caffeine effects caffeine benefits supplement guide what's new
Energy Systems







            -            Caffeine

            -            Sodium Bicarbonate

            -            Creatine Monohydrate

            -            Potassium Phosphate

            -            L-Carnitine

            -            Ginseng

            -            Glycerol


            This section explores the various mechanisms through which the above substances can effect human energy systems.  It outlines dosages and procedures for specific results in enhancing physical performance.



Scientific Name:                  Methylxanthine

Type of Nutrient:                   Stimulant drug of Central Nervous System

History:                                  Used for hundreds of years in form of tea and coffee beverages

How Supplied:                      Powder, Tablet, Liquid, Suppository

Natural Sources:                  Tea, Coffee, Guarana, Kola Nut

Used for:                                Reducing bodyfat and perception of effort.  Increasing workload capacity, muscle fibre recruitment, exercise intensity, endurance, alertness, concentration, and oxygen uptake, Glycogen sparing

Cost effectiveness:               Excellent

Safety:                                    Up to 600mg/day (7 cups of coffee) considered safe (Gilbert 1992)

Precautions:                          Should not be taken by pregnant women (has been linked with reduced bodyweight of the newborn) or people with heart problems (excessive doses can cause extra beats of left ventricle).  Can cause physical dependence at daily dosages of 350mg and above (about 4 cups of coffee).  5 grams and above can be a lethal dose (about 60 cups of coffee).


            Some Personal Trainers will be horrified at the thought of encouraging clients to consume caffeine.  However, its effects on physical performance and bodyfat reduction are too great and well documented to ignore.  Used prudently, caffeineís benefits can be made to outweigh possible risks. The following are caffeine benefits and effects...


            The most common beneficial finding of caffeine use is an increasing in burning of bodyfat as fuel (Costill et al 1978, IVY et al 1979).   For the use of Caffeine in fat reduction see Section III - Fat Loss. Click here




            In two related studies (Costil et al 1978, Ivy et al 1979) nine competitive cyclists were exercised to exhaustion on a bicycle ergometer.  After a dose of 330mg of caffeine, the cyclists improved their VO2 max by 19% over placebo.  In the second study (Ivy et al 1979) the cyclists rode an adjusting ergometer.  The resistance of the ergometer was constantly adjusted and an estimate of work determined.  Each cyclist was given 250mg of caffeine and a further 250mg administered over several divided doses.  The caffeine treatment resulted in a 7.4% increase in work production and a 7.3% increase in the maximum oxygen uptake.



            One recent study (Flinn S et al Int J Sports Med 1990;11:188-193) done here in Australia by Dr Lars McNaughton and colleagues at the Tasmanian Institute of Technology tested cyclists against themselves as controls under double-blind conditions, pedalling a cycle ergometer to exhaustion under progressively increasing workload.  Caffeine at 10mg/kg bodyweight, or a placebo, were given as a flavoured drink three hours prior to the test.  That is a dose of 800mg for an 80kg man.

            Results showed that the caffeine increased time to exhaustion by 18% and exercise intensity by 24%.  Thus, it allowed them to ride both longer and harder.  In addition, caffeine increased the use of free fatty acids for fuel thereby sparing glycogen.  It also raised the lactate threshold in relation to workload, suggesting that there was less build-up of lactic acid.  This is the level of benefit you could expect with correct caffeine usage.



            Caffeine has direct effects on muscle contraction (Alles et al 1942).  It acts on the skeletal muscle by increasing calcium permeability essential for muscle contraction (Foltz et al 1943).

            Excessive amounts of caffeine are not required for effects.  Researchers (Alles et al 1942) observed effects of caffeine on the muscle during exercise.  Caffeine (50mg orally) given one hour before the experiment produced higher muscle tension at low frequencies of muscle stimulation, suggesting a direct effect on muscle contraction.  This study showed that caffeine may be acting directly on the muscle in addition to the central nervous system in masking fatigue.

            Even though values for heart rate and oxygen consumption during one study were similar the caffeine made the work Ďfeelí easier.  It is likely that a lessening of the subjective ratings of effort was due to the effect of caffeine on neuronal excitability, possibly through a lowering of the threshold for motor-unit recruitment and nerve transmission.



