Effects of arm and leg loading on sprint performance

Area of Science:

• Biomechanics
• Human Movement Science
• Sports Science

Background:

• Sprint performance is crucial in many sports.
• Understanding how external loads affect sprint mechanics is vital for training.
• Previous research has explored various factors influencing sprint speed.

Purpose of the Study:

• To investigate the impact of increased limb moment of inertia on sprint kinematics.
• To differentiate the effects of arm loading versus leg loading on sprint velocity.
• To determine whether changes in stride length or stride rate are primarily responsible for velocity reduction.

Main Methods:

• Twenty-four male students participated in the study.
• External loads were applied to increase the moment of inertia of either the arms or legs by up to 50%.
• Sprint times over 0.5-15 m and 15-30 m intervals were measured.

Main Results:

• Increased leg loading led to a progressive decrease in sprint velocity during both measured phases.
• Arm loading resulted in a modest, statistically significant reduction in velocity only during the second sprint phase (15-30 m).
• The primary factor contributing to reduced sprint velocity was a decrease in stride rate, with stride length remaining largely unaffected.

Conclusions:

• Leg loading exerts a greater negative influence on sprint velocity compared to arm loading.
• The reduction in sprint velocity under increased limb loading is mainly attributable to a decreased stride rate.
• These findings have implications for strength and conditioning programs aimed at enhancing sprint performance.