative) on the treadmill.

The study by Kerrigan et al. 1998, in contrast lacked several fundamentals; in fact one page of the journal article was missing. This paper however proved to show some significant results regarding gender differences in kinetic and kinematic parameters during walking gait.

References

Jones, A. M. (1996). A 1% treadmill grade most accurately reflects energetic cost of outdoor running. Journal of Sports Sciences, 14(4), 321-327.

Kerrigan, D.C., Todd, M.K (1998). Gender Differences in Joint Biomechanics During Walking: A Normative Study in Young Adults. Am J Phys Med Rehabil, 77, 2-7.

White, S.C., Yack, H.J. (1998). Comparison of vertical ground reaction forces during overground and treadmill walking. Medicine & Science in Sports & Exercise, 30(10), 1537-1542

http://en.wikipedia.org/wiki/Gait (human)

Caffeine & Exercise Performance: A Brief Review

Introduction

One of the earliest study on the effects of caffeine (CAF) and physical performance was proved by a researcher (Laties, 1964) who tested the effects of 500mg of CAF on work output using a ‘Mosso Ergometer’ and found that work output increased. However, that is only one of the many components that CAF may have an effect on. Other components include increased aerobic performance, strength and reaction time (T. Graham, 2001).This drug however, comes along with some adverse side effects such as dehydration and insomnia. Researchers found that caffeine did not negatively affect sports performance.

This substance was once banned by the IOC due to scientific findings which led to recommendation of ban from use in sport competition. The level deemed illegal was 12µg/mL which is around 600-800mg of caffeine (6-8 cups of brewed coffee). The ban, however has been lifted in 2004 as it is difficult to draw a line to what constitutes consumption of this drug to be of purely ‘doping’ in nature. What makes it even more difficult is that the use of this drug is widely accepted by the general population and more so, used by athletes today. Consumption of caffeine can be said to be normal as many of the food and drinks consumed contains as slight amount of this substance. This includes coffee, tea, chocolates and soft drinks. Caffeine composition may vary widely from one food source to another. An elevated level of this substance (> 70µmol/L) in the human body can be said to be normal.

The exact mechanism on how caffeine works as a performance booster is not clearly understood by scientists as CAF creates a chain of reactions to which is hard to pin-point exactly which starts first. These actions and reaction also occurs simultaneously. However, caffeine acts mainly as an adenosine receptor inhibitor and has an effect on various parts of the human body. This includes the brain, heart, skeletal muscle and adipocytes (Paluska, 2003). In relation, an increased in mobilization of free fatty acids (FFA), reduced reaction time and reduced fatigue are some of the mechanisms hypothesized to increase performance. An example of this is demonstrated by (T. Graham, 2001) where CAF stimulates secretion of adrenaline and thus creates secondary metabolic responses (e.g. increased blood circulation). This response can be from either neural (beginning from the brain) or cardiovascular changes affected by CAF. The fact that CAF may work as a placebo should not be dismissed (Brukner & Khan, 2007)

The purpose of this paper is to briefly review the use of caffeine with the goal of improving exercise performance. This includes the theory of mechanism involved, optimal dosage, time, method of consumption of CAF, and also the types of exercise caffeine plays a role on.

Caffeine as an ergogenic aid

Caffeine was and is still being widely used as an ergogenic aid to endurance performance. One study reported that improvements of up to 20% were seen in athletes who consumed caffeine 1-3 hours prior to exercise. (Douglas G. Bell & McLellan, 2002). The effects of caffeine on various aspects of exercise performance were studied by researchers. Most commonly, the effects of caffeine on endurance performance where the authors concluded that the question to ask is by what degree does caffeine induce performance increases instead of whether caffeine does improve performance.

It has also been proven that caffeine does improve power output in cycling where (Ivy et al., 2009) found an increase of 7.3% in power output over a 2 hour long cycle exercise period. Another study (E. M. R. Kovacs, J. H. C. H. Stegen, & F. Brouns, 1998) had similar findings in their study on trained athletes who consumed a carbohydrate and electrolyte solution with addition of caffeine. These authors found that there was a positive co-relation between ingestion of this solution (carbohydrate, electrolyte and caffeine) on power output in their testing protocol.

In a more functional test, a paper published was on the time difference in 100m swimming trials where the author found that there was significant difference in mean swim times between caffeine and placebo groups (Collomp, Anderson, & Fraser, 2000).

