You might remember when I coached Daryl Gee for the Mr. Olympia. One particularity of his routine was daily "eccentric-less" training. It consisted of various forms of Prowler pushing and sled dragging.
Remember, the eccentric phase of a lift is usually the lowering or negative portion where the muscles lengthen and stretch. Eccentric-less work removes that portion. If you think about pushing against a sled, each step forward against the weight is concentric. There's no negative.
I also used frequent sled work with a 63-year-old bodybuilder who was making a comeback. He wanted to get back into competing, but his knees were messed up. He couldn't do any traditional lower-body exercises – no squats, leg presses, lunges, leg extensions, etc.
He'd come to see me three days a week and we'd do various types of Prowler pushing and sled drags for his lower body. He ended up winning the overall against guys half his age and his legs were his best body part! He was also able to resume regular lower-body training afterward because his knees were fixed.
Two Lessons From This
- Prowler/sled work is effective at increasing size or strength if you use the right parameters.
- This type of exercise can be done very often.
Sled work is pretty much devoid of an eccentric load. As such, the amount of muscle damage created is very low. That means you can recover quickly.
For hypertrophy, since you're not causing much muscle damage, you must rely on other pathways to stimulate growth:
- Fiber fatigue
- Lactate accumulation
- The release of growth factors.
All of these are maximized when the time under load is significant, but not so long that loading has to be light. So 30-45 seconds of work seems to work very well.
If strength is your goal, opt for very heavy sets of 10-50 meters with an ideal distance of 30 meters.
And, obviously, you can do sled work for conditioning. You can go as high as two minutes per set. I prefer to stay in the 50-70 second zone with either a challenging weight or a challenging speed.
When you do frequent (even daily) Prowler/sled work, do one version per day for 3-4 sets. While very little muscle damage is done, you still use a lot of fuel when doing them, so you can end up releasing too much cortisol if you go too heavy on the volume.
Note: The 63-year-old bodybuilder used 2-3 variations per workout, but that's all he did on those workouts. If you add them to your sessions, select one variation per workout.