Effect of High-Intensity Interval Treadmill Exercise on Subsequent Lower and Upper Limb Strength Performance

Area of Science:

• Exercise Physiology
• Sports Science
• Biomechanics

Background:

• High-intensity interval training (HIIT) is a popular training method.
• Understanding the impact of pre-fatigue from HIIT on subsequent strength performance is crucial for training program design.

Purpose of the Study:

• To investigate the acute effects of a treadmill-based high-intensity interval protocol on subsequent upper and lower body strength exercise performance.
• To compare the impact on lower body (half-squat) versus upper body (bench press) strength.

Main Methods:

• Sixteen young men performed randomized conditions: control sessions (half-squat or bench press only) and experimental sessions (treadmill HIIT followed by half-squat or bench press).
• Strength performance was assessed by the number of repetitions to failure at 80% of one-repetition maximum (1RM).
• Physiological markers including heart rate (HR) and blood lactate concentration ([lac]) were measured.

Main Results:

• Fewer repetitions were completed in experimental sessions compared to control sessions for both exercises (p < .001).
• The reduction in repetitions was significantly greater for the half-squat compared to the bench press (p = .018).
• Heart rate was elevated post-exercise in HIIT conditions, and blood lactate increased significantly after HIIT followed by half-squat (p = .003).

Conclusions:

• Previous high-intensity interval running acutely impairs subsequent strength exercise performance.
• The negative impact on strength performance is more pronounced for lower body exercises than for upper body exercises.