Caffeine use for sport

See also: Bodybuilding supplement and Doping in sport

Caffeine use for sport is a worldwide known and tested idea. Many athletes use caffeine as a legal performance enhancer, as the benefits it provides, both physically and cognitively outweigh the disadvantages. The benefits caffeine provides influences the performance of both endurance athletes and anaerobic athletes. Caffeine has been proven to be effective in enhancing performance.

Caffeine is a stimulant drug.^[1] Once consumed, it is absorbed in the stomach and small intestine as well as being circulated throughout the body.^[2] It targets muscles and organs, in particular the brain.

Coffee beans

Caffeine is most commonly known for being in coffee.^[3] It is also found in tea, chocolate, soft drinks, energy drinks and medications.^[4]

The short term effects from caffeine are usually noticed after 5–30 minutes and long term ones last for up to 12 hours.^[4]

Those who use caffeine regularly, most often drinking at least one coffee a day, can become dependent and addicted.^[5] If caffeine use for these people is stopped they may have withdrawals symptoms of feeling tired and headaches.^[5]

Effects

Physical

Caffeine acts on both the respiratory system and cardiovascular system. The cardiovascular system is the pathway the human body uses for circulating blood, supplying oxygen and removing waste products.^[6] The respiratory system is the system involved with the exchange of oxygen and carbon dioxide between the atmosphere and the blood.^[7]

Via many of these physiological responses, the fatigue an athlete would normally feel is postponed, allowing physical activity to be sustained for longer and of a higher level.

 

Chemical structure of Caffeine Molecule

Cognitive

As caffeine targets the brain, there are many cognitive effects from using it.  Caffeine can reduce tiredness and reaction time.^[8]

Disadvantages

Physical

Caffeine is a mild diuretic, which can often lead to dehydration. Other physical disadvantages include, impaired fine motor control, observed via the shakiness of athlete's hands, gastrointestinal upset, increased heart rate and sleep disruptions.^[9]

Cognitive

Caffeine can cause feelings of anxiety and insomnia.^[8] Studies have found that sleep deprivation has a significant effect on sub-maximal, prolonged exercise.^[10] Caffeine also elevates stress hormone levels and one's perception of stress.^[11]

Effectiveness

Studies have found that typical doses of caffeine from 1–3 mg per kg of body weight will provide an effective improvement to performance. Previously, high doses were used such as 6 mg/kg, until recently lower doses supply the desired benefits with less consequences.^[12]

There is preliminary evidence that shows caffeine is effective for endurance and anaerobic activities.^[13]

Anaerobic athletes

 

Sprint athlete

In studies of trained males the discovery of the optimal amount of caffeine for anaerobic exercise was determined. A caffeine dosage of 3–5 mg/kg^[12] may improve high-intensity sprint performance when consumed prior to exercise.

One analysis showed that there were small improvements, in which they discussed for these activities correlate to meaningful differences in performance.^[14] The following conclusions were drawn:

• Caffeine ingested resulted in an increase in upper body strength but not lower body strength.
• For strength exercises, there was no significant differences between trained and untrained subjects
• Caffeine in capsule form had a greater influence on performance rather than liquid form, gums and gels were not tested.
• Using a vertical jump as an indicator of muscle power, results showed a significant increase in power, supporting caffeine as a possible ergogenic aid.^[14]

References

1. "Caffeine". Alcohol and Drug Foundation. 2019.
2. "What Is It About Coffee?". 2012.
3. "Coffee: Uses, Side Effects, Interactions, Dosage, and Warning". www.webmd.com. Retrieved 2019-05-28.
4. Services, Department of Health & Human. "Caffeine". www.betterhealth.vic.gov.au. Retrieved 2019-05-20.
5. "Caffeine". CAMH. Retrieved 2019-05-28.
6. Mooren, Frank (2012). Encyclopedia of Exercise Medicine in Health and Disease. Springer. ISBN 978-3-540-29807-6.{{cite book}}: CS1 maint: location missing publisher (link)
7. Gooch, Jan (2011). Encyclopedic Dictionary of Polymers. Springer. Bibcode:2011edop.book.....G. ISBN 978-1-4419-6247-8.{{cite book}}: CS1 maint: location missing publisher (link)
8. Wilson, Ted (2016). Beverage Impacts on Health and Nutrition. Humana Press. ISBN 978-3-319-23672-8.
9. Smith, A. (2002). "Effects of caffeine on human behavior". Food and Chemical Toxicology. 40 (9): 1243–1255. doi:10.1016/S0278-6915(02)00096-0. ISSN 0278-6915. PMID 12204388.
10. Halson, Shona (2013). "Sleep and The Elite Athlete". Sports Science Exchange. 26: 1–4. S2CID 7599812.
11. "The Benefits and Disadvantages of Caffeine". Brandon, FL Patch. 2014-06-18. Retrieved 2019-05-28.
12. "Sports Dietitians Australia". Retrieved 3 May 2010.
13. Collomp, K.; Ahmaidi, S.; Chatard, J. C.; Audran, M.; Préfaut, Ch. (1992-07-01). "Benefits of caffeine ingestion on sprint performance in trained and untrained swimmers". European Journal of Applied Physiology and Occupational Physiology. 64 (4): 377–380. doi:10.1007/BF00636227. ISSN 1439-6327. PMID 1592065. S2CID 20505531.
14. Grgic, Jozo; Trexler, Eric T.; Lazinica, Bruno; Pedisic, Zeljko (2018-03-05). "Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis". Journal of the International Society of Sports Nutrition. 15: 11. doi:10.1186/s12970-018-0216-0. ISSN 1550-2783. PMC 5839013. PMID 29527137.