Abstract
Purpose - The aim of this study was to investigate the effect of ingesting a caffeinated carbohydrate gel (CC) 10 minutes prior on 2000 m rowing performance compared with a carbohydrate-only placebo gel (CP).
Methods - A counterbalanced, single-blind, cross-over study was employed (n=13). All participants completed one familiarisation trial followed by two experimental time trials (TT). The experimental trials were performed 10 minutes after ingesting CP (21.6 g of carbohydrate, 0 mg caffeine) or CC (21.6 g carbohydrate, 100 mg caffeine), and heart rate (HR), oxygen consumption (V̇O2), carbon dioxide production (V̇CO2), minute ventilation (V̇E), respiratory exchange ratio (RER), rating of perceived exertion (RPE), gastrointestinal discomfort (GI) and thirst perception (Thirst) were recorded every 200 m. Blood lactate [La-] was recorded immediately before and after exercise.
Results - A paired samples t-test identified a significant improvement in 2000 m performance of 5.2 ± 3.9 s (1.1 ± 1.7%; p=0.034). Two-way repeated-measures ANOVA revealed no significant treatment effect for HR (177 ± 8 b•min-1 vs 177 ± 9 b•min-1; p=0.817), V̇O2 (46.1 ± 6.5 ml•kg•min-1 vs 46.6 ± 6.2 ml•kg•min-1; p=0.590), V̇E (121.8 ± 14.7 L•min-1 vs 124.8 ± 15.7 L•min-1; p=0.490), or for RPE, GI) or Thirst for CP and CC, respectively. Paired samples t-tests revealed no treatment effect for post-exercise [La-] between CP and CC (11.72 ± 2.69 mmol•L-1 vs 12.26 ± 3.13 mmol•L-1; p=0.534). Conclusion A relatively low dose of caffeine (1.3 ± 0.1 mg•kg-1BM) in an isotonic CHO gel ingested only 10 minutes prior to performance, improved 2000 m rowing time by 5.2 ± 7.8 s (1.1 ± 1.7%).
Methods - A counterbalanced, single-blind, cross-over study was employed (n=13). All participants completed one familiarisation trial followed by two experimental time trials (TT). The experimental trials were performed 10 minutes after ingesting CP (21.6 g of carbohydrate, 0 mg caffeine) or CC (21.6 g carbohydrate, 100 mg caffeine), and heart rate (HR), oxygen consumption (V̇O2), carbon dioxide production (V̇CO2), minute ventilation (V̇E), respiratory exchange ratio (RER), rating of perceived exertion (RPE), gastrointestinal discomfort (GI) and thirst perception (Thirst) were recorded every 200 m. Blood lactate [La-] was recorded immediately before and after exercise.
Results - A paired samples t-test identified a significant improvement in 2000 m performance of 5.2 ± 3.9 s (1.1 ± 1.7%; p=0.034). Two-way repeated-measures ANOVA revealed no significant treatment effect for HR (177 ± 8 b•min-1 vs 177 ± 9 b•min-1; p=0.817), V̇O2 (46.1 ± 6.5 ml•kg•min-1 vs 46.6 ± 6.2 ml•kg•min-1; p=0.590), V̇E (121.8 ± 14.7 L•min-1 vs 124.8 ± 15.7 L•min-1; p=0.490), or for RPE, GI) or Thirst for CP and CC, respectively. Paired samples t-tests revealed no treatment effect for post-exercise [La-] between CP and CC (11.72 ± 2.69 mmol•L-1 vs 12.26 ± 3.13 mmol•L-1; p=0.534). Conclusion A relatively low dose of caffeine (1.3 ± 0.1 mg•kg-1BM) in an isotonic CHO gel ingested only 10 minutes prior to performance, improved 2000 m rowing time by 5.2 ± 7.8 s (1.1 ± 1.7%).
| Original language | English |
|---|---|
| Pages (from-to) | 464-468 |
| Journal | International Journal of Sports Physiology and Performance |
| Volume | 10 |
| Issue number | 4 |
| Early online date | 29 Oct 2014 |
| DOIs | |
| Publication status | Published - May 2015 |
Keywords
- Caffeine
- Isotonic gel
- High intensity
- Time trial