I find it increasingly difficult to exercise. is it true that the body can become resistant to adrenaline? what is it a hat can be done to reverse it

Variety: The body does not become resistant to "adrenaline" however, thecan get "used to" a workout with the same routine seemingly producing less results. Maybe time to mix it up. Interval training is a great way to energize your workout without requiring significantly more time. Consider walk/jog program for beginner or speed work/ hill repeats for experienced. Spice up routine with a new class.