Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2013 Aug 19;8(8):e72025.
doi: 10.1371/journal.pone.0072025. eCollection 2013.

Caffeine Increases Anaerobic Work and Restores Cycling Performance Following a Protocol Designed to Lower Endogenous Carbohydrate Availability

Affiliations
Free PMC article
Randomized Controlled Trial

Caffeine Increases Anaerobic Work and Restores Cycling Performance Following a Protocol Designed to Lower Endogenous Carbohydrate Availability

Marcos David Silva-Cavalcante et al. PLoS One. .
Free PMC article

Abstract

The purpose this study was to examine the effects of caffeine ingestion on performance and energy expenditure (anaerobic and aerobic contribution) during a 4-km cycling time trial (TT) performed after a carbohydrate (CHO) availability-lowering exercise protocol. After preliminary and familiarization trials, seven amateur cyclists performed three 4-km cycling TT in a double-blind, randomized and crossover design. The trials were performed either after no previous exercise (CON), or after a CHO availability-lowering exercise protocol (DEP) performed in the previous evening, followed by either placebo (DEP-PLA) or 5 mg.kg(-1) of caffeine intake (DEP-CAF) 1 hour before the trial. Performance was reduced (-2.1%) in DEP-PLA vs CON (421.0±12.3 vs 412.4±9.7 s). However, performance was restored in DEP-CAF (404.6±17.1 s) compared with DEP-PLA, while no differences were found between DEP-CAF and CON. The anaerobic contribution was increased in DEP-CAF compared with both DEP-PLA and CON (67.4±14.91, 47. 3±14.6 and 55.3±14.0 W, respectively), and this was more pronounced in the first 3 km of the trial. Similarly, total anaerobic work was higher in DEP-CAF than in the other conditions. The integrated electromyographic activity, plasma lactate concentration, oxygen uptake, aerobic contribution and total aerobic work were not different between the conditions. The reduction in performance associated with low CHO availability is reversed with caffeine ingestion due to a higher anaerobic contribution, suggesting that caffeine could access an anaerobic "reserve" that is not used under normal conditions.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Experimental Protocol.
[La]: plasma lactate concentrations; MVC: maximal voluntary contraction; EMG: electromyographic activity; VO2: oxygen uptake; RER: respiratory exchange ratio; HR: heart rate; PPO: power output; Paer: aerobic mechanical power output; Pan: anaerobic mechanical power output.
Figure 2
Figure 2. Time to complete the 4-km cycling TT for control (CON), low carbohydrate availability with placebo ingestion (DEP-PLA) and low carbohydrate availability with caffeine ingestion (DEP-CAF).
*Moderate effect of DEP-PLA compared to CON and DEP-CAF (ES = 0.65 and 0.94, respectively). #Small effect of DEP-CAF compared to CON (ES = 0.45). Data are expressed as mean (•) and individual (○) values.
Figure 3
Figure 3. Mean and SD for work total (Wtot), total aerobic (Waer) and anaerobic work (Wan) during the 4-km cycling TT for control (CON), low carbohydrate availability with placebo ingestion (DEP-PLA) and low carbohydrate availability with caffeine ingestion (DEP-CAF).
*Moderate effect of DEP-PLA compared to CON (ES = 0.93). §Small and moderate effect of DEP-CAF compared to CON and DEP-PLA (ES = 0.53 and 1.18, respectively). †Small effect of DEP-PLA compared to CON (ES = 0.40). #Moderate and large effects of DEP-CAF compared to CON and DEP-PLA (ES = 0.96 and 1.33, respectively).
Figure 4
Figure 4. Mean and SD for power output (upper), anaerobic (middle) and aerobic (lower) mechanic power for each 200 m during the 4-km cycling TT for control (CON), low carbohydrate availability with placebo ingestion (DEP-PLA) and low carbohydrate availability with caffeine ingestion (DEP-CAF).
*Significantly different between DEP-CAF and DEP-PLA (P<0.05); #Significantly different between CON and DEP-PLA (P<0.05); †Significantly different between DEP-CAF and CON (P<0.05).

Similar articles

See all similar articles

Cited by 11 articles

See all "Cited by" articles

References

    1. Greenhaff PL, Gleeson M, Maughan RJ (1987) The effects of dietary manipulation on blood acid-base status and the performance of high intensity exercise. Eur J Appl Physiol Occup Physiol 56: 331–337. - PubMed
    1. Langfort J, Zarzeczny R, Pilis W, Nazar K, Kaciuba-Uscitko H (1997) The effect of a low-carbohydrate diet on performance, hormonal and metabolic responses to a 30-s bout of supramaximal exercise. Eur J Appl Physiol 76: 128–133. - PubMed
    1. Lima-Silva AE, Pires FO, Bertuzzi RC, Lira FS, Casarini D, et al. (2011) Low carbohydrate diet affects the oxygen uptake on-kinetics and rating of perceived exertion in high intensity exercise. Psychophysiology 48: 277–284. - PubMed
    1. Maughan RJ, Poole DC (1981) The effects of a glycogen-loading regimen on the capacity to perform anaerobic exercise. Eur J Appl Physiol 46: 211–219. - PubMed
    1. Miura A, Sato H, Sato H, Whipp BJ, Fukuba Y (2000) The effect of glycogen depletion on the curvature constant parameter of the power-duration curve for cycle ergometry. Ergonomics 43: 133–141. - PubMed

Publication types

Grant support

This project was supported by Coordination of Improvement of Personnel of Superior Level (CAPES-PRODOC, MEC/CAPES 29/2010). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Feedback