Alkaline Diet Improves Vertical Jump Performance in Volleyball Players
H Eryiğit International Journal of Sport Nutrition and Exercise Metabolism 2020
Increased buffering capacity helps to maintain muscle contraction and delay muscle fatigue during high intensity exercise. In this regard various nutritional supplements increasing buffering capacity are used to improve high intensity exercise performance. In recent years, it has been postulated that an alkaline diet may also increase the exercise performance by creating a buffering effect. Therefore, the aim of the current research is to compare the acute effects of alkaline (ALD) and acidic diets (ACD) on anaerobic performance and hydration level in volleyball players. Eleven semi-professional male volleyball players (age = 20 ± 1 y, training age = 9 ± 3 y) voluntarily participated in the study in a randomized, single-blind, cross-over design. Each participant visited the laboratory three times: baseline (B) measurements were taken with their unmodified usual diet, followed by two measurements following a 4-day ACD or ALD program with a 1-week washout period between. ACD and ALD contents were calculated individually and the participants were provided with packed daily meals. Measured variables included urine pH, 30 sec Wingate anaerobic exercise performance, countermovement jump (CMJ) and squat jump (SJ) performances, and blood lactate (La). Repeated measures ANOVA was used to analyse the data. Bonferroni correction was used as post-hoc analysis. No main effect of diet was found on Wingate anaerobic exercise performance (p > .05). However, both SJ and CMJ performance increased significantly with the alkaline diet (CMJ (cm); ALD 40.7 ± 6.4, ACD 39.9 ± 5.9, baseline 38.9 ± 6.5, p < .05; SJ (cm); ALD 37.6 ± 5.7, ACD 36.3 ± 5.3, baseline 35.4 ± 6.0, p < .05). Hydration level (ALD 1017 ± 4, ACD 1024 ± 4, baseline 1019 ± 4.9, p < .05) and urine pH (ALD 6.7 ± 0.5, ACD 5.1 ± 0.3, baseline 5.2 ± 0.4, p < .05) were significantly different in favour of the ALD while no difference was found between BLa levels (mmol/L, ALD 6.2 ± 2.0 ACD 6.2 ± 1.3, baseline 6.8 ± 1.8, p > .05). As a result; volleyball players may be advised to have an alkaline diet starting four days before the matches.
An alkaline diet can be an easy and natural way to improve hydration and increase vertical jump performance for athletes. However, more studies are needed to elucidate the effect of alkaline diet on anaerobic performance.