THE EFFECTS OF ACUTE BEETROOT JUICE INGESTION ON DIURNAL VARIATION IN MAXIMAL ISOMETRIC AND VERTICAL JUMP PERFORMANCE
Jillian Hart, Kathryn Hoppers, Rebecca R. Rogers, Tyler D. Williams, Christopher G. Ballmann, FACSM. Samford University, Birmingham, AL.
BACKGROUND: Diurnal fluctuations in exercise ability may confound training and competition performance during morning hours. Beetroot juice (BRJ) is a rich source of dietary nitrate which has been reported to increase muscle force production and blood flow to skeletal muscle. Our lab has recently shown that BRJ attenuates morning-associated decrements in sprint performance, but it remains unknown if this translates to short explosive movements. Therefore, the purpose of this study was to investigate the effects of BRJ on time-of-day changes in isometric mid-thigh pull (IMTP) and countermovement vertical jump (CMJ) performance. METHODS: Physically active males participated in three counterbalanced exercise trials under the following conditions: 1) Morning-Placebo (AM-PL), 2) Morning-BRJ (70 mL; 400 mg NO3), and 3) Afternoon-Control (PM). For each AM trial, participants consumed their respective treatment 2 hours before exercise while no treatment was given for PM. Participants completed 3 ´ Isometric mid-thigh pull tests maximally using an IMTP rig equipped with an immovable bar and ground force plates. For each IMTP attempt, participants maximally pulled for 3 seconds. Following this, participants completed 3 ´ CMJ without arm swing on ground force plates. All attempts for IMTP and CMJ were separated by 2 minutes of recovery. Trials were separated by a minimum of 48 hours. RESULTS: Findings for IMTP showed no differences for net peak force (p= 0.651) or rate of force development (p= 0.438) between treatments. Furthermore, jump height (p= 0.894), peak propulsive force (p= 0.780), and take off velocity (p= 0.884) were not altered by treatment. CONCLUSION: These results suggest that BRJ does influence time-of-day performance for short explosive movements.
Hart, J; Hoppers, K; Rogers, RR; Williams, TD; and Ballmann, FACSM, C
"THE EFFECTS OF ACUTE BEETROOT JUICE INGESTION ON DIURNAL VARIATION IN MAXIMAL ISOMETRIC AND VERTICAL JUMP PERFORMANCE,"
International Journal of Exercise Science: Conference Proceedings: Vol. 16:
2, Article 165.
Available at: https://digitalcommons.wku.edu/ijesab/vol16/iss2/165