Caffeine Dosage for Optimal Health and Performance
by Joe Giandonato, MBA, MS, CSCS 
Affectionately dubbed as the working world’s fuel, caffeine renders virtually immeasurable effects on physiological systems, which impact physical and mental performance. Given confounding media reports and poorly designed research studies, many medical professionals and fitness professionals are left to ponder what sources and dosages are required for optimal elicitation of caffeine’s effects.
Caffeine, a psychoactive stimulant, is composed of a white crystalline xanthine alkaloid. Xanthine is the final product of purine metabolism, which involves the breakdown of purine nucleotide structures such as DNA and ATP, and is present in most human tissues.
Alkaloids are chemical substances which are derived from plants and composed of carbon, hydrogen, nitrogen, and oxygen. Alkaloids are classified by possessing a nitrogen containing base and organic compounds which is comprised of one of the following: a heterocyclic compound containing nitrogen, possessing an alkaline pH, and having the capacity to demonstrate distinct physiological effects. Alkaloids, namely caffeine, are found in plants, including roots, seeds, leaves, and the fruit of plants. Cherries of the coffee plant and leaves of tea bushes are provide the most abundant source of the caffeine alkaloid.
Caffeine is consumed throughout the world to amplify physical and mental performance. Research indicates that strength athletes are likely to benefit from caffeine consumption prior to training. Caffeine ingestion has been linked to resistance exercise performance when training to failure and reducing perceived exertion and pain (1,2). Caffeine also boasts potent lipolyctic properties, helping exchange free fatty acids for usable energy.
Caffeine interacts with the CNS through the antagonization of adenosine receptors, in turn impacting the dopaminergic and neurotransmitter systems. By flooding the brain’s adenosine receptors, caffeine counteracts adenosine’s inhibitory role in neurotransmission, plausibly explaining why those consuming caffeine may demonstrate greater power output (3). Remember, the amount of muscular force is dependent on two factors: the number of motor units that are recruited and the firing rate, or discharge frequency, of the involved motor units. Research has also shown that caffeine boosts cognitive functioning and memory through the up regulation of brain derived neurotrophic factor (BDNF) located in the brain’s hippocampal region (4).
Before outright classifying caffeine as a performance panacea, we need to view caffeine as we do other drugs. Each drug comprises a dose dependent response. A dose too great or too little will prevent the desired effect from being realized. Similarly, tolerance to caffeine will become elevated over time, thus nullifying the effects of baseline supplementation.
As a strength and conditioning coach, aspirant top flight powerlifter, and an administrative professional who works long hours, I’ll tell you that caution must be practiced when supplementing with caffeine. If you are not presently supplementing with caffeine, but are interested in trying it out, I would suggest consuming no more than 200-300 mg of caffeine per day, an amount that can be found among two to four cups of brewed coffee per day. Consuming more than the recommended amount of 200-300 mg of caffeine per day may potentially trigger insomnia, nervousness, muscle spasms, tachycardia, hypertension, and irritability. Caffeine consumed later in the day may also affect sleep onset latency.
If you are already supplementing with caffeine, I would suggest avoiding it or reducing it during deload periods, restorative sessions, and as a means to suppress appetite. I’d also suggest pairing higher dosages of caffeine, usually an entire day’s worth (200-300 mg of caffeine) with higher intensity anaerobic training sessions. Personally, I love to drink a towering black cup of coffee prior to higher volume lower body sessions. I have found that ingesting caffeine only two or three times per week helps to keep my tolerance in check. I would also suggest analyzing the content of preworkout supplements, which may contain stimulants in addition to caffeine. In early 2012, reports emerged that some companies were including or lacing their products with DMAA, or 1,3-dimethylamylamine, a synthetically derived stimulant which has been linked to a number of deaths, for enhanced potency. Anecdotally, caffeine does the trick, provided you do not heighten your tolerance.
In summary, its best to use caffeine judiciously and preferably in palatable forms such as coffees or teas. Supplements containing compounds in addition to caffeine should be closely analyzed for potential efficacy and safety risks prior to use. Caffeine should never substitute for a lack of sleep or poor diet. Learn how Caffeine helps Bench Press Strength here
References
1.Duncan MJ, Stanley M, Parkhouse N, et al. (2013). Acute caffeine ingestion enhances strength performance and reduces perceived exertion and muscle pain perception during resistance exercise. European Journal of Sport Science, 13, 392-399.
2.Duncan MJ, Oxford SW. (2012). Acute caffeine ingestion enhances performance and dampens muscle pain following resistance exercise to failure. Journal of Sports Medicine Physical Fitness, 52, 280-285.
3.Doherty M, Smith P, Hughes M, Davison R. (2004). Caffeine lowers perceptual response and increases power output during high-intensity cycling. Journal of Sports Science, 22, 637-643.
4.Costa MS, Botton PH, Mioranzza S, et al. (2008). Caffeine improves adult mice performance in the object recognition task and increases BDNF and TrkB independent on phospho-CREB immunocontent in the hippocampus. Neurochemistry International, 53, 89-94.