Short-Time β-Alanine Supplementation on the Acute Strength Performance after High-Intensity Intermittent Exercise in Recreationally Trained Men

Abstract

(1) Background: We investigated the effects of 28 days of beta-alanine (β-alanine) supplementation on the acute interference effect of high-intensity intermittent exercise (HIIE) on lower-body resistance exercise performance, body composition, and strength when combined with a resistance training program. (2) Methods: Twenty-two males were randomized into: β-alanine supplementation (6.4 g/day) or placebo (6.4 g/day maltodextrin) during 28 days. Total body water, intracellular and extracellular water, fat-free mass (FFM), and fat mass were assessed using bioelectrical impedance. Participants performed 5000-m HIIE (1:1 effort and rest ratio) followed by resistance exercise (four sets of 80% at 45° leg press until muscular failure) at baseline and after 28 days. The resistance training program consisted of three sets of 10 to 12 RM with 90 s of rest, four days per week. (3) Results: For the post-HIIE leg press volume, higher values were observed post-training than pre-training, but no group x time interaction was observed. There was a non-significant trend for an interaction in the FFM change (β-alanine = 2.8% versus placebo = 1.0%, p = 0.072). (4) Conclusion: Twenty-eight days of β-alanine supplementation did not prevent acute strength loss during resistance exercise after high-intensity interval exercise, nor increase strength or hypertrophic adaptations associated with resistance training.

Effects of beta-alanine supplementation on body composition: a GRADE-assessed systematic review and meta-analysis

“…The observed beneficial effects of beta-alanine supplementation on lean mass in prior research can be attributable to beta-alanine’s ability to promote fluid shifts into muscle and subsequent increases in intramuscular water, which have been claimed to account for part of the gains in FFM [ 12 , 50 ]. However, Freitas et al showed that 28 days of beta-alanine supplementation did not increase total or intracellular water content during resistance training after HIIT [ 32 ]. In addition, recent studies were unable to measure intramuscular carnosine concentrations or myofibrillar protein content in the exercised muscles to prove their claims toward beneficial effects of beta-alanine supplementation on lean mass through muscle hypertrophy [ 32 , 40 , 41 ].…”

“…However, Freitas et al showed that 28 days of beta-alanine supplementation did not increase total or intracellular water content during resistance training after HIIT [ 32 ]. In addition, recent studies were unable to measure intramuscular carnosine concentrations or myofibrillar protein content in the exercised muscles to prove their claims toward beneficial effects of beta-alanine supplementation on lean mass through muscle hypertrophy [ 32 , 40 , 41 ]. As can be seen from the subgroup analysis, differences between studies in terms of study duration, dosages of beta-alanine, and exercise type did not change the overall impacts of beta-alanine supplementation on body mass or lean mass.…”

“…Second, it is important to note that most previous studies employed well-trained men with a lower baseline BFP; thus, the further fat loss was unexpected. Finally, the positive effects of beta-alanine supplementation on improvements in exercise performance are thought to be due to increases in intramuscular concentrations of carnosine, although the majority of RCTs included in our investigation did not measure carnosine concentrations [ 11 , 31 , 32 , 35–38 , 40 , 41 , 54 ]. Therefore, the results of these studies should be interpreted with caution.…”

Concurrent Training and the Acute Interference Effect on Strength: Reviewing the Relevant Variables

“…The main changeable variables of AT protocols are exercise intensity (15,52), mode (16,39), and volume (43); duration of recovery interval between exercises (7,8,37); and active muscles involved (15,47). In addition, ergogenic aids are also a factor that have been considered in possibly offsetting the deleterious interference effect on strength performance during a CT session (2,3,19,20,47). If the training program's priority is muscle strength development, all these factors should be considered to optimize CT organization and prescription.…”

“…To eliminate or at least minimize the acute interference effects, the utilization of ergogenic aids has been considered by some investigations (2,3,19,20,30,45).…”