Neuromuscular Fatigability Associated with Different Pacing Strategies During an Ultra-Endurance Pull-Up Task: A Case...

Area of Science:

• Exercise Physiology
• Sports Science
• Neuromuscular Function

Background:

• Neuromuscular fatigability is well-documented after endurance activities like running and cycling.
• However, its characteristics during ultra-endurance upper body tasks remain unexplored.
• This study addresses this gap in preparation for a world record attempt.

Purpose of the Study:

• To compare the effects of three distinct pacing strategies on neuromuscular fatigability during an ultra-endurance pull-up task.
• To identify the optimal pacing strategy for minimizing fatigue and maximizing performance in prolonged upper body exercise.
• To inform the strategy for an upcoming world record attempt.

Main Methods:

• Three participants undertook three independent sessions, performing 1980 pull-ups within 6 hours using different pacing strategies: fast pace with long recovery (FL), fast pace with multiple short recoveries (FMS), and slow pace with no recovery (SN).
• Measurements included elbow flexion maximal voluntary contraction (MVC) force, grip strength, peripheral fatigue, biceps brachii electromyography, heart rate, perceived effort, and arm muscle pain.
• Data were collected every 330 pull-ups and during recovery periods.

Main Results:

• Maximal voluntary contraction (MVC) force declined rapidly in all conditions, with the most significant decrease observed in the FL strategy (-29.1%).
• The FL strategy also showed the greatest reduction in potentiated single twitch (-75.0%) and high-frequency doublet forces (-63.3%) after the initial set.
• Higher heart rate, perceived effort, and muscle pain were reported throughout the task in the FL condition compared to FMS and SN.

Conclusions:

• A slow, continuous pacing strategy (SN) is superior for ultra-endurance pull-up performance, leading to less neuromuscular fatigue and faster recovery.
• The fast pace, long recovery (FL) strategy resulted in the most profound neuromuscular fatigue and slowest recovery of MVC force.
• The findings recommend a continuous, slower-paced approach for ultra-endurance upper body events to optimize performance and manage fatigue effectively.