The effect of two β-alanine dosing strategies on 30-minute rowing performance: a randomized, controlled trial

Abstract

Backgroundβ-alanine (βA) supplementation has been shown to increase intramuscular carnosine content and subsequent high-intensity performance in events lasting < 4 minutes (min), which may be dependent on total, as opposed to daily, dose. The ergogenic effect of βA has also been demonstrated for 2000-m rowing performance prompting interest in whether βA may be beneficial for sustained aerobic exercise. This study therefore investigated the effect of two βA dosing strategies on 30-min rowing and subsequent sprint performance.MethodsFollowing University Ethics approval, twenty-seven healthy, male rowers (age: 24 ± 2 years; body-height: 1.81 ± 0.02 m; body-mass: 82.3 ± 2.5 kg; body-fat: 14.2 ± 1.0%) were randomised in a double-blind manner to 4 weeks of: i) βA (2.4 g·d− 1, βA1); ii) matched total βA (4.8 g on alternate days, βA2); or iii) cornflour placebo (2.4 g·d− 1, PL). Participants completed a laboratory 30-min rowing time-trial, followed by 3x30-seconds (s) maximal sprint efforts at days 0, 14 and 28 (T1-T3). Total distance (m), average power (W), relative average power (W·kg− 1), cardio-respiratory measures and perceived exertion were assessed for each 10-min split. Blood lactate ([La-]b mmol·L− 1) was monitored pre-post time-trial and following maximal sprint efforts. A 3-way repeated measures ANOVA was employed for main analyses, with Bonferonni post-hoc assessment (P ≤ 0.05).ResultsTotal 30-min time-trial distance significantly increased from T1-T3 within βA1 only (7397 ± 195 m to 7580 ± 171 m, P = 0.002, ƞp2 = 0.196), including absolute average power (194.8 ± 18.3 W to 204.2 ± 15.5 W, P = 0.04, ƞp2 = 0.115) and relative average power output (2.28 ± 0.15 W·kg− 1 to 2.41 ± 0.12 W·kg− 1, P = 0.031, ƞp2 = 0.122). These findings were potentially explained by within-group significance for the same variables for the first 10 min split (P ≤ 0.01), and for distance covered (P = 0.01) in the second 10-min split. However, no condition x time interactions were observed. No significant effects were found for sprint variables (P > 0.05) with comparable values at T3 for mean distance (βA1: 163.9 ± 3.8 m; βA2: 161.2 ± 3.5 m; PL: 162.7 ± 3.6 m), average power (βA1: 352.7 ± 14.5 W; βA2: 342.2 ± 13.5 W; PL: 348.2 ± 13.9 W) and lactate (βA1: 10.0 ± 0.9 mmol·L− 1; βA2: 9.2 ± 1.1 mmol·L− 1; PL: 8.7 ± 0.9 mmol·L− 1).ConclusionsWhilst daily βA may confer individual benefits, these results demonstrate limited impact of βA (irrespective of dosing strategy) on 30-min rowing or subsequent sprint performance. Further investigation of βA dosage > 2.4 g·d− 1 and/or chronic intervention periods (> 4–8 weeks) may be warranted based on within-group observations.

Effects of Beta-Alanine Supplementation on Physical Performance in Aerobic–Anaerobic Transition Zones: A Systematic Review and Meta-Analysis

“…The meta-analysis showed high heterogeneity among the studies reviewed (I 2 = 94%; p = 0.00001). All studies analyzed declared a beneficial effect of supplementation with BA on physical performance in LDT [17,28].…”

“…The search strategy and study selection are shown in Figure 4. Out of 19 studies, eight considered time in a TTT to assess the effect of BA supplementation on physical performance [29,[42][43][44][45][46][47][48], nine used time (LTT) on a TTE test to assess the same effect [5,21,22,35,[49][50][51][52][53], one considered the distance (LDT) on a TTE test [28], while one considered both the time (LTT) and the distance (LDT) on a TTE test [17] ( Table 1).…”

“…Two studies were considered for this analysis [17,28]. However, the study of Baesley et al [28] included two experimental groups for the LDT in their research design (30 min on a rowing ergometer with 2.4 g/day of BA supplementation every 24 h and 30 min on a rowing ergometer with 4.8 g/day of BA supplementation every 48 h). In this way, three studies were included in the meta-analysis that calculated the effect of BA supplementation on the TTE test.…”

“…The meta-analysis of [La] (mmol•L −1 ) included 11 studies [5,17,21,28,29,35,43,[46][47][48][49]. The total number of cases supplemented with BA included 128 participants, while 121 participants were supplemented with PL.…”

“…The meta-analysis showed that BA supplementation generated a trivial and non-significant effect on [La] post effort (SMD, 0.16; 95% CI −0.35-0.67; p = 0.53), while moderate heterogeneity was present among the reviewed studies (I 2 = 71%; p = 0.0001). A meta-analysis of absolute VO 2 max (LO 2 •min −1 ) included nine studies [5,22,28,43,45,[50][51][52][53]. The total number of cases supplemented with BA included 109 participants, while the PL group comprised 104 participants.…”