Influence of caffeine on perception of effort, metabolism and exercise performance following a high-fat meal

Abstract

This study examined the effects of caffeine, co-ingested with a high fat meal, on perceptual and metabolic responses during incremental (Experiment 1) and endurance (Experiment 2) exercise performance. Trained participants performed three constant-load cycling tests at approximately 73% of maximal oxygen uptake (VO2max) for 30 min at 20 degrees C (Experiment 1, n = 8) and to the limit of tolerance at 10 degrees C (Experiment 2, n = 10). The 30 min constant-load exercise in Experiment 1 was followed by incremental exercise (15 W . min-1) to fatigue. Four hours before the first test, the participants consumed a 90% carbohydrate meal (control trial); in the remaining two tests, the participants consumed a 90% fat meal with (fat + caffeine trial) and without (fat-only trial) caffeine. Caffeine and placebo were randomly assigned and ingested 1 h before exercise. In both experiments, ratings of perceived leg exertion were significantly lower during the fat + caffeine than fat-only trial (Experiment 1: P < 0.001; Experiment 2: P < 0.01). Ratings of perceived breathlessness were significantly lower in Experiment 1 (P < 0.01) and heart rate higher in Experiment 2 (P < 0.001) on the fat + caffeine than fat-only trial. In the two experiments, oxygen uptake, ventilation, blood [glucose], [lactate] and plasma [glycerol] were significantly higher on the fat + caffeine than fat-only trial. In Experiment 2, plasma [free fatty acids], blood [pyruvate] and the [lactate]:[pyruvate] ratio were significantly higher on the fat + caffeine than fat-only trial. Time to exhaustion during incremental exercise (Experiment 1: control: 4.9, s = 1.8 min; fat-only: 5.0, s = 2.2 min; fat + caffeine: 5.0, s = 2.2 min; P > 0.05) and constant-load exercise (Experiment 2: control: 116 (88 - 145) min; fat-only: 122 (96 - 144) min; fat + caffeine: 127 (107 - 176) min; P > 0.05) was not different between the fat-only and fat + caffeine trials. In conclusion, while a number of metabolic responses were increased during exercise after caffeine ingestion, perception of effort was reduced and this may be attributed to the direct stimulatory effect of caffeine on the central nervous system. However, this caffeine-induced reduction in effort perception did not improve exercise performance.

Metabolic effects of a caffeinated sports drink consumed during a soccer match

“…In this study, athletes presented higher values of glycemia with the ingestion of the CSD compared to the CCD, thus agreeing with the results obtained in other studies (Hadjicharalambous et al, 2006;Woolf, Bidwell, & Carlson, 2008), suggesting a lower glucose utilization during exercise in athletes consuming caffeine. Another proposed mechanism is the increase of sympathetic nervous system activity by caffeine, which promotes secretion of adrenaline and noradrenaline (Davis et al, 2003;Yeo, Jentjens, Wallis, & Jeukendrup, 2005).…”

“…These studies have shown that during exercise, caffeine acts on blood glycemia, increasing its concentration in both aerobic (Hadjicharalambous, Georgiades, Kilduff, Turner, Tsofliou, Pitsiladis et al, 2006) and anaerobic exercise (Woolf, Bidwell & Carlson, 2008). Other researchers have also shown that caffeine tends of promote an increase in plasma lactate (Carr, Dawson, Schneiker, Goodman, & Lay, 2008) (Bassini-Cameron, Sweet, Bottino, Bittar, Veiga et al, 2007) and FFA (McNaughton et al, 2008), while K + generally suffers a decrease after its ingestion (Simmonds, Minahan, & Sabapathy et al, 2010).…”

Nonexercise movement in elderly compared with young people

“…Changes in, or dysregulation of, central mechanisms that modulate or regulate activity may occur with aging (14,41,45). Alternatively, there may be a change in the central perception of fatigue, resulting in a lower threshold for activity cessation (2,12,31,42). There may be dysfunction or dysregulation in peripheral neurons or intrinsic muscle function limiting the activity that a subject may be able to perform.…”

“…BMR was measured on three consecutive mornings (days 12,13,14) between 0600 and 0800 in the subjects who had slept uninterrupted the previous nights in the GCRC (subjects were admitted to the GCRC on the evening of day 11). Subjects were not moved prior to measurements and had not eaten since 2100 the night before.…”

Risks of Alcoholic Energy Drinks for Youth

“…1,2 It gives the perception of decreased intoxication without altering impairment. 1,3,4 Previously a do-it-yourself activity by college students, 5 entrepreneurs made it easier for underage individuals by producing premixed drinks, such as Rock Star 21, Joose, 6 and Steel Reserve, 6 -9 usually by adding vodka, with an alcohol content of 6% to 9.9%, and caffeine (80 to 400 mg) to the energy drink. 6 -9 When asked to speak on this topic to a parents' group, I was uneducated.…”