Other studies regarding power maximal power output were by (Anselme, Collomp, Mercier, Ahmaiedi, & Prefaut, 1992) who studied participants with CAF treatment on Wingate tests. These authors found that CAF treatment only affected performance in the 6s test and not the 30s test. There were no differences between the groups in relation to maximal anaerobic power generated and fatigue (Anselme et al., 1992).

The possible explanation to how caffeine increases athletic performance is through increased adrenaline and fat oxidation while sparing more limited sources of glycogen (Randle Effect). This theory was found by (Essig, Costill, & Van Handel, 1980)Plenty has changed since, most researchers only study the effects of caffeine and not the mechanism. With more recent data, the theory proposed by these authors may not be reliable/ valid even though plasma FFA levels were elevated. More recent studies suggest that this theory lacked evidence, yet these newer studies tend to be more descriptive rather than being critical with excluding measures of plasma caffeine and catecholamine levels. These two levels are crucial to Essig’s theory relating to glycogen sparing. Researchers also found that FFA uptake did not increase and led to respiratory exchange ratio (RER) to remain constant between both users and non-users of caffeine.

Consumption of Caffeine

There are various methods of CAF consumption (e.g. intravenous injection). However, the most conventional way is to consume orally. Caffeine is contained in many foods and beverages as mentioned above but this substance is also found in medications such as cough mixtures and weight loss products. Many sports drinks and gels are also marketed with caffeine as an additive to promote sales along with its ergogenic benefit.

Some, if not many gym-goers tend to turn to coffee or other caffeine rich sources for their caffeine dose before exercising. This may prove to be a good deed as researchers found that caffeinated coffee does increase exercise capacity especially in prolonged exercise (>30 minutes)

Caffeine in conjunction with other compounds

The effectiveness of caffeine may be increased or decreased if consumed in conjunction of other ergogenic aids (e.g. creatine). As caffeine inhibits various adenosine receptors, the body may not react naturally as it would to these substances without caffeine.

Several researchers (Eva M. R Kovacs et al., 1998) studied the effects of these sports (glucose + electrolyte) products with the caffeine additive. Their findings show that caffeine did not negatively co-relate with the sports drink containing either glucose and electrolytes or only glucose/electrolytes. These authors also found that the additive did not negatively affect performance and the utilization of glucose and electrolytes.

In contrast, one study (Vandenberghe et al., 1996) showed that caffeine negatively affected the utilization of creatine. 9 male volunteers participated in the study with Cr 0.5g/kg/day and 0.5g/kg/day + CAF 5mg/kg/day prescribed. The exercise protocol for their experiment was three consecutive isokinetic interval muscle contractions with 2 minute rest periods. Muscle ATP concentrations were reported to remain constant over the three experimental conditions. Phospho-creatine concentrations in muscle were increased in both groups by 10-23%. The researchers found that the creatine only treatment proved to be ergogenic but had zero co-relation towards performance when caffeine was included in the equation (creatine + caffeine). This information would be beneficial for bodybuilders who normally consume creatine and caffeine pre-training.

Caffeine was also reported to augment effects of non-steroidal anti-inflammatory drugs(NSAIDS) such as aspirin and ibuprofen (Sawynok & Yaksh, 1993). More research is required in this area for further clarification and confirmation as (Zhang et al., 1997) found contradictory results in their review on the same topic.

Prescription

(Pasman, Van Baak, & Jeukendrup, 1995) found that dosages as low as 3mg/kg bodyweight has shown to have a positive effect on aerobic performance. Findings from Bruce et al. and Kovacs et al. found ergogenic effects when CAF was prescribed with sports drinks. These researchers had confirmed that a dosage between 3 to 6mg/kg is optimal for improving performance.

The optimal method of consumption relates to timing if ingestion and dosage. There have been various studies done to answer the question on prescription. Two main approaches were used; 1) single dosage and 2) repetitive dosage. Data has shown that plasma concentrations of CAF may be elevated with a single dosage for up to several hours, repeated dosage of CAF may prove to be beneficial to those who are caffeine ‘intolerant’, experiencing severe symptoms of gastric irritation with large doses of this substance. Other than the following, repeated dosages would not be required.

