Editor-in-Chief JEPonline The Marc Pro TM Device Improves Muscle Performance and Recovery from Concentric and Eccentric Exercise Induced Muscle Fatigue in Humans: A Pilot Study

Exercise Induced Muscle Fatigue in Humans: A Pilot Study. JEPonline 2011;14(2):55-67. To date, a product or routine that consistently relieves delayed onset muscle soreness (DOMS) caused by eccentric exercise has yet to be identified. Our latest 56 research results indicate that a new device called Marc Pro™ (MPD) significantly improves muscle recovery and muscle endurance from combined concentric and eccentric exercise in healthy recreational exercisers. In the first study, 14 subjects (no prior soreness upon study entry) performed strength training activity (leg extension exercise with eccentric emphasis) to produce DOMS in the quadriceps muscles. All participants received one-hour of MPD stimulation on the right leg only following the exercise session whereby each participant served as their own control. One day later, assessment of muscle soreness revealed significantly less discomfort in the right leg (MPD) than in the left leg (no MPD) in all subjects and in responders, respectively (p < 0.008; p < 0.002 ). The number of repetitions completed with the right leg (MPD) was significantly greater than the number of repetitions completed with the left leg (no MPD) in all subjects and in responders, respectively (p < 0.03; p < 0.008). In the second experiment, 13 subjects (no prior soreness upon study entry) utilized a modestly challenging uphill/downhill hike to produce DOMS in the quadriceps muscles. Following the hike the subjects' right leg received MPD stimulation for 60 minutes, whereas the left leg received no MPD application. Reported soreness was significantly less in the right leg (MPD) than in the left leg (no MPD) in all participants and in responders, respectively (p < 0.0008; p < 0.0002). These results suggest that MPD stimulation results in a significant reduction in DOMS following strenuous unaccustomed eccentric exercise and significantly greater muscle endurance performance, as measured by leg extension repetitions. Investigation of Marc Pro TM in a larger population is underway and must await confirmation

Recovery in Soccer

International audienceIn the formerly published part I of this two-part review, we examined fatigue after soccer matchplay and recovery kinetics of physical performance, and cognitive, subjective and biological markers. To reduce the magnitude of fatigue and to accelerate the time to fully recover after completion, several recovery strategies are now used in professional soccer teams. During congested fixture schedules, recovery strategies are highly required to alleviate post-match fatigue, and then to regain performance faster and reduce the risk of injury. Fatigue following competition is multifactorial and mainly related to dehydration , glycogen depletion, muscle damage and mental fatigue. Recovery strategies should consequently be targeted against the major causes of fatigue. Strategies reviewed in part II of this article were nutritional intake, cold water immersion, sleeping, active recovery, stretching , compression garments, massage and electrical stimulation. Some strategies such as hydration, diet and sleep are effective in their ability to counteract the fatigue mechanisms. Providing milk drinks to players at the end of competition and a meal containing high-glycaemic index carbohydrate and protein within the hour following the match are effective in replenishing substrate stores and optimizing muscle-damage repair. Sleep is an essential part of recovery management. Sleep disturbance after a match is common and can negatively impact on the recovery process. Cold water immersion is effective during acute periods of match congestion in order to regain performance levels faster and repress the acute inflammatory process. Scientific evidence for other strategies reviewed in their ability to accelerate the return to the initial level of performance is still lacking. These include active recovery, stretching, compression garments, massage and electrical stimulation. While this does not mean that these strategies do not aid the recovery process, the protocols implemented up until now do not significantly accelerate the return to initial levels of performance in comparison with a control condition. In conclusion, scientific evidence to support the use of strategies commonly used during recovery is lacking. Additional research is required in this area in order to help practitioners establish an efficient recovery protocol immediately after matchplay, but also for the following days. Future studies could focus on the chronic effects of recovery strategies, on combinations of recovery protocols and on the effects of recovery strategies inducing an anti-inflammatory or a pro-inflammatory response