Influence of acute eccentric exercise on the H:Q ratio

Area of Science:

• Exercise Physiology
• Sports Science
• Muscle Physiology

Background:

• Eccentric exercise is known to induce greater muscle damage and soreness compared to concentric exercise.
• Understanding the impact of eccentric exercise on muscle strength and ratios is crucial for training program design.

Purpose of the Study:

• To investigate the effects of an acute eccentric exercise session on maximal isokinetic concentric peak torque (PT) of leg muscles.
• To determine the influence of eccentric exercise on the hamstrings-to-quadriceps (H:Q) strength ratio.

Main Methods:

• Sixteen male volunteers underwent maximal isokinetic concentric leg extension and flexion tests before and after an eccentric exercise protocol.
• The eccentric protocol involved 4 sets of 10 repetitions of leg press, leg extension, and leg curl at 120% of 1-RM.
• Measurements were taken 24-72 hours post-exercise.

Main Results:

• A significant decrease (P<0.05) in isokinetic leg flexion (13-19%) and leg extension (11-16%) peak torque was observed 24-72 hours after eccentric exercise.
• The hamstrings-to-quadriceps (H:Q) strength ratio showed no significant alteration following the eccentric exercise bout.

Conclusions:

• An acute eccentric exercise bout, using both multi-joint and single-joint exercises, leads to comparable reductions in maximal isokinetic strength for leg flexors and extensors.
• Eccentric exercise does not appear to alter the hamstrings-to-quadriceps strength ratio in the short term.