Overview

In biomechanics and sport science, work refers to the transfer of energy that occurs when a force is applied to an object and it moves in the direction of that force. It is a key concept in understanding how energy is used and produced during physical activity. The more force applied and the further the object moves, the more work is done.

Work is calculated using the formula:

Work = Force × Distance (in the direction of the force)

Measured in joules (J), work helps quantify the physical effort required to move objects or body parts during sporting actions.

For example, when a weightlifter performs a clean and jerk, they apply force to lift the barbell vertically over a certain distance. The greater the weight and the higher it's lifted, the more work is done. Similarly, a sprinter pushing off the blocks or a cyclist climbing a hill are performing work to overcome resistance and achieve movement.

Positive work occurs when the force and movement are in the same direction, such as when pushing off the ground during a jump. Negative work occurs when the force acts against the direction of movement, such as during landing or the controlled lowering of a weight. This type of work is typically associated with eccentric muscle contractions, where muscles lengthen while generating force to control motion.

Work is also closely related to power, which is the rate at which work is done. In sport, athletes often aim not only to do work but to do it quickly, making power (work divided by time) a crucial factor in explosive movements like sprinting, throwing, or jumping.

Understanding work helps coaches and athletes design effective training programmes. By increasing the amount of force an athlete can generate (strength) or the distance over which that force is applied (range of motion), total work output can improve. It also provides a scientific basis for measuring effort, planning progressive overload, and monitoring mechanical efficiency during performance.

Work is a measure of the energy required to move an object. Whether lifting, running, jumping, or throwing, work is being done every time an athlete applies force to achieve movement. It’s a fundamental concept that underpins much of human motion and performance in sport.