1. Montmorency Tart Cherry Concentrate Attenuates Inflammatory Response and Muscle Function Decline Following High-intensity Stochastic Cycling
Phillip G. Bell1 , Ian H. Walshe2, Gareth W. Davison (FACSM)3 and Glyn Howatson1 (FACSM)
1Faculty of Health and Life Sciences, Northumbria University, Newcastle, UK; 2University of Stirling, UK; 3University of Ulster, UK
Venous blood samples were taken pre-supplementation on day 1 , immediately pre and post trial on day 5 and on days 5-8 for analysis of inflammatory indices (IL-6, IL-8, TNF-α and hsCRP).
Abstract
Introduction: The use of functional foods in exercise recovery is of growing interest; in particular, Montmorency tart cherries have received increasing attention because of their high antioxidative and anti-inflammatory potential. To date, positive results using Montmorency cherry concentrate (MC) have only been demonstrated following mechanically strenuous exercise that incorporates high intensity or volume eccentric contractions. In this study, we examine the efficacy of MC as a recovery aid, following an exercise stress (cycling) with a high metabolic challenge and very little mechanical stress. PURPOSE: To determine the effect of Montmorency cherry concentrate on recovery of muscle function and inflammation following strenuous cycling activity. METHODS: Sixteen trained male cyclists (mean ± SD age, height, mass, VO2peak was ± 8.1 yr; ± 6.7 cm, 76.5 ± 9.2 kg, 60.7 ± 11.3 mL.kg-1.min-1, respectively) completed baseline performance tests of isometric quadriceps strength (knee flexion using strain gauge [MVIC]) and 6 second maximal power cycling sprint. Participants were equally and randomly assigned to either a MC or Placebo (PLA) group and completed 8 days of supplementation (2 x 30 mL per 24 h) whilst adhering to dietary and exercise restrictions. On day 5 participants completed a high-intensity stochastic cycling task lasting 109 minutes and returned at the same time on days 6-8 to repeat baseline performance tests. Venous blood samples were taken pre-supplementation, pre-exercise, post-exercise, 1, 3, 5, 24, 48 and 72 h for analysis of inflammatory markers (IL-6, IL-8, TNF-α and hsCRP). Repeated-measures ANOVA’s were conducted for all variables with post-hoc comparisons where necessary to examine differences between conditions (α = 0.05). RESULTS: MVIC decline was attenuated in the MC group compared to PLA at 48 h (12.1%, p<0.05) and 72 h (21.5%, p<0.05). Additionally, main effects (p<0.05) for group were identified for IL-6 and hsCRP with lower responses in MC vs. PLA. No significant differences were found for other performance or inflammatory variables. CONCLUSION: These data, for the first time show that MC supplementation prior to, and following a metabolic biased challenge facilitates recovery as assessed through improved restoration of MVIC and reduced inflammatory response in trained cyclists.
Fig. 3. Interleukin-6 responses (% of baseline) to MC and PLA. *Group effect (P < 0.05), values are mean ± SD.
Fig. 1. Schematic of testing protocol. All visits (excl. Visit 1) were conducted at 8am following an overnight fast.
Blood sampling ( + performance measures)
Supplementation period – 2 x 30 mL per day
Dietary restriction period
Introduction
Montmorency cherry concentrate (MC) has been shown to attenuate declines in muscle function following maximal eccentric contractions and marathon running [1,2]. Additional reductions in inflammatory responses to exercise have been demonstrated [1,3]. Despite this, no data has demonstrated the effects of MC supplementation on muscle recovery and inflammation following a exclusively metabolic challenge.
Results
Group and interaction (P < 0.05) effects were found for MVIC; group effects were found for IL-6 and hsCRP (P < 0.05) ; time effects were found in IL-8 and TNF-α (P < 0.05).
MVIC decline was attenuated in the MC group with peak and mean differences of 21% and 14% between groups. Interaction effects were found at 48 and 72 h (Fig 2).
The response of IL-6 to the trial was dampened in the MC group, a peak difference of 1.4 pg.mL-1 was found immediately post-trial (Fig 3).
hsCRP remained depressed across all time points following the supplementation phase excluding 24 h, whilst the PLA group showed opposing responses. Peak group differences of 76% occurred at 24 h (Fig 4).
Fig. 4. hsCRP responses (% of baseline) to MC and PLA. *Group effect (P < 0.05), values are mean ± SD.
Aim
Conclusions
Identify the effects of MC supplementation on muscle function and inflammation following physiological stress induced exclusively through metabolic pathways (prolonged, high-intensity stochastic cycling).
These data are the first to demonstrate improved recovery of muscle function with MC following stress induced exclusively through metabolic pathways and support previous literature demonstrating similar effects from mechanical muscle damage. Additionally, the attenuated inflammatory response suggests such improvements in recovery may be due to a reduction in damage caused by inflammatory processes. Application of this may be suited to scenarios where accelerated recovery is desirable, such as when there is a requirement for consecutive days performance.
Methods
Sixteen trained male cyclists (mean ± SD age, height, mass, VO2peak was 30 ± 8 yrs; ± 6.7 cm, 76.5 ± 9.2 kg, 61.6 ± 10.4 mL.kg-1.min-1, respectively) volunteered to participate.
Participants were randomly assigned to either an MC or isocaloric placebo (PLA) group and completed 8 days of supplementation (2 x 30 mL per 24 h) whilst abiding to set dietary and exercise restrictions.
Maximal voluntary isometric contraction (MVIC) was assessed via strain gauge prior to supplementation and on days 6, 7 and 8.
On 5 participants completed a high-intensity stochastic cycling task lasting 109 minutes.
A schematic of the experimental is shown in Fig 1. $ $
References
1. Connolly, D.A.J., McHugh, M. and Padilla-Zakour, O.I. Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage. British Journal of Sports Medicine 2006, 40 (8),
2. Howatson, G.; McHugh, M.P.; Hill, J.A.; Brouner, J.; Jewell, A.P.; Van Someren, K.A.; Shave, R.E.; Howatson, S.A. Influence of tart cherry juice on indices of recovery following marathon running. Scandinavian Journal of Medicine and Science in Sports 2010, 20, 843–852.
3. Bell, P.G., Walshe, I.H., Davison, G.W., Stevenson, E. and Howatson, G. Montmorency Cherries Reduce the Oxidative Stress and Inflammatory Responses to Repeated Days High-Intensity Stochastic Cycling. Nutrients 2014, 6,
Fig. 2. Maximum voluntary isometric contraction responses (% of baseline) to MC and PLA. *Group effect (P < 0.05). $Interaction effect (P < 0.05), values are mean ± SD.