A Single Dose of Beetroot Juice not Enhance Performance during Intervallic Swimming Efforts.

Despite the numerous scientific evidence on the topic, there is no clear and consistent answer that clarifies the true effects of beetroot juice (BJ) supplementation on different types of physical performance. This study examined whether an acute intake of BJ improves swimming performance, physiological variables of anaerobic metabolism, or subjective measures during high-intensity interval exercise with incomplete rest in competitive swimmers. Eighteen competitive swimmers (nine females and nine males) participated in this cross-over randomized, placebo-controlled, double-blind and counterbalanced study. In two trials, swimmers ingested BJ (70 mL, 6.4 mmol/400 mg NO3-) or placebo (PLA) (70 mL, 0.04 mmol/3 mg NO3-) three hours before a 2×6×100 m maximal effort with 40 seconds rest between repetitions and three minutes between blocks. The 100 m times showed no differences between groups (p > 0.05), but there was an interaction between block×repetition×condition (F5 = 3.10; p = 0.046; ηp2 = 0.54), indicating that the BJ group decreased the time of the sixth repetition of block2 compared to block1 (p = 0.01). Lactate concentration showed no differences between conditions (p > 0.05), but there was a main effect of block (ηp2 = 0.60) and a block×repetition interaction (ηp2 = 0.70), indicating higher values in block2 and increasing values between repetitions in block1. The subjective scales, perception of exertion (RPE) and Total Quality Recovery (TQR), showed no effects of condition (p > 0.05), but BJ swimmers had a greater TQR in the last repetitions of each block. In conclusion, a single dose of BJ did not enhance intermittent swimming performance or modified the physiological (lactate and heart rate) or subjective (RPE and TQR) variables; although there was a possible positive effect on the exercise tolerance at the end of effort.

Physical exercise and reduction of pain in adults with lower limb osteoarthritis: a systematic review.

Osteoarthritis is a degenerative joint disease. The knee and hip joints are the most frequently affected. Treatments fall into three main categories: pharmacological, non-pharmacological, and surgical. Treatments can be applied alone or in combination. In the last few years, within the non-pharmacological category have been a growing importance of physical exercise programs aimed to reduce pain in knee and hip joints. The purpose of this review was to summarize evidence for the effectiveness and structure of exercise programs on pain in patients with hip and knee osteoarthritis. To that end, several databases were searched, retrieving 33 studies that evaluated the influence of different exercise programs on pain. These studies were grouped according to the characteristics of the exercise program: land-based intervention (strength program, Tai Chi, aerobic program), aquatic intervention (hydrotherapy), and mixed exercise programs. The main conclusions drawn were: (i) despite recommendations for the use of exercise programs as pain therapy in patients with hip and knee osteoarthritis, very few randomized clinical studies were conducted; (ii) the structure of the exercise programs (content, duration, frequency and duration of the session) is very heterogeneous; (iii) on overall, exercise programs based on Tai Chi have better results than mixed exercise programs, but without clear differences.