Purpose: The present study investigated the effects of β-alanine supplementation only, and in combination with sprint-interval training (SIT), on training intensity, and energy provision and performance during exhaustive supramaximal-intensity cycling and a 4- and 10-km time trial (TT).
Methods: Fourteen trained cyclists (V˙O2max = 4.5 ± 0.6 L·min−1) participated in this placebo-controlled, double-blind study. Subjects performed a supramaximal cycling test to exhaustion (equivalent to 120% V˙O2max) and a 4- and 10-km TT and 4 × 1-km sprints at three time points: before and after 28 d of supplementation loading (6.4 g·d−1) with β-alanine (n = 7) or a placebo (n = 7), and after a 5-wk supervised, SIT program performed twice weekly (repeated 1-km cycling sprints) while maintaining supplementation with β-alanine (1.2 g·d−1) or a placebo.
Results: After the loading period, sprints 3 and 4 of the 4 × 1-km sprint intervals were improved with β-alanine supplementation (4.5% ± 3.4% and 7.0% ± 4.0%; P < 0.05, respectively). After 5 wk of SIT, training intensity increased in both groups but the change was greater with β-alanine supplementation (9.9% ± 5.0% vs 4.9% ± 5.0%; P = 0.04). β-alanine supplementation also improved supramaximal cycling time to exhaustion to a greater extent than placebo (14.9% ± 9.2% vs 9.0% ± 6.9%; P = 0.04), whereas 4- and 10-km TT performance improved to a similar magnitude in both groups. After SIT, β-alanine also increased anaerobic capacity (5.5% ± 4.2%; P = 0.04), whereas V˙O2peak increased similarly in each group (3.1% ± 2.9% vs 3.5% ± 2.9%; P < 0.05).
Conclusions: These findings indicate that β-alanine supplementation enhances training intensity during SIT and provides additional benefits to exhaustive supramaximal cycling compared with SIT alone.
1Griffith University Sport Science, School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, AUSTRALIA; and 2Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, AUSTRALIA
Address for correspondence: Phillip Bellinger, BExSci Hons Ph.D. Scholar, Griffith University Sport Science School of Allied Health Sciences Griffith University, 4222 Queensland, Australia; E-mail: email@example.com.
Submitted for publication May 2016.
Accepted for publication July 2016.