Comments from the
Commentaries on Physical Activity and Health
How Much Physical Activity is Good Enough?
by I-Min Lee, MD, ScD
In August, Dr. Ken Powell wrote a compelling article on why physical activity should be regarded as a great bargain – a “best buy” – for public health1. Yet we Americans largely aren’t buying. One of the reasons he gives is that there is a mistaken notion that this best buy requires a large commitment on our part: a significant investment with regard to time spent and physical effort (intensity) required. How did this belief come about? And, indeed, how much physical activity is good enough to qualify as a best buy?