T Nation

adaptation

I agree with CT on the body adapting to a certain type of training in 2 weeks… and certainly in 4 weeks. But does this apply to intervals? eg 400m? or cardio? i mean… isnt is good to adapt to repeated 400m runs? (from a sports standpoint?)

regds
Jonathan

Energy system adaptations take longer to occur than 4 weeks but can still be periodized in the same manner. I think what you’re referring to is the way Christian periodizes the 400 meter sprints over a cycle. This works well because as your fitness state increases over the cycle your fatigue state also does, but when you lower the volume the fitness effect lingers 3x longer than the fatigue effect so your performance will also increase