Ingestion of a drink containing carbohydrate increases the number of bench press repetitions

Abstract

Objective The aim of this study was to analyze the effects of carbohydrate ingestion prior to exercise on the number of bench press repetitions. Methods Eight male physically active (21.3±2.7 years, 176±5cm, 73.12±6.12kg), with a minimum experience of at least one year exercising regularly, visited the laboratory at three moments. During the first visit, candidates went through their anthropometric evaluation and the application of their maximum number of bench press repetitions. The experimental tests were performed during their second and third visits in a crossover and blind study. The participants performed the maximum number of repetitions with an intensity of 70% of their maximum repetition strength. One hour before the experimental trials, participants randomly ingested a solution containing either carbohydrate or a placebo. Results The ingestion of carbohydrate increases muscle resistance in relation to placebo (p=0.014; effect size=0.71). This is evidenced by the increase in the number of repetitions (12.9±2.4 and 11.3±1.9, respectively). The individual’s perception of effort is higher in the carbohydrate group than in the placebo group after exhaustion (4±0.93 and 3.1±0.64, respectively, p=0.006, effect size=0.89). Conclusion It is concluded that a previous intake of carbohydrate is useful in improving performance in resistance exercises, providing an increase in the individual’s perception of effort.

The Effect of Carbohydrate Intake on Strength and Resistance Training Performance: A Systematic Review

“…Nineteen publications met the inclusion criteria [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44], summarized in Table 3 and Figure 2. Sixteen studies were crossover trials with an average of 11 ± 4 participants (median: 9) [26][27][28][29][30][31][34][35][36][37][38][39][41][42][43][44]; three studies were randomized controlled trials (RCTs) with an average of 11 ± 5 participants (median: 9) per group [32,33,40]. Participants were young, with an average age of 23 ± 2 years.…”

“…Participants were young, with an average age of 23 ± 2 years. Training status of the participants was categorized as untrained [32], physically active [42], CrossFit trained [38,44], recreationally trained [27,40,43] or strength-trained [26,[28][29][30][31][33][34][35][36][37]39,41]. All participants were men except for 6 of the 17 participants in Fairchild et al [27] and all 13 in Raposo [37].…”

“…The participants were in fasted or unspecified conditions in 13 studies before carbohydrate manipulation and the performance tests [27,[29][30][31][32][33][36][37][38][39]41,42,44]; six studies were performed with both groups in a fed state (2.5-5 h) before performance was measured [26,28,34,35,40,43]. Only one of the studies was isocaloric [36].…”

“…Workout types included traditional strength training [26,[29][30][31][32][33][34][35]37,[39][40][41][42][43], CrossFit [38,44], circuit training [36], and isokinetic exercise [27,28]. Fifteen studies measured performance as repetitions to failure, sets to predetermined repetition failure, total training volume and/or total work (kJ) during traditional strength exercises [26,[29][30][31][32][33][34][35][37][38][39][40][41][42][43] or CrossFit [36,44], of which one also included peak power [30] and two studies measured isokinetic performance (average and peak power, isokinetic peak or average torque, total and average work across sets) [27,28]. Four studies also measured secondary outcomes, such as agility and sprint time [29,36], jump distance and throwing performance [29] and work output measured as caloric expenditure during maximal effort rowing [38].…”

“…Of the eight studies with a significant between-group effect, six favored the higher-carbohydrate condition: five studies reported more repetitions to failure/training volume [29,30,39,40,42] (but not peak power [30]) and one study reported greater isokinetic performance [28]. In these studies, the higher-carbohydrate conditions also had a higher energy intake, because the control conditions were either continuing their overnight fast [39], received a non-caloric placebo after an overnight fast [30] or in an unspecified state [42], received 5.5 g amino acids as placebo [29] or received a non-caloric placebo 3-5 h after a meal [28,40]. None of the isocaloric comparisons found the higher carbohydrate condition had greater performance than the lower carbohydrate condition [36,40,44].…”