Acute acetaminophen ingestion improves performance and muscle activation during maximal intermittent knee extensor...

Area of Science:

• Exercise Physiology
• Sports Science
• Pharmacology

Background:

• Acetaminophen is a common analgesic with emerging evidence suggesting potential ergogenic benefits.
• Understanding the physiological mechanisms behind acetaminophen's effect on exercise performance is crucial.

Purpose of the Study:

• To investigate how acute acetaminophen ingestion affects neuromuscular fatigue during high-intensity exercise.
• To explore the physiological mechanisms by which acetaminophen may blunt muscle fatigue development.

Main Methods:

• Thirteen active males performed repeated maximal voluntary contractions (MVCs) of knee extensors.
• Neuromuscular fatigue was assessed via peripheral nerve stimulation and surface electromyography.
• Critical Torque (CT) and voluntary muscle activation were measured post-acetaminophen or placebo ingestion.

Main Results:

• Acetaminophen ingestion resulted in greater mean torque and critical torque compared to placebo.
• Muscle activation, measured by electromyography amplitude, was better preserved with acetaminophen.
• No significant differences were observed in voluntary activation or potentiated twitch decline between conditions.

Conclusions:

• Acute acetaminophen ingestion appears to be ergogenic, potentially by increasing critical torque.
• Acetaminophen may enhance high-intensity exercise capacity by preserving muscle activation and blunting fatigue.