The Effect of High-Intensity Interval Training Combined with Beta-Alanine Supplementation on Cardiorespiratory Performance and Blood Lactate in Active Women

Background & objectives: Beta-alanine supplementation is known to enhance athletic performance.The aim of this study was to evaluate the effect of a period of high-intensity interval training (HIIT) combined with beta-alanine supplementation on cardiorespiratory performance and blood lactate levels in active women.Methods: Thirty-two active young women were divided into four groups (eight individuals per group): control (placebo), supplement, and training combined either with placebo or supplement.In the pre-test and post-test, blood samples were collected, and cardiorespiratory performance was evaluated by measuring maximum heart rate (HRmax), distance walked, aerobic power (VO2max), and blood lactate levels were evaluated after Cooper's test.The supplement group received four grams of beta-alanine daily for eight weeks, while the training groups completed an eight weeks HIIT program.Data were analyzed using two-way repeated measures analysis.Results: There was no significant difference in distance walked and VO2max between the four groups at both time points.However, significant differences were observed in HRmax and blood lactate levels among the groups (p<0.05).HRmax and blood lactate of the supplement and training group were significantly lower than the other three groups, and blood lactate of the supplement group was also significantly lower than the control group (p<0.05).Additionally, the supplement and training group had significantly increased distance walked and VO2max compared to the control and training with placebo group, and the supplement group compared to the control group (p<0.05). Conclusion:The combination of HIIT and beta-alanine supplementation had a more pronounced effect on cardiorespiratory performance and blood lactate levels in active women compared to either intervention alone.