            Caffeine is reported to decrease drowziness and promote a more rapid and clearer thought process.  Research reveals 85 to 250mg of caffeine increases the capacity for sustained intellectual effort and decreased reaction times.

            Studies of changes in brain activity show that caffeine does have arousing effects.  One way to measure this is to attach electrodes to a personís skull and record the patterns of electrical activity of his or her brain.  It has been shown that caffeine in a few cups of coffee causes the patterns to change from those typical of an awake and sedentary person to those of an alert and active person.


            Not all research has been in total agreement of caffeineís performance enhancing effects.

            Most of the work up till 1980 lacked the necessary controls to separate the effects of caffeine on sports performance from its effects in everyday life.  The latest and best research shows they are quite different.

            Numerous reviews lump together studies on sedentary people with studies on athletes and come to the conclusion that caffeine effects on performance are variable and inconclusive - and that a couple of cups of coffee before competition might help, or might not.

            The first error of these reviews is assuming that a sedentary person coaxed into exercise reacts the same way to caffeine as an athlete - they donít (Bucci LR Nutritional Ergogenic Aids).

            The second common error lies in confusing subjects who habitually use coffee, tea, cocoa, caffeinated soft drinks or chocolate with those who have a low daily intake of caffeine.  Like giving an alcoholic a six-pack and expecting him to keel over!  (Colgan). If your body has developed a tolerance to caffeine through prolonged use, then extra caffeine will not boost performance.

            Two detrimental effects commonly cited by writers on sports nutrition about caffeine are that it is well established as a diuretic (makes you lose water) and that it is thermogenic (raises metabolic rate and body temperature)  (Wager-Srdar SA et al Life Sci 1983;33:2431-2438).

            Athletes are often warned that caffeine can make them dehydrate and overheat.  But almost all the studies showing these effects were done with sedentary people.  Recent research using athletes as subjects found no diuresis or thermogenesis.  In fact caffeine ingestion has not been shown to alter fluid balance, sweat rate, total water loss, heart function, or blood electrolyte content during exercise (Can J Physiol Pharmacol 68:889, 1990; S Afr Med J 62:664,1982).  Separate studies from Ohio State University confirm that caffeine ingestion does not alter body fluid/hydration and does not increase heart rate during exercise (Med Sci Sports Ex 26: Abstract 1146, 1994).

            Sedentary people using caffeine would be advised to take a mineral supplement to safeguard against any deficiencies in iron, calcium, magnesium or sodium, and to drink plenty of water.



            The IOC (International Olympic Committee) permits an upper level of 12 micrograms per millilitre of urine.  This would be the equivalent of 12 milligrams per litre of water in the body of an athlete.  A male athlete who weighs 70kg and whose body composition contains 60% water will have about 42 litres of water in his body, as 0.6 x 70kg = 42, and a kilogram of water is one litre.

            If you multiply 12 milligrams by 42 litres, you will find that this athlete may consume about 500mg of caffeine to reach the legal limit.  But to allow for individualities and to play it on the safe side, I would recommend not exceeding 5mg/kg of bodyweight.  This would be a dose of 350mg.

            Depending on the individual, a range of 100 to 300 milligrams is considered a therapeutic dose.  350mg could be considered a very therapeutic dose.

            Such doses meet the level for a stimulant effect and are still legal under IOC doping guidelines.

            Excess caffeine can certainly mess you up.  One study in the American Journal of Psychiatry reports anxiety, irritability, delirium and hallucinations, brought on by caffeine during exercise (Stillner V et al Am J Psychiatr 1978; 135:855).

            Above a certain amount, more caffeine does not produce better effects, probably because its toxic side effects start to over-ride the benefits.  So there is no reason to take so much it sends you crazy.  1000mg is over the top for most athletes, especially if they abstain from caffeine in everyday life.

            Cyclists have been known to use 3000mg supporitories.

            Symptoms of intoxication include insomnia, restlessness, sensory disturbance such as tinnitus (ringing in ears), and flashing of light.  Large overdoses of caffeine can cause seizures.  It can cause headache and involuntary muscle contractions.

