PURPOSE: 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, crossover study design was employed (N=13). All participants completed 1 familiarization trial followed by 2 experimental rowing time trials. The experimental trials were performed 10 min 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 (VO2), carbon dioxide production, minute ventilation (VE), 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 pairedsamples t test identified a significant improvement in 2000-m performance of 5.2±3.9 s (1.1%±1.7%; P=.034). Two-way repeated-measures ANOVA revealed no significant treatment effect for HR (177±8 vs 177±9 beats/min, P=.817), VO2 (46.1±6.5 vs 46.6±6.2 mL·kg(-1)·min(-1), P=.590), VE (121.8±14.7 vs 124.8±15.7 L/min, P=.490), RPE, GI, or Thirst for CP and CC, respectively. Paired-samples t tests revealed no treatment effect for postexercise [La-] between CP and CC (11.72±2.69 vs 12.26±3.13 mmol/L, P=.534). CONCLUSION: A relatively low dose of caffeine (1.3±0.1 mg/kg body mass) in an isotonic carbohydrate gel ingested only 10 min before performance improved 2000-m rowing time by 5.2±7.8 s (1.1%±1.7%).
RCT Entities:
PURPOSE: 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, crossover study design was employed (N=13). All participants completed 1 familiarization trial followed by 2 experimental rowing time trials. The experimental trials were performed 10 min 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 (VO2), carbon dioxide production, minute ventilation (VE), 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 pairedsamples t test identified a significant improvement in 2000-m performance of 5.2±3.9 s (1.1%±1.7%; P=.034). Two-way repeated-measures ANOVA revealed no significant treatment effect for HR (177±8 vs 177±9 beats/min, P=.817), VO2 (46.1±6.5 vs 46.6±6.2 mL·kg(-1)·min(-1), P=.590), VE (121.8±14.7 vs 124.8±15.7 L/min, P=.490), RPE, GI, or Thirst for CP and CC, respectively. Paired-samples t tests revealed no treatment effect for postexercise [La-] between CP and CC (11.72±2.69 vs 12.26±3.13 mmol/L, P=.534). CONCLUSION: A relatively low dose of caffeine (1.3±0.1 mg/kg body mass) in an isotonic carbohydrate gel ingested only 10 min before performance improved 2000-m rowing time by 5.2±7.8 s (1.1%±1.7%).
Authors: Nanci S Guest; Trisha A VanDusseldorp; Michael T Nelson; Jozo Grgic; Brad J Schoenfeld; Nathaniel D M Jenkins; Shawn M Arent; Jose Antonio; Jeffrey R Stout; Eric T Trexler; Abbie E Smith-Ryan; Erica R Goldstein; Douglas S Kalman; Bill I Campbell Journal: J Int Soc Sports Nutr Date: 2021-01-02 Impact factor: 5.150
Authors: Anthony Zulli; Renee M Smith; Peter Kubatka; Jan Novak; Yoshio Uehara; Hayley Loftus; Tawar Qaradakhi; Miroslav Pohanka; Nazarii Kobyliak; Angela Zagatina; Jan Klimas; Alan Hayes; Giampiero La Rocca; Miroslav Soucek; Peter Kruzliak Journal: Eur J Nutr Date: 2016-03-01 Impact factor: 5.614
Authors: Jozo Grgic; Francisco Javier Diaz-Lara; Juan Del Coso; Michael J Duncan; Jason Tallis; Craig Pickering; Brad J Schoenfeld; Pavle Mikulic Journal: Nutrients Date: 2020-02-08 Impact factor: 5.717