Citrulline Malate Fails to Improve German Volume Training Performance in Healthy Young Men and Women

Abstract

Background: Citrulline malate (CM) is purported to buffer lactic acid, enhance oxygen delivery, and attenuate muscle soreness. Anaerobic exercise trials with CM have produced conflicting results. Objective: The aim of the current investigation was to test the efficacy of CM on resistance training (RT) with the hypothesis that CM would improve performance. Design: A double-blind, counterbalanced , randomised control trial was utilised to assess the effects of CM on RT. 19 subjects (8 female) (25.7 ± 7.7 years), regularly engaged in RT consumed either 8 g of CM (1.1 : 1 ratio) or a placebo (6 g citric acid). Subjects attempted to perform a German Volume Training (GVT) protocol comprising 10 sets of 10 repetitions of barbell curls at 80 % of their one repetition maximum. Results: Repeated ANOVA suggested no effect of CM on RT performance (treatment × time × order p = 0.217). There was no difference (p = 0.320) in the total number of reps over the ten sets (CM median = 57, IQR 45 to 73; placebo median = 61, IQR 51 to 69). Blood lactate and creatine kinase did not differ between CM and placebo (p > 0.05). Finally, total muscle soreness was reduced significantly in CM compared to placebo (treatment × time × order p = 0.004). Conclusions: These results require corroboration; an ergogenic benefit is yet to be established and weight trainers should exercise caution when assessing the efficacy of CM. Future research should focus on the potential effects of loading doses of CM.

Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis

“…Therefore, we used the sum of all repetitions performed for all 3 days combined in the analysis. Moreover, in Chappell et al (2018b), the SDs of only Set 1 and Set 10 were reported in the text, whereas all sets were presented in a figure.…”

“…The literature search resulted in 84 potential studies after removal of duplicates (Figure 1). Following screening, a total of eight studies met the inclusion criteria (Chappell et al, 2018a(Chappell et al, , 2018bda Silva et al, 2017;Glenn et al, 2015;Gonzalez et al, 2017;Pérez-Guisado & Jakeman, 2010;Wax et al, 2015aWax et al, , 2015b. There were a total of 137 participants (26 females) with an age of 25.4 ± 5.4 (mean ± SD) years old.…”

“…Nevertheless, several studies have investigated the ergogenic potential of CitMal supplementation on both aerobic and anaerobic exercise performance (Gonzalez & Trexler, 2020). Due to its potential to delay fatigue during highintensity exercise, studies have specifically investigated the acute effects of CitMal supplementation on strength, power, and resistance training performance (Chappell et al, 2018a(Chappell et al, , 2018bCunniffe et al, 2016;Cutrufello et al, 2015;da Silva et al, 2017;Farney et al, 2017;Glenn et al, 2015Glenn et al, , 2016Gonzalez et al, 2017;Martínez-Sánchez et al, 2017;Pérez-Guisado & Jakeman, 2010;Trexler et al, 2019a;Wax et al, 2015aWax et al, , 2015b. Although these studies have offered mixed findings, some have shown that acute CitMal supplementation may increase performance during highintensity strength and power tasks.…”

“…Here, several of the studies have demonstrated that subjects who consume a single dose of CitMal (6-8 g) experience less fatigue to the working muscles compared with a placebo groupallowing them to perform more repetitions to failure (Pérez-Guisado & Jakeman, 2010;Wax et al, 2015aWax et al, , 2015b). However, not all studies have shown such favorable results (Chappell et al, 2018a(Chappell et al, , 2018bda Silva et al, 2017;Gonzalez et al, 2017). Recently, a published meta-analysis has indicated a small beneficial effect of CitMal supplementation on high-intensity strength and power performance; however, the analysis included several different strength and power variables from resistance training and sprinting performance tests involving large muscle groups (Trexler et al, 2019b).…”

Supplementary Nitric Oxide Donors and Exercise as Potential Means to Improve Vascular Health in People with Type 1 Diabetes: Yes to NO?

“…Moreover, as a commercially available sports supplement, CM has been linked to positive exercise performance outcomes, which are mainly driven by its anti-asthenic effect on muscle fatigue [107,125,126,127,128]. However, there is considerable disagreement on this topic within the literature, since several studies have failed to observe any ergogenic potential of CM regardless of variations in dosing strategies [129,130,131,132].…”