Improvement of Functional Ankle Properties Following Supplementation with Specific Collagen Peptides in Athletes with Chronic Ankle Instability.

Following an initial ankle sprain it is not unlikely that chronic ankle instability (CAI) will develop. CAI is associated with impaired perceived functional and mechanical properties of the ligaments. Nutritional supplementation with collagen peptides has been shown to improve the functional and mechanical properties of the connective tissue. The purpose of this study was to investigate the effectiveness of specific collagen peptide supplementation (SCP) to improve ankle stability in athletes with CAI. 50 male and female athletes with CAI completed a randomized, double-blinded and placebo-controlled study with a daily oral administration of either 5 g SCP or 5 g placebo (Maltodextrin) over a period of six months. Both, the Cumberland Ankle Instability Tool (CAIT) and the German version of the Foot and Ankle Ability Measure (FAAM-G) were used to measure the subjective perceived function of the ankle. Additionally, the mechanical stability was determined by measuring the ankle stiffness by an ankle arthrometer. Finally, a three-month follow-up was performed. ANOVA analysis indicated that the subjective ankle stability was improved in both the CAIT (p < 0.001) and the FAAM-G (p < 0.001) following SCP supplementation compared with placebo. No significant changes between the groups were detected in the results of the ankle arthrometer. After six month the subjective report of the ankle stability function significantly improved and the three month follow-up revealed a significant decline in the number of ankle joint injuries (p < 0.05). These data support the concept that specific collagen peptide supplementation in athletes with chronic ankle instability results in significant improvements in subjective perceived ankle stability. The reduction in the re-injury rate of ankle sprains in the follow-up period suggests that these findings have clinical relevance.

Acute effects of blood flow restriction on exercise-induced free radical production in young and healthy subjects.

The main purpose of this study was to investigate the acute local and systemic effects of low-load resistance exercise (30% 1RM) with partial vascular occlusion on exercise-induced free radical production and to compare these effects with other established training methods. Fifteen young and healthy males (25 ± 3 years) performed the following four sessions in a counterbalanced order on separate days: low-load resistance exercise (LI: 30% 1RM), low-load resistance exercise with blood flow restriction (LIBR: 30% 1RM), high-load resistance exercise (HI: 80% 1RM) and an additional session without exercise but blood flow restriction only (BR). Blood samples were obtained 15 min prior to and immediately after exercise sessions from the right index finger and first toe. To analyze concentrations of reactive oxygen species (ROS), electron paramagnetic resonance (EPR) spectroscopy was used. Additionally, mitochondrial ROS production was measured by adding inhibitors of electron transport chain complex III. There was an increased systemic ROS generation after the LIBR session from 0.837 ± 0.093 to 0.911 ± 0.099 µmol/l/min. However, no local or systemic time × condition interaction was detected for ROS production. Regarding mitochondrial ROS production, results were not different between the conditions. Although the low-load resistance exercise session with partial vascular occlusion elicited systemic increases of ROS production, no significant changes were seen on a local level. We assume that this ROS concentration might not be high enough to induce cellular damage but is rather involved in muscle remodulation. However, this needs to be confirmed by future research.