I remember in the 90s, everyone used to try to train at their burning fat target range.
It was like if you are not at a certain level, the workout wasn't considered suitable.
And that is far from the truth.
Any movement is suitable to a certain level.
The opposite is true. If you are overdoing it, then it is not good.
There is a point in training where pleasure is together with exercise and in my opinion that's the right target.
When pleasure becomes torture, then you are in the wrong town.
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That's an old way of measuring performance.