            Caffeine is capable of causing physical dependance in much the same way as other addictive drugs such as alcohol and nicotine.

            However, caffeine withdrawal symptoms, though uncomfortable, are not life threatening.

            To avoid physical dependence and minimize tolerance effects, caffeine dosages should be kept as low as possible and used intermittently; eg  Donít use caffeine during every workout, and every fortnight have one week off.  Also to maximise the benefits, avoid taking caffeine other than at training times.  ie.  Donít drink coffee, tea, coke or other food and drinks containing caffeine unless they are part of  your program.  The use of Grapefruit juice containing Naringin will also help stop the body from becoming de-sensitized to the effects of caffeine.



            Some people may experience difficulty getting to sleep if they train late in the day.

            A simple but powerful solution to this is to use a mental technique that relaxes the body and calms the mind, making sleep effortless and natural.

            Lying flat on your back in bed, arms to your side and legs slightly apart, place your attention on your breathing.

            Do not try to control it - just focus your attention on it.  Be aware of each breath in and each breath out.  Feel your lungs fill and then empty.  Feel your chest rise and fall.  Feel the air moving through your nose and then out.  As thoughts enter your mind, just let them go and bring your attention back to your breathing.  Do not try to do or think of anything - just be aware of your breathing.

            After approximately 10 minutes, you will enter a profoundly relaxed state.  Your brain wave frequency will slow down.  Instead of producing predominantly Beta waves (those which characterise an alert, awake state) your brain will start producing Alpha, Theta and Delta waves as you fall asleep.




            Recognizing that there can be significant variability in caffeine content for a given source, it is nonetheless useful to have representative values for each of the major sources.



            Ground roasted            85mg/150ml (5-oz cup)

            Instant                            60mg/150ml (5-oz cup)

            Decaffeinated               3mg/150ml (5-oz cup)



            Leaf or bag            40mg/150ml (5-oz cup)

            Instant                     30mg/150ml (5-oz cup)


Cola (except caffeine-free)            18mg/180ml (6-oz glass)

Cocoa, hot chocolate                      4mg/150ml (5-oz cup)

Chocolate milk                                 5mg/250ml (8-oz cup)

Caffeine 1g                                      1000mg





Lifestyle:  Active, trains 4 x week 2 years training  
AGE:  25  
Diet: High Protein, High Carb, Low Fat  
WEIGHT: 80kg


1/2 hr before training               250mg Caffeine

                                                  300ml Grapefruit juice


(FOR FAT LOSS, PHYSIQUE ENHANCEMENT -  See Section III Fat Loss under Caffeine.)


            Taken before a run, a bodybuilder could expect to run with less perceived effort, burn more body fat, have greater endurance and a greater VO2 max, than without it.

            Taken before a workout, a bodybuilder could expect caffeine to help him to increase the intensity; reduce perceived effort, increase the workload and help him concentrate better than without it.

            Taken before a contest a bodybuilder could expect caffeine to make him feel more alert, get a greater, more vascular pump, and appear more defined due to diuretic effect, than he otherwise would have.

Top 10 Benefits of Caffeine for Bodybuilders


1.            Increased Definition

2.            Increased Vascularity

3.            Greater Pump

4.            Increased Fat Burning

5.            Increased Workload Capacity

6.            Increased Endurance

7.            Increased VO2 Max (Oxygen uptake)

8.            Increased Workout Intensity

9.            Increased Alertness and Concentration

10.          Less Perceived Effort






AGE:   30
WEIGHT:  70kg
Lifestyle:   Active, trains 2 x week weight   3 x week runs 10 km
Diet: High Carb, Mod Protein, Low Fat  

            Event:  10 kilometre + race


            3 hours before  700mg * Caffeine            *WARNING: This dosage

                                     300ml Grapefruit juice            (10mg/kg) has the potential to

                                                                                  exceed the IOCís legal limit.

            5 minutes before   300ml Grapefruit juice


            Caffeine is known as an analeptic drug, or a substance that can restore strength, awake and invigorate.

 Click here to buy pure caffeine