16/07/2018
An epic post on Caffeine and it's benefits with exercise!
☕️Does caffeine improve exercise performance in everyone?
🏃🏼♂️Many studies have shown beneficial effects of caffeine on exercise performance (1), which led to the frequent use of caffeine by athletes. However, the individual responses to caffeine has been shown to vary a lot. Some individuals even appear to perform worse with caffeine (2).
🔎A possible explanation for these individual differences is the expression of the CYP1A2 gene. This enzyme metabolizes over 95% of caffeine (3). Individuals can be categorized in AA (fast metabolizers), AC (slow metabolizers), and CC (also slow metabolizers) based on their CYP1A2 genotype.
🚴♂️In the present study, subjects performed a 10-k cycling time trial 3 times with either 0, 2, or 4 mg/kg caffeine ingested ~75 min before. Fast metabolizers (AA genotype) improved their time trial performance by 7% with 4 mg/kg caffeine compared to placebo, while the slow metabolizers (CC genotype) decreased their time trial performance by 14%. No effect of caffeine was found in the slow metabolizers with the AC genotype.
😫In support, the rate of perceived effort was decreased in the fast metabolizers (AA genotype), while the slow metabolizers (CC genotype) showed no difference.
📊It should be noted that only 8% of the participants had the CC genotype and observed this negative effect of caffeine. 43% of the subjects had the AC genotype and observed no difference in performance, while the other 49% had the AA genotype which led to an improvement in performance.
💡In conclusion, although caffeine either improves or has no effect on performance in most people, it may actually decrease performance in some people.
📄Study by
https://www.ncbi.nlm.nih.gov/pubmed/29509641
🗂Other references:
1) https://www.ncbi.nlm.nih.gov/pubmed/19077738
2) https://www.ncbi.nlm.nih.gov/pubmed/25517202
3) https://www.ncbi.nlm.nih.gov/pubmed/17221922