Isotonic (exercise physiology)

Isotonic exercise is when you make your muscles stronger by moving your body in a way that is the same amount of force as the resistance you are working against. Imagine you are sitting on the floor and your friend is holding a big fluffy pillow in front of you. If you push against the pillow with your hands as hard as you can, you are doing isotonic exercise. This is because the force you are pushing with is the same as the force of the pillow pushing back on you.

Now, if you did the same thing but your friend held a heavy brick instead of a fluffy pillow, it would not be isotonic exercise because the force you are pushing with is not the same as the force of the heavy brick pushing back on you.

Another example of isotonic exercise is doing a bicep curl with a dumbbell. When you curl the weight up, the force you are using to lift the weight is the same as the force of the weight pulling back down on your arm.

Overall, isotonic exercise is a way to make your muscles stronger by working against a force that is the same amount of resistance as the force you are putting out.