Strain to the body can be both good and bad. Like all things in life it’s a balancing act. Everyone has heard of a strain/sprain, or over-straining yourself. Usually strain is thought of as bad however strain can also be good. But how do we know when strain is good vs bad? To understand good vs bad strain, we need to understand how strain occurs. Strain to the body is caused in three ways: load, speed, duration.