The evidence of the effect of L-citrulline/malate on sport performance is mixed and varies between a negative effect to a positive effect. The negative effects were found in one study analysed for this review, here only L-citrulline was supplemented. In Energy Water, L-citrulline is ingested combined with malate, which is a different ingredient and, as described, displays different properties. The three studies that found positive effects on the sport performance, combined L-citrulline ingestion with other ingredients, like sucrose and BCAAs, therefore the positive effect cannot be directly linked to L-citrulline, even though there was an increase in NO concentration. It could be hypothesized that a prolonged intake of L-citrulline, combined with L-arginine, can improve sport performance. This is not scientifically substantiated and also does not fit the requirements for Energy Water, since Energy Water is not a daily supplement. One out of two studies that found a direct positive effect of L-citrulline intake was I Suzuki et al. (2016). It should be taken into account that this study had a prolonged intake of L-citrulline, which does not fit the requirements of EW. Which is in line with the findings of Cutrufello et al (2015) that a single dose is uneffective. The other study that found a positive effect on severe intensity performance (Bailey et al., 2015). Here should be noted that this research was performed with only 10 males, which is a rather small group for drawing solid conclusions. Also, it is important to note that some studies only measured indirect factors and not, for example, time to exhaustion. In studies performed on L-citrulline or L-citrulline/malate, mainly the effect on males was investigated. It is possible that there is a difference between males and females, since they have a different hormone balance. Females have a higher level of oestrogens, which give an upregulation of NO production (Glenn et al., 2017). No effect was observed between males and females (Cutrufello et al., 2015).
The effect of malate itself on performance is not clear. When combined with L-citrulline, it is suggested by one of the analysed studies that L-citrulline/malate supplementation does improve sport performance. Therefore we use L-citrulline and malate in combination with BCAA in Energy Water.