Studies have shown that in endurance exercise (i.e. aerobic exercise in sports lasting more than five minutes, such as running, cycling and rowing), caffeine improves time-trial performance and can be associated with a reduction in muscle pain3-14. Research also suggests that caffeine can help during short-term, high-intensity (anaerobic) exercise, e.g. athletes performing high-intensity exercises and team sports15-23.
The European Food Safety Authority (EFSA) concluded that there is an association between caffeine consumption and an increase in endurance performance, endurance capacity and a reduction in the rated perceived effort or exertion during exercise24.
Caffeine is a major pharmacologically active compound in coffee, and many of the studies exploring its effect on sports performance are based on the supplementation of caffeine alone, rather than with coffee. While these provide a useful basis to explain the effects of coffee, it is possible that these findings may differ slightly than if the studies had been conducted using coffee.
Although much of the research has been undertaken in trained athletes, studies in sedentary people and those with lower levels of fitness also suggest that caffeine can improve performance in those who are not trained athletes25,26.
Caffeine may exert its effect through antagonism of the adenosine receptors in the brain – a pathway that leads to an increased production of adrenalin, which stimulates energy production and improves blood flow to the muscles and heart10,11. Caffeine may also modulate central fatigue, a type of fatigue caused by neurochemical changes in the brain associated with prolonged exercise, and in turn influence ratings of perceived exertion, perceived pain, and levels of vigour, all of which are likely to lead to improvements in performance11,12.
Fluid in the body is important: EFSA has concluded that a cause and effect relationship has been established between the dietary intake of water and the maintenance of normal and physical cognitive function27. Whilst there is some indication of a short-term diuretic effect of caffeine intake, this effect does not counter-balance the effects of the fluid intake from coffee drinking28-35. Drinking caffeinated coffee in moderation can therefore help maintain adequate fluid balance24-35.
The EFSA’s Scientific Opinion on the Safety of Caffeine concluded that ‘single doses of caffeine up to 200mg (about 3mg/kg bw) from all sources do not raise safety concerns for the general adult population, even if consumed less than two hours prior to intense physical exercise under normal environmental conditions36.
The content in this topic was last edited in July 2021. Papers in the Latest Research section and further resources are added regularly.