Real and Perceived Effects of Caffeine on Sprint Cycling in Experienced Cyclists.

Anderson, DE, German, RE, Harrison, ME, Bourassa, KN, and Taylor, CE. Real and perceived effects of caffeine on sprint cycling in experienced cyclists. J Strength Cond Res 34(4): 929-933, 2020-Caffeine ingestion before an exercise bout may provide ergogenic effects on anaerobic performance, particularly in trained athletes. However, the degree of influence of caffeine may be coupled with the placebo effect. A double-blind, placebo-controlled, randomized design was used to determine the real and perceived effects of caffeine on anaerobic performance. Ten competitively trained cyclists (9 men and 1 woman) completed 3 trials of the Wingate Anaerobic Test (WAnT). Subjects were given coffee that they believed contained a high caffeine dose, a low caffeine dose, or a placebo 45 minutes before WAnT. Subjects were actually given 2 placebos (decaffeinated coffee) and one dose of caffeine (280 mg). Level of significance was p ≤ 0.05. No significant differences were found between trials for blood lactate concentration and heart rate. Seven of the subjects (70%) correctly identified the caffeine trial as the high caffeine trial. Time to peak power was significantly shorter for the trial in which subjects incorrectly guessed they had consumed caffeine when given the placebo compared with placebo trial (1.6 ± 0.1 vs. 2.3 ± 0.2 seconds). Power drop was significantly higher for the trial in which subjects incorrectly guessed they had consumed caffeine when given the placebo compared with placebo trial (524 ± 37 vs. 433 ± 35 W). There seems to be a placebo effect of caffeine on anaerobic performance. Improved performance may result from psychological advantages rather than physical advantages. Coaches may find it beneficial to use a placebo to improve anaerobic performance, especially if concerned about the side effects or cost of caffeine.

Effect of Caffeine on Sprint Cycling in Experienced Cyclists.

Anderson, DE, LeGrand, SE, and McCart, RD. Effect of caffeine on sprint cycling in experienced cyclists. J Strength Cond Res 32(8): 2221-2226, 2018-Research regarding the ergogenic effects of caffeine (CAF) in anaerobic activity remains inconclusive. However, some researchers have found significant improvements in anaerobic performance when testing specifically trained athletes. A double-blind, placebo-controlled, counterbalanced, cross-over design was implemented to assess the impact of CAF on a 30-second Wingate Anaerobic Test (WAnT) in experienced cyclists. Nine experienced cyclists volunteered to participate in this study (men, n = 7 and women, n = 2). The subjects completed 2 separate experimental trials consisting of a 30-second WAnT at a resistance of 9% body mass. In a random order, 1 hour before each WAnT, subjects ingested either a CAF (∼280 mg) or placebo (PLAC) coffee. For each trial, heart rate (HR) and blood lactate (BL) values were recorded at rest, pre-WAnT, post-WAnT, and 5 minutes post-WAnT. After each trial, the subjects recorded their perception of which treatment they received. Heart rate and BL responses were not significantly different between the CAF and PLAC conditions. The ingestion of CAF did not significantly improve peak anaerobic power, mean anaerobic power, nor fatigue index. In at least 1 of the 2 trials, 44% of the subjects incorrectly guessed which substance they had ingested. The findings of this study do not show a significant correlation between CAF ingestion and improved anaerobic performance in experienced cyclists. However, performance enhancements may depend on varying individual responses to CAF. Athletes who are positive CAF responders may consider using coffee before competition to improve anaerobic performance.

International society of sports nutrition position stand: coffee and sports performance.

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).

The impact of feedback on dietary intake and body composition of college women volleyball players over a competitive season.

The purpose of this study was to examine the impact of nutritional feedback on dietary intake and body composition of college women volleyball players. Eight members of an National Collegiate Athletic Association (NCAA) division II women's volleyball team participated as subjects. Three-day diet records and body composition (via air displacement plethysmography) were analyzed at the beginning of the season (Beginning), peak training during the season (Peak), and 1 week postseason (After). During the first season (Baseline), the athletes were given no information concerning their dietary intakes. In the following year (Feedback), athletes were given information with regard to dietary intakes of themselves and the team as a whole. Percent body fat was not significantly different between Baseline and Feedback trials. During Beginning and Peak, the mean energy intakes ranged from 35.3 to 40.8 kcal.kg.bw. Protein intake was significantly greater in Feedback-Beginning (1.5 +/- 0.9 gxkgxbw) compared to Baseline-Beginning (1.1 +/- 0.1 gxkgxbw). No significant differences were seen in Baseline vs. Feedback for either carbohydrate or fat intakes. The only vitamin with significantly different consumption was vitamin C, with intakes of Feedback-Beginning (303.8 +/- 99.8% Dietary Reference Intakes [DRI]) vs. Baseline-Beginning (115.3 +/- 32.3% DRI). A significantly greater amount of calcium was consumed at Feedback-Beginning (152.0 +/- 25.2% DRI) compared to Baseline-Beginning (102.2 +/- 21.2% DRI). In conclusion, dietary feedback resulted in increased intake of protein, vitamin C, and calcium at the beginning of the season only for female collegiate volleyball players. Other than an increase in fiber, dietary intake at the peak of the season and postseason was not influenced by feedback. Body composition was unaffected by feedback at Beginning, Peak, and After.

Reliability of air displacement plethysmography.

The purpose of this study was to examine the reliability of an air displacement plethysmography device (BOD POD) over trials performed on 3 different days. Subjects consisted of 24 healthy adults (8 men, 16 women), ages 18-38 years, with body weights 46.8-93.6 kg, body mass indexes of 19.1-30.1 kg x m(-2), and percentage body fats (BF) of 7.9-43.1%. Two estimates of BF were performed on 3 days. Paired t-tests revealed no significant within-day differences in body volume (BV), thoracic gas volume (V(TG)), body density (BD), and BF. Correlations between the two V(TG) measures on a day were r = 0.86 for day 1, r = 0.93 for day 2, and r = 0.96 for day 3. BF estimates within a day had high correlations of r = 0.98. Significant differences were found between days for measures of BV, V(TG), BD, and BF. These results indicate a high reliability for within-day estimates of BF and significant differences in between-day estimates of BF using air displacement plethysmography. Reliability of BF may be increased by requiring subjects to practice the procedure for V(TG) measurement.