We know that adding resistance to movements makes you stronger and faster.
Adding resistance to some movements is obvious. To jump higher, for instance, you can squat with weight. To push harder, you can do presses or explosive push ups.
But how do you add resistance to activities where you’re moving through space instead of sitting on a bench? For instance, how do you add weight to sprinting?
Well, cement shoes or running piggyback are two possible options. Another one is dragging a sled.
The idea of pulling a sled isn’t completely out of the blue. One of the all-time great movie training montages, from Rocky IV, features Rocky pulling a sled through the snow.
If you want to run faster to improve your performance in a given sport, or a change of pace from your regular workout routine, you can try pulling a sled.
Now, sled pulling isn’t fancy or complicated. Load a bunch of stuff on a sled and run. (Or try.)
However, if you want to improve your sprint speed specifically, then there’s a little more to it.
Goldilocks and the Three Sleds
Just like the children’s bedtime story Goldilocks and the Three Bears, there is a “just right” to how much weight you should pull.
Too little weight and the sled slides past you when you stop running – meaning you’re not getting much of a training effect. Another sign you don’t have enough weight on the sled is that it becomes airborne during your sprint. And considering it’s moving towards you, that’s probably not such a great idea.
Too much weight and you’re nearly parallel to the ground when you “run”. Shockingly this running pattern doesn’t translate into a “normal” load free running pattern.
Thus, with too light a load there isn’t enough of a stimulus. With too heavy a load your running pattern becomes sub-optimal.
But if the load is “just right” then you have a training overload and proper running pattern — I’m calling this the Goldilocks phenomenon.
The 90% rule
So how do you figure out what’s the “just right” weight to use?
It turns out that three separate studies have already figured out what the optimal loaded sprint speed is. Since there are three separate studies coming up with the same conclusion I’m pretty confident in their findings.(1-3)
They agreed that with the loaded sled, you want to slow down by 10% of your normal sprint speed.
Thus, if you can run 30 metres in, say, 10 seconds then the optimal loaded sprint speed for you is 30 metres in 11 seconds. (10% of 10 = 1, thus 10 + 1 is your ideal time.)
If you can run 30 metres in 50 seconds, then your loaded sprint speed is 55 seconds. And you obviously really need that sprint training.
In other words, if you keep the distance the same between loaded and unloaded sprints, you should take 10% longer to finish your sled sprint — no more and no less.
OK, that’s the speed. But how do you figure out your “optimal load”? Well there are two ways:
- Trial and error: simply try different loads until you hit the magical 90% speed.
- Use an equation that somebody already figured out.
Luckily this week’s review is on a study that figured out an equation for optimal load when sprint training with a sled.
Read the rest here.
Most Popular