Effects of short-term betaine supplementation on muscle endurance and indices of endocrine function following acute high-intensity resistance exercise in young athletes

Figures & data

Figure 1. Mean of dietary intake 48 h before either testing session.

Figure 2. Research time line. 1RM, 1 repetition maximum.

Figure 3. The number of repetitions (reps) per set of the leg press (a), and bench press (b) workout in adolescent male handballers (n = 10) after 14 days betaine supplementation vs. placebo intake. ^a p < 0.05, ^aa p < 0.01, and ^aaa p < 0.001 vs. set 1; ^b p < 0.05, and ^bbb p < 0.001 vs. set 2; ^c p < 0.05 vs. set 3.

Figure 4. Changes in plasma testosterone (a), cortisol (b), testosterone to cortisol ratio (c), and lactate (d) in response to a session of high-intensity resistance exercise in adolescent male handballers (n = 10) after 14 days betaine supplementation vs. placebo intake. ^a p < 0.05, ^aa p < 0.01, and ^aaa p < 0.001 vs. baseline; ^bbb p < 0.001 vs. before exercise; ^† p < 0.05, ^†† p < 0.01, and ^††† p < 0.001 vs. placebo.

Figure 5. Effect size estimates (generalized eta squared) after 14 days betaine supplementation vs. placebo intake for each blood parameter measured in this study.

Data availability statement

The datasets used and/or analyzed during the present study are available from the corresponding author on reasonable request.