This study examined the effects of a d-β-hydroxybutyrate (βHB) containing beverage on cognitive and performance measures during a bout of repeated Wingates. Fifteen healthy, college-aged males (mean ± SD; age: 23.1 ± 2.4 years, height: 165.4 ± 2.0 cm, mass: 81.4 ± 9.2 kg) volunteered for the present study. Trial 1 consisted of baseline measures and familiarization for the protocol. During trials 2 and 3, subjects reported to the laboratory, after a 10-h fast, and ingested 11.38 g of βHB or a placebo (PLA) beverage 30 min before exercise. Participants then completed a cognitive challenge (CC), consisting of a 5-min FitLight response task while cycling. At the cessation of the test, participants then completed four 15-s repeated Wingates with 4 min of rest between, followed by another 5-min CC response task. Blood ketones, glucose, and lactate were measured pre-CC and post-Wingates. βHB levels were significantly higher compared with PLA (0.53 vs. 0.21 mmol/L), respectively. A significant order effect was observed across trials 2 and 3 for total FitLight misses and hits, regardless of treatment. Further, there were no significant differences among Wingate power output between treatments, although fatigue index was higher in the βHB group compared with PLA (32.3 vs. 29.4 W/s), respectively. In conclusion, βHB did not improve high-intensity cycling or cognitive performance measures; however, these findings might be partially explained by the absolute dosing protocol used for βHB in the present study as opposed to a relative (g/kg) dosing protocol used in previous research.

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BackgroundCarbohydrate (CHO) supplementation during endurance exercises has been shown to increase performance, but there is limited research with CHO supplementation during strength and conditioning exercises. Therefore, the purpose of this study was to examine the effects of various levels of CHO ingestion during acute testing sessions requiring participants to complete a strength and conditioning program designed for collegiate athletes.MethodsParticipants (n = 7) performed a series of exercises while ingesting an amino-acid electrolyte control (CON) or CON plus varying levels of CHO. The CHO beverages delivered a 2:1 (glucose: fructose) ratio at rates of 15 g/h, 30 g/h, and 60 g/h. The exercise protocol consisted of a series of short sprints, full body resistance training exercises, jumping, and shuttle running. Performance measurements were taken for sprint times, repetitions until failure [bench press, bent over row, biceps curl, overhead triceps extension], summation of total repetitions for all repetitions until failure, repetitions in a set time for two-foot line jumps, and 137-m shuttle times.ResultsA significant main effect (p < 0.05) was found in relation to CHO dose during the bench press final set repetitions to failure. Pairwise comparison with Bonferroni’s correction identified that there was significant difference (p = 0.0024) between the dosage of 15 g/h and CON during bench press. Inferential statistics identified overall RT performance with a dosage of 15 g/h compared to 60 g/h and CON was 99.2 % (very likely) and 96.7 % (very likely) to have a beneficial effect.ConclusionsThe results from this study suggest acute ingestion of CHO does not result in decrements in performance and may provide a beneficial effect to strength and conditioning performance. Strength and conditioning coaches may recommend their athletes ingest CHO during training sessions in order to maximize muscular adaptations.

The purpose of this investigation was to examine to the influence of carbohydrate ingestion (CHOI) and carbohydrate mouth rinse (CHOR) on acute repeat maximal sprint performance. Fourteen healthy males (age: 21.7 ± 1.8 years, mass: 82.3 ± 12.3 kg) completed a total of five 15-s maximal repeat sprints on a cycle ergometer against 0.075 kg ・ kg body mass each separated by 4 min of active recovery. Subjects completed four experimental trials and were randomly assigned one of four treatments: (1) CHOI, (2) CHOR, (3) placebo mouth rinse (PLAR), (4) placebo ingestion (PLAI). Subjects rinsed or ingested six 50 mL 10% CHO solutions throughout each trial. Performance variables measured included rating of perceived exertion, peak heart rate, peak and mean power output, fatigue index, and total work. Significant treatment main effects were observed for mean power output (p = 0.026), total work (p = 0.020), fatigue index (p = 0.004), and heart rate (p = 0.013). Overall mean power output and total work were significantly greater with CHOI (659.3 ± 103.0 watts, 9849.8 ± 1598.8 joules) compared with CHOR (645.8 ± 99.7 watts, 9447.5 ± 1684.9 joules, p < .05). CHOI (15.3 ± 8.6 watts/s) significantly attenuated fatigue index compared with CHOR (17.7 ± 10.4 watts/s, p < .05). Based on our findings, CHOI was more likely to provide a beneficial performance effect compared with CHOR, PLAI, and PLAR. Athletes required to complete repeat bouts of high intensity exercise may benefit from CHOI.

The purpose of this investigation was to examine the individual and combined effects of ingesting carbohydrates (CHO) and branched-chain amino acids (BCAA) during high-volume upper body resistance exercise (RE) on markers of catabolism and performance. Thirteen resistance-trained males completed 4 experimental trials with supplementation, ingesting beverages containing CHO, BCAA, CHO+BCAA, or placebo (PLA) in a randomized, double-blind design. The beverages were ingested in 118-mL servings 6 times during an ∼60-min RE session consisting of bench press, bent-over row, incline press, and close-grip row. Each RE was performed with 5 sets of repetitions at 65% 1-repetition maximum until volitional fatigue. Blood samples were collected at baseline, immediately postexercise, and 60 min postexercise to assess glucose and insulin. Cortisol was assessed immediately and at 60 min postexercise. No significant performance benefits were observed for any RE. CHO+BCAA (152.4 ± 71.4 ng/mL) resulted in the lowest cortisol levels, which was lower than BCAA and PLA (193.7 ± 88.5, 182.8 ± 67.5 ng/mL, p < 0.05), but not different from CHO (165 ± 76.5 ng/mL, p = 0.342). Postexercise insulin concentrations were significantly higher with CHO (4.79 ± 3.4 mU/L) compared with BCAA and PLA (3.7 ± 2.0, 3.5 ± 1.8 mU/L, p < 0.05), but not different from CHO+BCAA (4.3 ± 2.5 mU/L, p = 0.339). There was no treatment effect for glucose, but glucose significantly increased from baseline to immediately postexercise and significantly decreased at 60 min postexercise. Ingesting beverages containing CHO with or without BCAA during upper body resistance exercise may promote a more favorable postexercise less catabolic environment.