Power output of the lower limb during variable inertial loading: a comparison between methods using single and...

Area of Science:

• Biomechanics
• Exercise Physiology
• Sports Science

Background:

• Understanding the relationship between power output and inertial load is crucial for optimizing athletic performance and training.
• Previous research has explored this relationship in various movements, but a direct comparison between single-leg thrusts and cycling is less common.

Purpose of the Study:

• To investigate the power-inertial load relationship of lower limb muscles during single-leg thrusts and cycling exercise.
• To compare peak power output and mean power generation between these two distinct exercise modalities.

Main Methods:

• Nine young male subjects performed single leg thrusts using the Modified Nottingham Power Rig (mNPR) and cycling exercise.
• Various inertial loads were applied to assess their effect on peak and mean power output.
• Statistical analysis was used to determine significant differences and associations between variables.

Main Results:

• A parabolic-like relationship between peak power and inertial load was observed during mNPR exertions, with peak power occurring at a specific inertial load (0.158 kg m²).
• Cycling exercise showed significantly less power output only at the lowest inertia, with power remaining relatively consistent across other loads.
• Maximum peak power output during cycling (1,620 W) was significantly higher than during mNPR (937 W), though mean power generation showed a strong positive correlation (r=0.84) between the two methods.

Conclusions:

• Optimal peak power expression during single contractions (like leg thrusts) requires a specific range of inertial loads.
• Cycling movements, characterized by repeated accelerations, are less dependent on a narrow range of inertial loads for maximal power output.
• The findings highlight the distinct biomechanical demands of single-effort versus cyclical movements concerning power-inertial load dynamics.