Effects of Beetroot Juice on Recovery of Muscle Function and Performance between Bouts of Repeated Sprint Exercise

Abstract

This study examined the effects of beetroot juice (BTJ) on recovery between two repeated-sprint tests. In an independent groups design, 20 male, team-sports players were randomized to receive either BTJ or a placebo (PLA) (2 × 250 mL) for 3 days after an initial repeated sprint test (20 × 30 m; RST1) and after a second repeated sprint test (RST2), performed 72 h later. Maximal isometric voluntary contractions (MIVC), countermovement jumps (CMJ), reactive strength index (RI), pressure-pain threshold (PPT), creatine kinase (CK), C-reactive protein (hs-CRP), protein carbonyls (PC), lipid hydroperoxides (LOOH) and the ascorbyl free radical (A•−) were measured before, after, and at set times between RST1 and RST2. CMJ and RI recovered quicker in BTJ compared to PLA after RST1: at 72 h post, CMJ and RI were 7.6% and 13.8% higher in BTJ vs. PLA, respectively (p < 0.05). PPT was 10.4% higher in BTJ compared to PLA 24 h post RST2 (p = 0.012) but similar at other time points. No group differences were detected for mean and fastest sprint time or fatigue index. MIVC, or the biochemical markers measured (p > 0.05). BTJ reduced the decrement in CMJ and RI following and RST but had no effect on sprint performance or oxidative stress.

Alterations in redox homeostasis following repeated sprint training

“…The level of CK obtained at the pre-and posttraining time points suggests that a high muscle damage occurs as a result of the RS exercise. This was consistent with the previously published studies in which similar CK values of 592 U/L were registered (Clifford, et al, 2016); however, even much higher values of 776 U/L (Howatson & Milak, 2009) and 1120.7 U/L (Woolley, Jakeman, & Faulkner, 2014) were also reported after different running RS exercises. Interestingly, much lower CK values of 230.6 U/L (Jówko, et al, 2015) and 166 U/L (Bloomer, et al, 2006) were reported in studies investigating cycling RS exercises, which was probably caused by a different muscle action utilized in cycling versus running.…”

“…Namely, peak CK values are usually reached 24 hours after highintensity sport activities in which RS sequences are frequently executed (Silva, et al, 2018). Interestingly, 1-hour post-exercise CK values, reported in some of the above-cited studies, were 362 U/L (Clifford, et al, 2016) and 376 U/L (Woolley, et al, 2014), which was similar to the values obtained in the present study. It can be implicated that the level of muscle damage in our study was even greater, but the measurement time point prevented us from capturing the peak CK values.…”

“…Indeed, the RS exercises analyzed in our study were comprised of two sets of six 10 × 20-m sprinting and three sets of 10 × 20-m sprinting prior to the initial and the final measurement, respectively, while the 40 × 15 m (Woolley, et al, 2014), 15 × 30 m (Howatson & Milak, 2009) and 20 × 30 m (Clifford, et al, 2016) RS protocols were used in other studies. Since those RST protocols were comprised of longer sprint distances ran within a single set (Clifford et al, 2016;Howatson & Milak, 2009) and even had a greater number of repetitions (Woolley, et al, 2014), a greater metabolic and neuromuscular stress could be expected in those studies (Buchheit & Laursen, 2013b), which could than induce a greater muscle damage. However, different measurement time points also contributed to dissimilar CK values as the blood drawing procedure was performed within the first hour post-exercise in this study, while the reported peak CK values in other studies were obtained 24 hours post-exercise.…”

“…Namely, a great anaerobic demand, stemming from the repeated all-out sprints, and increasing aerobic contribution throughout a bout, as the sprints are done with very little recovery in between, may increase the production of ROS and cause OS. Previous studies have reported conflicting results in which an increase (Clifford, et al, 2016;Escobar, et al, 2009;Jówko, Długołęcka, Makaruk, & Cieśliński, 2015;Peart, et al, 2013), no change (Bloomer, et al, 2006;Clifford, et al, 2016;Farney, et al, 2012;Leeder, et al, 2014) and even a decrease (Goods, et al, 2016) in OS markers were observed following an acute repeated sprint (RS) exercise. Similarly, an increase (Escobar, et al, 2009;Jówko, et al, 2015), no change (Peart, et al, 2013) and a decrease (Farney, et al, 2012) in parameters of antioxidant capacity/activity were observed after acute RS exercises.…”

The benefits and risks of beetroot juice consumption: a systematic review

“…Furthermore, quicker recovery was observed after consumption of BRJ, which resulted in enhanced recovery in counter-movement jumps, reactive strength index and repeated sprint test. This study also found that no mean differences were observed for fastest sprint time or fatigue index after BRJ consumption (Clifford, Bell, et al 2016;Clifford, Berntzen, et al 2016). Some studies have shown a reduction in muscle pain and fatigue associated with exercise induced muscle damage and reduced after with BRJ supplementation Husmann et al 2019).…”