Effects of a commercially available branched-chain amino acid-alanine-carbohydrate-based sports supplement on perceived exertion and performance in high intensity endurance cycling tests

Abstract

Background: Sports nutritional supplements containing branched-chain amino acids (BCAA) have been widely reported to improve psychological and biological aspects connected to central fatigue and performance in endurance exercise, although the topic is still open to debate. The aim of the present study was to determine whether the intake of a commercially available BCAA-based supplement, taken according to the manufacturer's recommendations, could affect the rating of perceived exertion (RPE) and performance indexes at the beginning (1d) and end of a 9-week (9w) scheduled high intensity interval training program, with an experimental approach integrating the determination of psychometric, performance, metabolic and blood biochemical parameters. Methods: This was a randomized double-blind placebo-controlled study. Thirty-two untrained, healthy young adults (20 males and 12 female) were enrolled. A high-intensity endurance cycling (HIEC) test was used to induce fatigue in the participants: HIEC consisted in ten 90 s sprints interspersed by ten 3 min recovery phases and followed by a final step time to exhaustion was used. In parallel with RPE, haematological values (creatine kinase, alanine, BCAA, tryptophan, ammonia and glucose levels), and performance indexes (maximal oxygen consumption-VO 2max , power associated with lactate thresholds-W LT1 , W LT2 and time to exhaustion-TTE) were assessed. All subject took the supplement (13.2 g of carbohydrates; 3.2 g of BCAA and 1.6 g of L-alanine per dose) or placebo before each test and training session. Dietary habits and training load were monitored during the entire training period. Results: The administration of the supplement (SU) at 1d reduced RPE by 9% during the recovery phase, as compared to the placebo (PL); at 9w the RPE scores were reduced by 13 and 21% during the sprint and recovery phase, respectively; at 9w, prolonged supplement intake also improved TTE and TRIMP. SU intake invariably promoted a rapid increase (within 1 h) of BCAA serum blood levels and prevented the post-HIEC tryptophan: BCAA ratio increase found in the PL group, at both 1d and 9w. There was no difference in dietary habits between groups and those habits did not change over time; no difference in glycemia was found between SU and PL. VO 2max , W LT1 and W LT2 values improved over time, but were unaffected by supplement intake.

High-intensity Interval Training Promotes the Shift to a Health-Supporting Dietary Pattern in Young Adults

“…Before the beginning of the training period, an incremental ramp test was performed by every subject, in order to set the individual training zones, based on the heart rate (HR) recorded at the first and second lactate thresholds (LTs); maximal oxygen consumption (VO 2 max) was also assessed. For further information about training zones definition, see Gervasi et al [17]. Each session was designed following the same training intensity distribution, based on a polarized model, with around 70% of session time spent in zone 1, 10% spent in zone 2 and 20% spent in zone 3, according to Seiler and Kjerland [18].…”

“…The frequency and duration of the sessions are also indicated. Modified with permission from Gervasi et al[17].…”

Ergogenic Effect of BCAAs and L-Alanine Supplementation: Proof-of-Concept Study in a Murine Model of Physiological Exercise

“…Therefore, the combination of ALA with BCAAs should help to preserve the pool of exogenously administered BCAAs, in parallel optimizing the effects on protein turnover. Dietary supplements combining different mixtures of BCAAs and ALA are commercially available and already in use by fitness enthusiasts and professionals [30]. However, to date, no solid preclinical data have been provided about their effects, or about the optimal BCAAs/ALA ratio required to maximize both direct and indirect effects of ALA, in parallel increasing BCAAs bioavailability.…”

“…However, to date, no solid preclinical data have been provided about their effects, or about the optimal BCAAs/ALA ratio required to maximize both direct and indirect effects of ALA, in parallel increasing BCAAs bioavailability. In a recent paper, the evaluation of the effects of a commercially available sports supplement containing BCAAs plus ALA was conducted in high-intensity endurance cycling tests [30]. The main finding was the reduction of perceived exertion rating and recovery times during performance [30].…”

“…In a recent paper, the evaluation of the effects of a commercially available sports supplement containing BCAAs plus ALA was conducted in high-intensity endurance cycling tests [30]. The main finding was the reduction of perceived exertion rating and recovery times during performance [30].…”