Daily Nitrate Supplementation for The Greatest Performance Gains!

Dwayne N. Jackson, PhD

Whether your athletic interests are endurance-based, strength-based, or aesthetically based, one fact is certain— energy is something we all could use a little more of. Based on this (and some of the most recent scientific evidence), you may want to give citrulline malate a try.

Citrulline malate is formed by the chemical bonding of citrulline to malate. Supplement R&D teams have been interested in this compound for years due to its potential to increase muscle blood flow and ATP (energy) levels–thus, delaying fatigue, promoting increased workout intensity, and supporting faster recovery.

Citrulline was originally isolated from watermelon. However, it is produced in the body by the conversion of other amino acids and is considered to be non-essential. One means for citrulline production in the body is through the conversion of L-arginine to nitric oxide (NO, a potent vasodilator), whereby NO synthase (an enzyme) oxidizes L-arginine to form NO and citrulline. Interestingly though, when citrulline is taken as a supplement, the kidneys can covert some of it back to arginine, which boosts blood arginine levels better than taking arginine itself—which promotes even greater NO production and blood flow to working muscle. The end result???—– Increased oxygen and nutrient delivery, removal of metabolic byproducts, and incredible pumps. In terms of clearing metabolic byproducts, citrulline is also key player in the urea cycle, a biological pathway whereby we remove of toxic ammonia that can build up from heightened protein metabolism due to intense training.

The malate component of citrulline malate is found in many sour fruits (e.g., green apples and sour grapes) and it gives them their tartness. From a metabolic perspective, malate is an important intermediate in Kreb’s cycle that produces ATP (energy) during aerobic performances.

Numerous studies have shown that taking citrulline supplements (like L-citrulline or citrulline malate) promotes great performance benefits in athletes of all levels. In a recent study, published in the European Journal of Nutrition, researchers evaluated the performance benefits of an 8 g preworkout dose of citrulline malate on upper- and lower-body submaximal resistance exercise performance to exhaustion during bench press (at 80% 1RM) and leg press (at 80% 1RM) in trained female weightlifters. The authors concluded that taking 8 g of citrulline malate, 1-hour prior to exercise, increased the number of repetitions completed during bench press (3% increase) and during leg press (17% increase). Notably, when athletes took citrulline malate, their ratings of perceived exertion were significantly lower from set-to-set, especially during bench press exercise.

ACTION POINT: We generally suggest taking at least 6 g of L-citrulline or citrulline malate 30-60 min prior to exercise or sports performance. However, based on the findings in this study, female athletes may benefit by taking as much as 8 g of L-citrulline or citrulline malate prior to training. Females may benefit from a little more citrulline because their hormones promote greater NO production than their male counterparts. As always, start with a lower dose and build slowly to higher doses to assess tolerance.

Reference:

Glenn JM, Gray M, Wethington LN, Stone MS, Stewart RW Jr, Moyen NE. Acute citrulline malate supplementation improves upper- and lower-body submaximal weightlifting exercise performance in resistance-trained females. Eur J Nutr. 2017 Mar;56(2):775-784.

Beetroot extract and other nitrate-rich supplements are gaining popularity in strength and endurance athletes, as dietary nitrates are known to increase nitric oxide levels in the body. Nitric oxide is used by the vascular endothelium to trigger relaxation of blood vessels and promote increased blood flow to working muscles. Beyond blood flow benefits, research shows that boosting dietary nitrates prior to training enhances muscle contraction and metabolic efficiency, meaning you can exercise at heightened intensities with less energy cost. However, until recently, we knew little about the effects of long term vs. short term nitrate supplementation on exercise performance.

A recent study published in the Journal of Strength and Conditioning Research examined the effects of long-term vs. single dosing of nitrate supplements on skeletal muscle oxygenation and cycling performance in athletic males and females. The authors reported that taking 500 mg of dietary nitrates for 15 days improved cycling time-trial performance, average power output, and average speed— while a single pre-exercise dose failed to elicit any ergogenic effects.

ACTION POINT: The researchers concluded that long-term nitrate supplementation has performance advantages over a single pre-exercise dosing. As such, strength and endurance athletes should take nitrate supplements (like beetroot extract) daily to reap the greatest performance-enhancing benefits. Based on this, we recommend taking 500 mg of high-nitrate standardized beetroot extract, 30-60 minutes before sports or exercise. On rest days take 500 mg with your morning protein shake or a few minutes prior to breakfast.

Reference:

Jo E, Fischer M, Auslander AT, Beigarten A, Daggy B, Hansen K, Kessler L, Osmond A, Wang H, Wes R. The effects of multi-day vs. Single pre-exercise nitrate supplement dosing on simulated cycling time trial performance and skeletal muscle oxygenation. J Strength Cond Res. 2017 Apr 18. doi: 10.1519/JSC.0000000000001958. [Epub ahead of print]