Acute Citrulline-Malate Supplementation Increases Total Work in Short Lower-Body Isokinetic Tasks for Recreationally Active Females During Menstruation

Abstract

Gills, JL, Spliker, B, Glenn, JM, Szymanski, D, Romer, B, Lu, H-C, and Gray, M. Acute citrulline-malate supplementation increases total work in short lower-body isokinetic tasks for recreationally active females during menstruation. J Strength Cond Res 37(6): 1225-1230, 2023-Citrulline-malate (CM) exhibits acute ergogenic benefits through nitric oxide production (NO) and augmentation of vasodilatory properties. Nitric oxide is upregulated by estrogen and may influence CM's ergogenic efficacy in women. Therefore, the objective of this study was to evaluate the acute effects of CM supplementation on lower-body isokinetic performance in recreationally active women. Nineteen women (23.5 6 3.1 years; 164.8 6 7.0 cm; 61.9 6 27.4 kg; 28.8 6 8.1% body fat) completed 2 randomized, double-blind, crossover trials consuming CM (8 g CM + 12 g dextrose) or placebo (12 g dextrose). For testing trials, subjects were in the menstruating portion of the follicular phase of their menstrual cycle. Subjects performed a 5repetition isokinetic leg extension protocol (5RP) followed by a 50-repetition isokinetic leg extension protocol (50RP), 60 minutes after supplement consumption. Repeated measures analysis of variance analysis showed that CM significantly increased total work completed, relative total work, and total work during maximum repetition compared with placebo (p , 0.05); but no significant performance differences existed between trials for peak torque production (p 5 0.14) for the 5RP. No significant differences were identified between trials for peak torque production (p 5 0.69) or total work (p 5 0.33) completed during the 50RP. CM increased total work completed during the 5RP, but provided no ergogenic benefit during the 50RP in recreationally active menstruating women. CM amplifies power-based resistance exercise performance in women during the follicular phase of the menstrual cycle, potentially because of depressed estrogen levels. Additional research is needed to identify timing efficacy of CM to increase sport performance during each phase of the menstrual cycle.

Supplementation with Nitric Oxide Precursors for Strength Performance: A Review of the Current Literature

“…An acute 8 g dose of CitMal has been shown to enhance maximal hand grip strength as well as peak power output during a 30 s Wingate test in a sample of female Masters tennis athletes [ 61 ]. Gills et al [ 62 ] demonstrated that an acute 8 g dose of CitMal significantly increased work performed during a bout of five maximal isokinetic leg extensions, but provided no ergogenic benefit during 50 repetitions of maximal isokinetic leg extensions in recreationally trained women. Most other studies showing favorable effects have evaluated the effect of CitMal supplementation on muscle endurance during high-intensity resistance training as indicated by repetitions to failure.…”

Acute Effect of L-Citrulline Supplementation on Resistance Exercise Performance and Muscle Oxygenation in Recreationally Resistance Trained Men and Women

“…Citrulline malate is typically provided as an acute 8 g (g) dose in a 1:1 or 2:1 ratio which would yield approximately 4.0 to 5.3 g of L-citrulline and 3.7 to 4.0 g of malate. Some studies have shown that 8 g of citrulline malate could delay fatigue, improve power output, and increase the work performed during resistance exercise [ 8 , 9 , 10 , 11 , 12 , 13 ]. However, others have failed to demonstrate an ergogenic benefit following 8 g of citrulline malate [ 14 , 15 , 16 , 17 , 18 , 19 ].…”