The table below is sourced from:  

The International Association of Yoga Therapists, "Health Benefits of Yoga" by Trisha Lamb

 

Yoga Compared to Conventional Exercise:

Yoga

Other Conventional Exercise

Parasympathetic nervous system dominates

Subcortical regions of brain dominate

Slow dynamic and static movements

Normalization of muscle tone

Low risk of injuring muscles and ligaments

Low caloric consumption

Effort is minimized, relaxed

Energizing (breathing is natural or controlled)

Balanced activity of opposing muscle groups

Noncompetitive, process-oriented

Awareness is internal
(focus is on breath and the inifinite)

Limitless possibilities for growth in self-awareness

Sympathetic nervous system dominates 

Cortical regions of brain dominate 

Rapid forceful movements 

Increased muscle tension 

Higher risk of injury

Moderate to high caloric consumption

Effort is maximized

Fatiguing (breathing is taxed)

Imbalanced activity of opposing muscle groups

Competitive, goal-oriented

Awareness is external(focus is on reaching the toes, reaching the finish line, etc.)

Boredom factor

 

 Some of this is generalisation, of course!  Not all other exercise activities will, for example, have "imbalanced activity of opposing muscle groups", or be "competitive, goal-oriented", nor will all yoga classes offer "slow dynamic and static movements".

Please read with this in mind.  The qualities shown are what will generally be experienced with these types of exercises.