Another paradigm of caffeine ingestion is whether dosage prescribed was absolute or relative. Many studies had prescribed a relative dosage (mg/kg bodyweight), this include studies done by (T. E. Graham & Spriet, 1995; Pasman et al., 1995)on high intensity (80-85%) aerobic exercise in male and female subjects. These researchers had 4 groups for treatment purposes with varying dosages (mg/kg). The general outcome for these studies is an increase in aerobic performance for dosages between 2.2mg/kg and 9mg/kg with or without mixing with sports drinks (Bruce, Anderson, & Fraser, 2000; E. M. R. Kovacs, J. Stegen, & F. Brouns, 1998). There were higher dosages prescribed but did not reap any further benefits.

Absolute dosages were also prescribed in some studies and although there were positive results, they may not be reliable as it is not a good indicator of the true requirement to increase caffeine plasma levels. The variance may be up to an excess of 20% of that is required in smaller bodied individuals (e.g. women vs. men) (T. Graham, 2001). Another limitation is that only (Eva M.R Kovacs et al., 1998) tested for the changes in caffeine plasma concentrations and found that exercise does not influence caffeine absorption.

In relation to timing of ingestion, (Nehlig, 1994; Weir, Noakes, & Myburgh, 1987) suggested that ingesting caffeine 3 hours prior to exercise is best as plasma free fatty acids (FFA) is optimal due to caffeine induced lipolysis. This finding however has limitations as this hypothesis has not been tested and proven.

Adverse effects of caffeine ingestion

Negative effects may arise from lower tolerance/higher sensitivity of caffeine. It is hard to set a clear limit or range of the amount of caffeine is to be ingested before reaching the point where adverse effects kick in. However, one source (Canada, 2007) recommended that no more than 400mg caffeine be ingested in a day.

From the same source, it was reported that the side effects of caffeine may be more acute (changes in behaviour) in children than in adults. If caffeine is taken in moderation, it may increase alertness and ability to concentrate. If the personal limit is exceeded, it could lead to acute insomnia, headaches irritability and nervousness.

Looking at the long term effects of caffeine includes 1) general toxicity leading to muscle tremors, nausea and irritability, 2) increased heart rate, cholesterol and blood pressure, 3) negative calcium balance leading to decreased bone density and increased risk of fractures, 4) behavioural changes including but not limited to anxiety and attentiveness, 5) effects on reproduction in women who are still in childbearing age and men.

Dehydration is a common concern amongst caffeine users especially those who participate in sport. A decrease of only even 2% of total plasma volume may hinder performance drastically. However, one study (T. E. Graham, Hibbert, & Sathasivam, 1998) reported that there were no differences in urine excretion between users and non-users and was highly reflected by total fluid ingestion. In matters relating to fluid balance, several authors found similar findings where there we no effects of caffeine on sweat rate, plasma volume and core temperature. These findings however only studied the acute effects of caffeine (around 1 hour after ingestion), while in a longer period post-ingestion caffeine works as a mild diuretic. This was reported by (30) over 4 hours and if exercise did take place, this diuretic effect of caffeine was over-ridden.

Urinary caffeine excretion was found to be a poor indicator of plasma caffeine concentration and urinary caffeine concentration is highly variable. This makes it difficult to prescribe dosages required if sporting competition lasts for several consecutive days. Repetitive dosages would ensure plasma concentration of caffeine is elevated for optimal ergogenic effects to take place (Dogulas. G Bell & McLellan, 2003). Caffeine excretion through urination is however an indicator of ingestion of caffeine. Urinary caffeine concentrations were between 1.9 and 2.5 µg/ml and was not close to the IOC limit of 12µg/L in a study (Eva M. R Kovacs et al., 1998) which prescribed between 2.1mg/kg and 4.5 mg/kg.

Another potential negative effect is dependency and increased tolerance towards this substance. Just as any drug, the body adapts to it and over a time period, requires more for the effects of the drugs to take place.

Conclusion

Ingestion of caffeine for purpose of exercise may pose both positive and negative effects for the consumer. However, recommendations for caffeine consumption should be made for athletes as it may give them an edge during training and competition. Although some studies reported no effects of caffeine on exercise performance, none of the studies in this review found a negative correlation on consumption of caffeine in regards to exercise performance (T. Graham, 2001). It can be said that participants of all sports requiring an expenditure of a relatively large amount of energy will benefit from caffeine ingestion. Caffeine however may hinder sporting performance in those requiring accuracy and a steady heart rate such as shooting and archery. There were no studies found in regards to these sports.

