Does a fruit-and-vegetable fast destroy or strengthen muscles if you exercise?

Aim of the study: Anthocyanins (ACN), the sub-class of (poly)phenols responsible for the red-blue-purple pigmentation of fruit and vegetables, have gained considerable interest in sport and exercise research due to their potential to facilitate exercise recovery. A systematic literature search was performed using PubMed, The Cochrane Library, MEDLINE, SPORTDiscus and CINAHL.

Results: Strength was improved with ACN at all time points (g: 0.45-0.67). DOMS (g: -0.23) was lower 24 hours post-exercise and power was improved 24 hours (g: 0.62) and 48 hours (g: 0.57) post exercise. The CK was lower 48 hours post-exercise (g: -0.31) and there was a trend for a positive association with ACN dose (p = 0.057). This systematic review provides new data showing ACN-rich foods promote functional and subjective recovery likely due to the antioxidant and anti-inflammatory properties of ACN.

Aim of the study: Loss of skeletal muscle strength and mass (sarcopenia) is common in older adults and associated with an increased risk of disability, frailty and premature death. Finding cost-effective prevention and treatment strategies for sarcopenia for the growing ageing population is therefore of great public health interest.

Results: There is reasonably consistent epidemiological evidence suggesting benefits of higher fruits and vegetables consumption for better physical performance. Similarly, higher adherence to the Mediterranean diet is associated with beneficial effects on muscle function in observational studies. However, intervention studies are lacking. This review discusses how current evidence may inform the development of preventive and intervention strategies for optimal muscle ageing and nutritional public policy aimed at combatting sarcopenia.

Aim of the study: Muscle health is important for the functionality and independence of older adults, and certain nutrients as well as dietary patterns have been shown to offer protective effects against declines in strength and function associated with aging.

Results: Randomized controlled trials appear to suggest a critical role for dietary intake of protein in preventing sarcopenia and muscle loss, although the optimal dose and type of protein is unknown. There are some promising data regarding the role of vitamin D and sarcopenia, but it is unclear whether the dose, frequency of dose, or length of treatment impacts the efficacy of vitamin D on improving muscle mass or function. Selenium, magnesium, and omega 3 fatty acids have been studied as supplements in clinical trials and in the diet, and they appear to demonstrate a potential association with physical activity and muscle performance in older individuals. Following the Mediterranean diet and higher consumption of fruits and vegetables have been associated with improved physical performance and protection against muscle wasting, sarcopenia, and frailty.

Aim of the study: The combination of the consumption of so-called superfoods and regular exercise is a promising approach for the prevention of chronic diseases.

Results: Ten subjects participated in two crossover trials, each for 2 × 14 days: A): juice versus placebo, both without exercise, and B) juice versus placebo, both with concurrent strength and endurance training. Daily consumption of red berry fruit juice led to improvements in peripheral resistance, while no significant changes were observed in the placebo group (ANOVA: time x group, p ≤ 0.05). Participants in the juice + training group maintained their relative muscle mass, while those in the placebo + training group experienced a slight decline in their relative muscle mass (ANOVA: time x group, p ≤ 0.05). Short-term repeated consumption of a (poly)phenol-rich red berry fruit juice (in combination with physical training) presents an easy-to-apply strategy to improve health outcomes and may particularly be beneficial for vascular health and muscle mass in individuals with pre-diabetes.

Aim of the study: It has been reported that nitrate supplementation can improve exercise performance. Most of the studies have used either beetroot juice or sodium nitrate as a supplement; there is lack of data on the potential ergogenic benefits of an increased dietary nitrate intake from a diet based on fruits and vegetables.

Results: CD) were observed: (a) a significant reduction of oxygen consumption during moderate-intensity constant work-rate cycling exercise (1.178 ± 0.141 vs. 1.269 ± 0.136 L·min(-1)); (b) a significantly higher total muscle work during fatiguing, intermittent sub-maximal isometric knee extension (357.3 ± 176.1 vs. 253.6 ± 149.0 Nm·s·kg(-1)); (c) an improved performance in Repeated Sprint Ability test. These findings suggest that a high-nitrate diet could be a feasible and effective strategy to improve exercise performance.

Aim of the study: To investigate the association between fruit and vegetable intake and lean mass, muscle strength, and functional capacity in kidney transplant patients (KTPs).

Results: Fruit intake (servings) was positively associated with lean mass (kg) (β = 0.522; P = .024), handgrip strength (kg) (β = 0.874; P = .012), and walking speed (m/s) (β = 0.021; P = .014). However, no significant association was observed between fruit intake and performance on the five times sit-to-stand test. Vegetable intake was not significantly associated with any of the muscle-related parameters evaluated. Fruit, but not vegetable, intake was positively associated with lean mass, handgrip strength, and 4-m walking speed in KTPs.