Coffee Consumption for Physical Performance. Caffeine’s influence on endurance and exercise capacity is of interest to athletes. Caffeine has been shown to improve endurance events, stop-go events (such as team and racket sports), and sports involving prolonged high-intensity action ranging from 1 minute to an hour (such as swimming, rowing, and running races) (Goldstein et al., 2010). (Fig. 20.2).
For instance, when 3 mg caffeine/kg bodyweight was consumed instead of a placebo, work done during a 15-minute time trial on stationary bikes rose by 4%. (Jenkins et al., 2008).
Caffeine’s active dose has been determined to be 3 mg/kg of body weight, taken 1 hour before activity, based on comprehensive scientific investigations (EFSA 2053, 2011a; Goldstein et al., 2010). This amount would be similar to 210 milligrams for a person weighing around 70 kg.
Athletes have long utilized coffee and other caffeine-containing beverages, and the first publications detailing the mechanisms were published in 1978 (Costill et al., 1977).
Caffeine not only improves attention and alertness, as well as concentration (Hogervost et al., 2008), coordination (Hogervost et al., 2008), and pain and tiredness perception (O’Connor, 2004; Gliottoni and Motl, 2008; Gliottoni et al., 2009). Caffeine, when given a few hours before reaching a high altitude, may also help to prevent acute mountain sickness (Kamimori et al., 1995).
Caffeine’s many mechanisms of action for physical performance have been thoroughly researched and are well understood. Caffeine, for starters, competes with adenosine for receptor sites (Fredholm et al., 1999; Spriet and Gibala, 2004).
Caffeine raises adrenaline and dopamine levels, which are part of the body’s “fight or flight” reaction, and prepares the body for physical activity by increasing heart rate and blood pressure (Jackmann et al., 1996; Greer et al., 1998). Caffeine’s ability to stimulate the release of b-endorphins is most likely responsible for the reduction in pain perception.
This impact could be due to the analgesic effects of these chemicals (O’Connor et al., 2004; Gliottoni and Motl, 2008; Gliottoni et al., 2009). Even if the perceived effect of coffee on athletic performance is muscular, the mechanisms that cause it are neural (Spriet, 1995).
Athletes can safely ingest up to 400 mg of caffeine per day, according to the EFSA caffeine safety report (EFSA 4102, 2015a), which is the same threshold as adults. Furthermore, it is safe to consume single doses of 200 mg of caffeine less than 2 hours prior to intense exercise in normal environmental conditions, but the amount and time prior to exercise will vary for different individuals because, as previously stated, they may metabolize caffeine at different rates.
The International Olympic Committee created an antidoping policy in 1984 that includes caffeine with a serum threshold of 12 mg/mL because of caffeine’s intrinsic performance-enhancing qualities. Only a caffeine intake of roughly 9 mg/kg would result in this amount. Because performance gains can be obtained with merely 3 mg of caffeine/kg of body weight, such a threshold is debatable.
Furthermore, it is extremely difficult to measure caffeine serum levels due to individual variances in their ability to metabolize caffeine over time (Goldstein et al., 2010). This debate, as well as the inefficiency of the threshold for distinguishing between social and deliberate use of caffeine to improve performance, were two of the reasons why the World Anti-Doping Agency (WADA) withdrew caffeine from the forbidden list and added it to its monitoring program in 2004. (WADA, 2009). The monitoring program includes chemicals that aren’t banned in sports but that WADA looks into to see if there are any abuse trends.
Athletes can benefit from the high level of polyphenols (chlorogenic acids), as well as the mineral content, in addition to caffeine. It is well understood that vigorous exercise increases oxygen consumption, increases reactive oxygen species production, promotes lipid peroxidation of polyunsaturated fatty acids in membranes and DNA damage, and reduces physical performance. Exercise-induced oxidative stress may be exacerbated by the release of inflammatory cytokines, as evidenced by other dietary products (Chang et al., 2010).
Athletes can benefit from the high level of polyphenols (chlorogenic acids), as well as the mineral content, in addition to caffeine. It is well understood that vigorous exercise increases oxygen consumption, increases reactive oxygen species production, promotes lipid peroxidation of polyunsaturated fatty acids in membranes and DNA damage, and reduces physical performance.
Exercise-induced oxidative stress may be exacerbated by the release of inflammatory cytokines, as evidenced by other dietary products (Chang et al., 2010). A number of studies have found that drinking polyphenol-rich beverages, such as chlorogenic acids, before or after intense exercise reduced plasma levels of oxidative and inflammation markers, protecting against exercise-induced oxidative damage and reducing inflammation (Chang et al., 2010; Panza et al., 2008).