Does a brisk walk count as a workout to have a PW meal?
Unfortunately, the answer is no. Going for a brisk walk is of course better than sitting on the couch and highly encouraged but it doesnt put your body in the same state as a more intense workout would. The above being said, if youre physically limited (fitness, illness, etc) such that walking is your only form of exercise, and youre unable to cut starchy carbs cold-turkey, you can start off by scheduling these foods in the time following your walks. Then as you progress, you can either move up to more intense exercise or youll have to cut down back / remove the starchy carb sources. For those who have good carb tolerance, you very well may be able to eat starchy carbs after a walk but that has much less to do with the walk and more to do with how your body would handle the starches anyway.
