Exercise Energy Expenditure

Energy expenditure during exercise (Physical Activity Expenditure) is important to know if one wants to prevent gaining fat or is in the process of losing fat. To prevent gaining fat, energy intake must be balanced with energy expenditure.

To calculate exercise energy expenditure on our website we have taken into consideration:

  • Concentric contraction
  • Eccentric contraction
  • Isometric contraction
  • Speed/duration
  • Load
  • Stance
  • Depth/ROM
  • Joints involved
  • Lever length
  • Body size
  • Sex
  • Body composition
  • Weight
  • Resting Metabolic Rate
  • Thermic effect of food

And other variables.

Muscle Contraction

Here are the values we assigned to different types of muscle contractions and the reasoning for the values.

  • Concentric slow 1
  • Concentric moderate 0.9
  • Concentric fast 0.8
  • Eccentric 0.8
  • Isometric 1.6

Concentric muscle contractions at a moderate speed will require work from the antagonists toward the end of ROM for the exercise.

Concentric muscle contractions at a slow speed do not* require work from the antagonists toward the end of ROM for the exercise. Slow speed means more time under tension. More time under tension means more energy expenditure.

Concentric muscle contractions at a fast speed will require more work from the antagonists toward the end of ROM for the exercise. Fast speed means less time under tension.

Isometric muscle contractions are usually maintained throughout the exercise, i.e. through the eccentric and concentric phase of the exercises. One such example is the hip hinge deadlift, the calves are working through an isometric contraction when the weight comes up and down. The amount of contraction required varies depending on how far the weight is away from the body, the same applies for swinging exercises, hence, we assigned a value of 1.6.

*generalisation