According to our knowledge, there are no previous studies where the PRAL method is used to evaluate the quality of food for the investigation of the effect of nutrition on aerobic performance in humans. Thus, the purpose of this study was to explore if a low-protein vegetarian diet, which was designed with the help of PRAL to enhance the production of bases, has an effect on acid–base balance in men. Moreover, the study was planned to determine whether the possible changes C646 chemical structure in venous blood acid–base status influence performance or fuel selection during submaximal and maximal cycling. It was hypothesized that a diet low in protein and rich in alkali-producing vegetables
and fruits may have the potential to alter the blood acid–base status and, thus, enable higher aerobic capacity and influence fuel selection during exercise. Methods Subjects Nine healthy, recreationally active men volunteered for the study and signed an informed consent.
Subjects were students of University of Jyväskylä and were exercising recreationally (e.g. learn more walking, jogging, cycling, resistance training). Subjects who were obese (body mass index above 30), were training for competitive purposes, were using any medication or had any food allergy were excluded from the study. Ethical approval for the study was obtained from the University’s Ethics Committee and the study followed the declaration of Helsinki. Pre-testing Before the actual experimental cross-over design, VO2max and maximal workload of the subjects were measured (measurement 1, M1). Before M1 the subjects followed their normal diet and kept food diaries for 4 days, thus, the eating and drinking habits of the subjects were checked to be in accordance with general dietary guidelines. On the fifth
day, the subjects performed M1, which was an incremental VO2max test performed on a mechanically braked cycle ergometer (Ergomedic 839E, Monark Exercise AB, Thymidine kinase Vansbro, Sweden). The workload was initially 75 W and was increased by 25 W every 2 min until exhaustion. The pedaling GSK458 manufacturer frequency was sustained at 60 rpm throughout the test. Before the ergometer test, height, weight and body mass index (BMI) of the subjects were determined. For the estimation of body fat percentage, a 4-point skinfold method was used. Thicknesses of biceps, triceps, subscapular and suprailiac skinfolds were measured and standard equations of Durnin & Womersley  were used for the determination of fat percentage. Experimental design The study design is presented in Figure 1. After M1, subjects were randomly divided into two groups. Group 1 (n=5) followed a normal diet (ND) first and then a low-protein vegetarian diet (LPVD). Group 2 (n=4) followed LPVD first and then ND.