Research on beetroot juice has traditionally focused on its effects in endurance athletes. But a new study has suggested bodybuilders and strength athletes may stand to benefit from the nature’s purple potion too.
Researchers from the UK and South Africa combined to test the effect of a commercial beetroot juice concentrate on muscle damage resulting from counter movement (or drop) jumps.
The study included a high and low dose group together with a placebo. Rather than just focusing on the nitrate content of the drink, which is the norm for studies on beetroot, the researchers also measured phenolic content and special compounds called betanin and betaxanthins as well as nitrate. Because muscle damage resulting from eccentric exercise is mediated in part by inflammatory responses, the thinking was that antioxidant phenolic compounds that are naturally high in beetroot might play an important part in addition to nitrate.
The muscle-damage routine consisted of 100 ‘drop jumps’ from a 60cm high steel box. To perform the drop jumps, participants were instructed to drop off the box and land on two feet and immediately descend to a ~90O knee angle followed by a maximal effort vertical jump. Each jump was separated by a 10 s interval and each 20 jumps by a 2 min rest period (i.e. 5 sets of 20 repetitions). This type of routine is renowned for producing very sore legs, especially if un-accustomed, as was the case for each of the participants.
After the protocol each participant was given several doses of beetroot juice or placebo depending on which group they were randomly allocated to. The high-dose group received 3 shots the day of the exercise as well as two doses per day for the two days following. Each serving consisted of 250ml of a concentrated beetroot juice beverage that had the equivalent of 3 average-sized beetroots, which equated to ~250mg of nitrate. The low dose group consumed a half serve (i.e. 125ml) of this same drink, while the placebo was simply a commercial low fruit (<1 %) squash with negligible phytochemical and nitrate content.
The researchers measured a bunch of markers indicative of muscle damage as well as inflammation, but also assessed the subjects for their ability to perform exercises such as the countermovement jump, which stressed the damaged leg muscles.
When analysing results, the researchers found that subjects receiving the high dose beetroot recovered their countermovement jump capacity significantly quicker that placebo subjects. In addition, muscle soreness measured via a pressure pain threshold unit improved significantly faster in both the high and low-dose groups 24, 48 and 72 h post-exercise. With only the high dose group experiencing improved countermovement jump ability, it suggests that high-dose beetroot might be more beneficial for preventing acute losses in muscle function.
This study suggests that in addition to endurance athletes, guys and girls going hard at the gym might benefit from beetroot supplementation. And with previous research showing beetroot can improve muscle-contractile function and high-intensity exercise capacity, it would seem beetroot juice is shaping as a no-brainer supplement for athletes of all kinds.
Clifford T, et al. The effects of beetroot juice supplementation on indices of muscle damage following eccentric exercise. Eur J Appl Physiol. DOI 10.1007/s00421-015-3290-x