Caffeine Ingestion Does Not Alter Performance during a 100-km Cycling Time-Trial Performance

Abstract

This study analyzed the effect of caffeine ingestion on performance during a repeated-measures, 100-km, laboratory cycling time trial that included bouts of 1-and 4-km high intensity epochs (HIE). Eight highly trained cyclists participated in 3 separate trials-placebo ingestion before exercise with a placebo carbohydrate solution and placebo tablets during exercise (Pl), or placebo ingestion before exercise with a 7% carbohydrate drink and placebo tablets during exercise (Cho), or caffeine tablet ingestion before and during exercise with 7% carbohydrate (Caf). Placebo (twice) or 6 mg · kg -1 caffeine was ingested 60 min prior to starting 1 of the 3 cycling trials, during which subjects ingested either additional placebos or a caffeine maintenance dose of 0.33 mg · kg -1 every 15 min to trial completion. The 100-km time trial consisted of five 1-km HIE after 10, 32, 52, 72, and 99 km, as well as four 4-km HIE after 20, 40, 60, and 80 km. Subjects were instructed to complete the time trial and all HIE as fast as possible. Plasma (caffeine) was significantly higher during Caf (0.43 ± 0.56 and 1.11 ± 1.78 mM pre vs. post Pl; and 47.32 ± 12.01 and 72.43 ± 29.08 mM pre vs. post Caf). Average power, HIE time to completion, and 100-km time to completion were not different between trials. Mean heart rates during both the 1-km HIE (184.0 ± 9.8 Caf; 177.0 ± 5.8 Pl; 177.4 ± 8.9 Cho) and 4-km HIE (181.7 ± 5.7 Caf; 174.3 ± 7.2 Pl; 175.6 ± 7.6 Cho; p < .05) was higher in Caf than in the other groups. No significant differences were found between groups for either EMG amplitude (IEMG) or mean power frequency spectrum (MPFS). IEMG activity and performance were not different between groups but were both higher in the 1-km HIE, indicating the absence of peripheral fatigue and the presence of a centrally-regulated pacing strategy that is not altered by caffeine ingestion. Caffeine may be without ergogenic benefit during endurance exercise in which the athlete begins exercise with a defined, predetermined goal measured as speed or distance.

Effects Of Dietary Nitrate, Caffeine, And Their Combination On 20 Km Cycling Time-trial Performance

“…Moreover, the effect of caffeine supplementation on time-trial performance adds to the considerable body of previous research supporting a positive effect of caffeine on endurance exercise (10,20). Although research into the effects of caffeine on time-trial performance, particularly in well-trained athletes, is less substantive; it generally, but not always (14,22) corroborates the results of the present study (8,9,32,39,42).…”

Does Caffeine Added to Carbohydrate Provide Additional Ergogenic Benefit for Endurance?

“…After reviewing the articles, 121 were eliminated as not meeting the inclusion criteria (e.g., an endurance performance task of at least 10 min and comparing both CHO and CHO+CAF conditions). Nineteen studies met the inclusion criteria (Table 1): thirteen peer-reviewed research articles Cox et al, 2002;Cureton et al, 2007;Hogervorst et al, 2008;Hulston & Jeukendrup, 2008;Hunter et al, 2002;Jacobson et al, 2001;Kovacs et al, 1998;Sasaki et al, 1987;Slivka et al, 2008;van Nieuwenhoven et al, 2005), five published abstracts from conference proceedings (Eschbach et al, 2002;Ganio et al, 2007;King et al, 2006;Rehrer et al, 1997;Smith et al, 2006), and one unpublished master's thesis (MacLeod, 2004). We included these well-designed scientific abstracts and thesis despite their tendency to influence the results toward a null finding.…”

“…Subjects in four studies did not consume the CHO and CAF at the same time points: CAF was consumed either 3 hr before beginning exercise (Eschbach et al, 2002), 1 hr before beginning exercise (Rehrer et al, 1997), or 1 hr before and during exercise (Cox Studies A and B;Cox et al, 2002). The CAF was ingested in the form of a capsule Cox et al, 2002;Eschbach et al, 2002;Hunter et al, 2002;Jacobson et al, 2001;Rehrer et al, 1997;Slivka et al, 2008), dissolved in a drink (Cureton et al, 2007;Ganio et al, 2007;Hulston & Jeukendrup, 2008;King et al, 2006;Kovacs et al, 1998;MacLeod, 2004;Sasaki et al, 1987;van Nieuwenhoven et al, 2005), or contained in a performance bar (Hogervorst et al, 2008). Only three studies used a CHO condition that contained only CHO (plus flavoring; MacLeod, 2004;Rehrer et al, 1997;Sasaki et al, 1987).…”

“…Some studies report significant performance improvements with CHO+CAF (Cox et al, 2002;Cureton et al, 2007;Kovacs et al, 1998), and others demonstrated no additional benefit (Hunter, St. Clair Gibson, Collins, Lambert, & Noakes, 2002;Sasaki, Maeda, Usui, & Ishiko, 1987;van Nieuwenhoven, Brouns, & Kovacs, 2005) beyond ingestion of CHO alone. The reason for equivocal results is unclear but might be the variety of experimental factors across the studies, such as subject characteristics, caffeine dose, or the test selected to evaluate exercise performance.…”

Caffeine Use in Sports: Considerations for the Athlete

“…Combining caffeine with nutritional supplements and other ergogenic compounds has recently become popular with the general public and in the scientific research community. Caffeine coingested with a carbohydrate (CHO) solution has been shown to have no additive effects on substrate use and exercise performance in 3 studies (32,37,62). However, caffeine has also been shown to improve 1-hour time trial cycling performance in a dose-dependent manner, when added to a 7% CHO-electrolyte drink, without having any effects on fat oxidation (39).…”