Not running, treadmill on cardio with high elevation and at 4.5mph. When I feel like it I manually chnage the settings for 5-10 minutes so the body is not used to it. I read that the body,, being a perfect machine tries to do the work with the least amount of energy wasted so you have to trick it. We can go to McDs now, no need to hunt in Africa for a week hoping to catch something :)
Running for 45 minutes might not be good for your knees (I think)
The body's incredible-- adapts suuuper fast. Among the best things to do to keep it on its toes, much like you're doing (knowingly or not!) is interval training. A helpful guide to how to do that: http://www.greatist.com/fitness/interval-training-complete-g...
Running for 45 minutes might not be good for your knees (I think)