Several authors have proven that only a small amount of caffeine is required to promote ergogenic benefits (Bruce et al., 2000; T. E. Graham & Spriet, 1995; Eva M. R Kovacs et al., 1998; Pasman et al., 1995). These levels that are required for ergogenic benefit does not come close to the limit set by the IOC (12µg/mL).

References

Anselme, F., Collomp, K., Mercier, B., Ahmaiedi, S., & Prefaut, C. (1992). Caffeine increases maximal anaerobic power and blood lactate concentration. European Journal of Applied Physiology & Occupational Physiology, 65(2), 188-191.

Bell, D. G., & McLellan, T. M. (2002). Exercise endurance 1, 3, and 6 h after caffeine ingestion in caffeine users and nonusers. J Appl Physiol, 93(4), 1227-1234.

Bell, D. G., & McLellan, T. M. (2003). Effect of repeated caffeine ingestion on repeated exhaustive exercise endurance. Medicine & Science in Sports & Exercise, 35(8), 1348-1354.

Bruce, C. R., Anderson, M. E., & Fraser, N. K. (2000). Enhancement of 2000-m rowing preformance after caffeine ingestion. Medicine & Science in Sports & Exercise, 32(11), 1958-1963.

Brukner, P., & Khan, K. (2007). Clinical Sports Medicine (3rd ed.). Sydney, Australia: McGraw Hill.

Canada, H. (2007). It's your health: Caffeine. Health Canada.

Collomp, K. A., Anderson, M. E., & Fraser, S. F. (2000). Benefits of caffeine ingestion on sprint preformance in trained and untrained swimmers. European Journal of Applied Physiology, 80(64), 337.

Essig, D., Costill, D., & Van Handel, P. (1980). Effects of caffeine ingestion on utilization of muscle glycogen and lipid during leg ergometer cycling. International Journal of Sports Medicine, 1, 86-90.

Graham, T. (2001). Caffeine and Exercise: Metabolism, Endurance and Performance. Journal of Sports Medicine, 31(11), 785-807.

Graham, T. E., Hibbert, E., & Sathasivam, P. (1998). Metabolic and exercise endurance effects of coffee and caffeine ingestion. J Appl Physiol, 85(3), 883-889.

Graham, T. E., & Spriet, L. L. (1995). Metabolic, catecholamine, and exercise performance responses to various doses of caffeine. J Appl Physiol, 78(3), 867-874.

Ivy, J. L., Kammer, L., Zhenping, D., Bei, W., Bernard, J. R., Yi-Hung, L., et al. (2009). Improved Cycling Time-Trial Performance After Ingestion of a Caffeine Energy Drink. International Journal of Sport Nutrition & Exercise Metabolism, 19(1), 61-78.

Kovacs, E. M. R., Stegen, J., & Brouns, F. (1998). Effect of caffeinated drinks on substrate metabolism, caffeine excretion and performance. J Appl Physiol, 85(2), 709-715.

Kovacs, E. M. R., Stegen, J. H. C. H., & Brouns, F. (1998). Effect of caffeinated drinks on substrate metabolism, caffeine excretion, and performance. J Appl Physiol, 85(2), 709-715.

Nehlig, A. (1994). Caffeine & Sports Activity: A Review. International Journal of Sports Medicine, 15(23), 215.

Pasman, W. J., Van Baak, M. A., & Jeukendrup, A. E. (1995). The effect of different dosages of caffeine on endurance performance time. International Journal of Sports Medicine, 16(30), 225.

Sawynok, J., & Yaksh, T. (1993). Caffeine as an analgesic adjuvant: a review of pharacology and mechanism of action Journal or Pharmacology(45).

Vandenberghe, K., Gillis, N., Van Leemputte, M., Van Hecke, P., Vanstapel, F., & Hespel, P. (1996). Caffeine counteracts the ergogenic action of muscle creatine loading. J Appl Physiol, 80(2), 452-457.

Weir, J., Noakes, T., & Myburgh, K. (1987). A high carbohydrate diet negates the metabolic effects of caffeine during exercise. Medicine & Science in Sports & Exercise, 19(2), 100-105.