Effects of trunk extensor eccentric exercise on lipid profile and glycaemic response

Area of Science:

• Exercise Physiology
• Muscle Physiology
• Metabolic Health

Background:

• Previous research focused on limb muscle eccentric contractions, neglecting trunk muscles.
• Understanding trunk extensor responses to eccentric exercise is crucial for functional training and injury prevention.

Purpose of the Study:

• To compare functional and metabolic changes following eccentric versus concentric trunk extensor exercises.
• To investigate physiological responses to eccentric trunk muscle contractions.

Main Methods:

• A randomized crossover study involving 10 men performing 50 maximal voluntary concentric and eccentric trunk extensor contractions.
• Measurement of paraspinal muscle activity, muscle soreness, function, blood lipids, and glycemic response pre- and post-exercise at various time points.

Main Results:

• Eccentric contractions showed higher paraspinal muscle activity (lumbar multifidus, iliocostalis lumborum) than concentric contractions.
• Maximal strength and endurance of trunk extensors were not compromised by eccentric exercise.
• Increased muscle soreness was observed post-eccentric exercise, alongside significant reductions in triglycerides (TG), total cholesterol (TC), and LDL-cholesterol (LDL-C).
• Blood glucose and HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) increased post-eccentric exercise.

Conclusions:

• Eccentric trunk extensor contractions positively influence lipid profiles.
• Eccentric exercise of the trunk extensors demonstrates beneficial effects on glycemic response.
• Despite increased soreness, eccentric trunk exercises maintain muscle function and offer metabolic benefits.