I have been doing 5-3-1 for the past 6-7 months and I love it. Then about 2 months ago I started doing hill sprints and its amazing how brutal they are. Unfortunatly hillsprints will be a no go soon enough with winter sneaking up and that means conditioning will have to take place inside. I usually do alot of interval sprints, jumprope and rowing during the fall/winter months but I would like to continue with hillsprints level of conditioning.
I dont have a prowler or a running sled, unfortunatly, nor do I have an area to run stairs. I was wondering if anyone had any suggestions for winter conditioning comperable to hill sprints.