Short term creatine loading improves strength endurance even without changing maximal strength, RPE, fatigue index,...

Area of Science:

• Sports Science
• Exercise Physiology
• Nutritional Biochemistry

Background:

• Creatine is a popular supplement among athletes aiming to boost strength and muscle mass.
• Understanding creatine's specific effects on different aspects of strength performance is crucial for optimizing training protocols.

Purpose of the Study:

• To investigate the impact of a five-day creatine supplementation regimen on maximal strength and strength endurance in trained men.
• To assess secondary physiological and perceptual responses, including blood lactate, rate of perceived effort, fatigue index, and mood state.

Main Methods:

• A double-blind, placebo-controlled, randomized crossover study involving twelve strength-trained men.
• Participants underwent a five-day supplementation period with either creatine (20g creatine + 10g maltodextrin) or a placebo (20g starch + 10g maltodextrin).
• Measurements included maximal strength (1RM bench press), strength endurance (sets to failure at 70% 1RM), blood lactate, RPE, fatigue index, and mood state, assessed pre- and post-supplementation.

Main Results:

• Creatine supplementation significantly increased the number of repetitions performed to concentric failure (Δ = +3.4 reps, p = 0.036) and total work completed (Δ = +199.5 arbitrary units, p = 0.038) compared to placebo.
• No significant changes were observed in maximal strength, blood lactate levels, rate of perceived effort, fatigue index, or mood state in either the creatine or placebo group.
• The effect size for increased repetitions and total work in the creatine group was moderate (g = 0.53 and g = 0.52, respectively).

Conclusions:

• A five-day creatine loading phase can enhance muscular endurance, enabling individuals to perform more repetitions and generate greater total work during resistance exercise.
• Short-term creatine supplementation does not appear to significantly improve maximal strength or alter key physiological and perceptual fatigue markers in strength-trained individuals.
• These findings suggest that creatine's primary benefit within a short loading period may lie in improving the capacity for sustained muscular effort rather than peak force production.