EMS Recovery Effects in Sport Climbing

Sport climbing places high and repetitive demands on the forearm muscles, which are required to sustain repeated gripping and pulling actions with limited recovery time. During prolonged or repeated climbing bouts, local muscular fatigue can accumulate, potentially affecting endurance and movement quality. Competitive climbers are particularly exposed to these demands, as competitions often involve multiple rounds performed within the same day with short rest intervals. For this reason, recovery strategies that can be applied between climbing efforts are of practical relevance in both training and competition settings.

Electrical muscle stimulation (EMS) is a recovery modality that delivers low-intensity electrical impulses to skeletal muscle, producing rhythmic, involuntary contractions. EMS has been used in various sport and rehabilitation contexts as a low-effort method that can be applied without additional mechanical load. However, its application as an inter-bout recovery strategy in sport climbing has not been sufficiently characterized under controlled, climbing-specific conditions.

This study is designed as a randomized crossover trial to compare EMS-based recovery (EMSr) and passive recovery (PASr) following a standardized climbing fatigue protocol. Advanced male sport climbers will participate in two experimental sessions separated by a one-week washout period. In each session, participants will complete the same climbing fatigue protocol, followed by one of the two recovery conditions, with the order of recovery methods randomized.

The fatigue protocol consists of repeated climbing bouts performed on a standardized training wall using a fixed route of defined difficulty. This protocol is intended to elicit localized forearm fatigue under reproducible conditions. Following completion of the fatigue protocol, participants will undergo either EMS applied to the forearm muscles for a fixed duration or passive recovery involving seated rest without additional intervention.

Climbing-related performance measures, muscular endurance tasks, cardiovascular responses, and ratings of perceived exertion will be recorded at predefined time points before and after the recovery period. These measurements are included to characterize physiological and performance-related responses associated with each recovery condition.

The crossover design allows each participant to serve as their own control, thereby reducing inter-individual variability and enabling a direct comparison of recovery approaches under standardized conditions.

Inclusion criteria

• Male climbers aged 30-36 years.
• At least 3 years of continuous climbing experience, training 3-4 times per week.
• Ability to climb at least IRCRA grade 15 (French 6a) routes.
• In good general health and able to safely perform high-intensity climbing.
• Willing to provide written informed consent and follow study instructions.

Exclusion criteria

• Participation in other sports with high training loads that could interfere with the study.
• Any injury, medical condition, or musculoskeletal problem that limits climbing performance.
• Use of medications or supplements that could affect muscle performance or recovery.
• Inability to comply with study procedures, including the climbing and recovery protocols.