In the past I’d always thought stamina and endurance meant the same thing. That both meant roughly how long you could exert yourself during, say, a run.
But after many weeks of training and talking to my trainer about it, I now better understand the difference:
Stamina: this is a measure of the maximum amount of time you can exert your muscles at maximum strength or capacity.
Endurance: this is the measure of the maximum amount of time you can exert your muscles, regardless of how much strength you’re using.
For example, if you are a marathon runner, you’ll prioritize endurance in order to be able to keep running for long periods. Stamina, which measures how long you can maintain full speed running, is much less important.