Combat sports like jiu-jitsu, judo, and wrestling all involve grappling, which in turn requires a lot of forearm muscle strength.
Given the importance of improving grip strength for these types of athletes, the study set out to determine whether ingesting a single dose of beetroot-based gel improved muscle strength and muscle oxygen saturation.
The authors hypothesized that a single dose of beetroot-based gel supplement would improve muscle strength and muscle oxygenation in combat sport trained athletes.
To test their theory, the randomized, crossover, double-blind study included 14 healthy male combat sport who had at least 5 years of frequent combat sports training experience (training at least five times per week), with 15 hours or more of training per week.
Athletes were excluded if they had any disease, such as diabetes mellitus, kidney and lung failure, cardiovascular disease and/or skeletal muscle, tendon and bone injuries which compromised handgrip exercise, and usage of antioxidants, amino acids, pre-working supplementation, or androgenic anabolic steroids.
All participants came to the laboratory on three occasions. The first visit was used to explain the experimental procedures, take measurements, and familiarize subjects with rhythmic handgrip exercise. The subjects were also randomized and given either 100g of beetroot-based nutritional gel or the control, which was a nitrate-depleted gel.
On the second and third visit, maximal forearm muscle isometric strength was measured followed by a single dose of the beetroot gel or the placebo. About two hours after the supplementation, three sets of rhythmic handgrip exercise was performed.
A near-infrared spectroscopy device was also used to assess the forearm muscle oxygen saturation during exercise and recovery. The forearm muscles were assessed at the baseline and 20 minutes after handgrip exercise in order to measure the muscle strength recovery.
Overall, the researchers found that a single oral dose of beetroot-based gel does not improve muscle oxygenation parameters. However, it does speed up handgrip isometric strength recovery in recreational combat sports athletes.
The researchers pointed out that the high-nitrate beetroot gel supplementation attenuated the decline of handgrip strength after a fatiguing exercise and it did not induce changes in muscle oxygen saturation or in the time-to-fatigue during handgrip exercise.
One noted limitation was that although all participants were instructed not to take antioxidants, amino acids, and/or pre-workout supplements, there was no way to guarantee they had adhered to the nutritional and supplement restrictions.
The authors conclude that a single dose of high-nitrate beetroot-based gel accelerated maximal forearm muscle strength recovery 20 minutes after exhaustive handgrip exercise in recreational combat athletes. “However, the exercise time until fatigue and muscle O2 saturation during exercise and exercise recovery were not improved. Therefore, a single dose of beetroot gel supplementation may be considered a good nutritional strategy to attenuate declining forearm muscle strength caused after several rounds of combat sports performed intensively or without adequate recovery time.”
Source: Biology of Sport
2020;37(1):93-99 DOI: https://doi.org/10.5114/biolsport.2020.92518
“A single oral dose of beetroot-based gel does not improve muscle oxygenation parameters, but speeds up handgrip isometric strength recovery in recreational combat sports athletes”
Authors: G. Vieira et al.