Effects of submaximal and supramaximal accentuated eccentric loading on mass and function.

Area of Science:

• Exercise Physiology
• Sports Science
• Muscle Physiology

Background:

• Eccentric-overload (EO) training utilizes loads relative to eccentric force capacity.
• Prescribing eccentric loads based on concentric one-repetition maximum (1-RM) is common due to individual variability.
• Investigating submaximal vs. supramaximal EO training is crucial for optimizing training protocols.

Purpose of the Study:

• To compare the effects of submaximal (90% 1-RM) and supramaximal (120% 1-RM) eccentric-overload training.
• To assess changes in lean mass, anabolic hormonal responses, and muscle function.
• To determine the necessity of supramaximal loads for enhancing strength and performance.

Main Methods:

• 27 physically active students underwent 10 weeks of dominant leg isotonic training twice weekly.
• Two groups performed eccentric phases at either 90% (SUB) or 120% (SUPRA) of 1-RM, with a 30% 1-RM concentric load.
• Measurements included lean mass, hormonal responses (IGF-1, IL-6), 1-RM, isometric contractions, endurance, power, and jump height.

Main Results:

• Both SUB and SUPRA groups showed significant increases in maximal voluntary isometric contractions, muscle endurance, muscle power at 40% 1-RM, lean mass, IGF-1, and IL-6.
• The SUPRA group demonstrated significantly greater increases in 1-RM strength and vertical jump height compared to the SUB group.
• Muscle power at higher intensities also increased in the SUB group, but without significant differences between groups.

Conclusions:

• Ten weeks of eccentric-overload training with either submaximal or supramaximal eccentric loads induces comparable improvements in muscle function and lean mass.
• Supramaximal eccentric loading may be more effective for enhancing 1-RM strength.
• The benefits of supramaximal eccentric loads may not be essential for healthy, active individuals seeking general strength and muscle adaptations.