One of the best guidelines to measure overall positive benefit of an activity: Does it increase your range in one (or more) important factors of physical life. For example, increasing your ability to generate tension is good, but even better increase your ability to create both tension and relaxation in the same workout. Or perhaps your ability to manage both high levels of nervous system activity/activation (stress, fear, movement, complex/dynamic physical environment) and deep calm. Or range of motion (flexion/extension). Or balanced range of spatial awareness.

Bonus points for combining multiple ranges in one activity. Double bonus points for expanding a range in both directions simultaneously...

"You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete."--Buckminster Fuller