Sled vs Hill, which one would you choose?

I know that both can be useful tools in speed training, but if you had a choice with only one, which one would you choose? I’ve heard a good number of people choosing sleds over hills if they had access to equipment because the sled doesn’t change the sprint mechanics as much as hills.

One isn’t necessarily better than another imo…

Sled pro - can adjust load, easier to find smooth surfaces,
Sled con - you have to lower your body to the ground to get into driving angle, equipment and space requirements, attaching belt on your waist, having more resistance at the beginning of the sprint because coefficient of friction is higher at static than kinetic. Roughness of surface will be another variable adding to resistance, in addition to weight itself (slippery surface vs. rough surface, even at same weight, rough surface will provide more resistance)
Hill pro - you don’t have to try to lower yourself into driving angle, because the ground is at an angle, no equipment needed, nothing attached on your waist.
Hill con - hard to find right hill gradient with smooth surfaces (ouch if you roll your ankle…), cannot adjust load.

It really depends on so many of these things and all…My advise is if you have access to a nice smooth hill that is right gradient for you, use it. If you don’t probably use sleds.

I get achilles tendinopathy from sleds but not from hills, so for me the choice is obvious.

Use both but I would lean towards the hill if you have a nice grass hill. It’s easier for me to use sleds when performing contrast work.

There’s a Track and Field Coaches Group on Linkedin where one of the coaches posted some research that appears to show that hills are significantly more beneficial than sleds. But–at least for me–I think the new thing for next season training is sleds with very light weight, which seems to work better for trained sprinters to build maxV, while heavy hills sleds seem to be useful for short distance acceleration training:

See Item #4 below:

Heavy sleds/hills for 0-10m
Light sleds for 20-40m

One size does NOT fit all.

As kwave brought out, and CF mentions in GPP vid, you don’t have to worry about changing your body angle when you are changing the angle of the surface. This is one of the reasons I think hills should be a first option. I thought I also remember seeing CF mention that hills should be the first choice if you can find a smooth one with a proper gradient. For me, I have really felt the difference. The hill has really helped me get a feel for getting my hips up. Mechanically, I see it as superior. I think CF may have mentioned isorobic as a close second, and the sled being after that. But it seems that the isorobic and sled are certainly more convenient than finding a good hill. But to me, there’s just no replacement for how the hills set you up for proper hip height. And when you do exude biomechanical errors, I would say that, from my own personal experience, you certainly feel it more on a hill than with the sled (especially in regards to issues with overstriding). The changes in mechanics that the hill seems to make have been quite beneficial for the kids I’ve worked with.

Remember, the Jamaicans do use a lot of hills. Though, I can’t say I know much on what their usage of sleds is like.
And in CF’s sample plans, I have seen hills, but not sleds. So for these reasons, hills are always my number one preference.

I use hills as well, but some people don’t have a stable hill with the proper gradient available. For some of those, stadium steps might also be an answer as well as sleds. Other things should also be factored in, including box jumps, drop jumps (up to 30"), and depth jumps at times. This is one of Verkhoshansky’s main papers, showing (p.20) that you don’t really need that much of a depth (~30cm) to get a significant stimulus (It doesn’t have to be really high risk).

Thanks for the links. Basically hills are better for acceleration training and a light sled would be better for power output in max velocity?

I’ve read on some running forums where posters who don’t like hills too much reason that running up a hill significantly increases ground contact time and slows your stride, which in turn teaches your CNS to “run slow”? I don’t know how much science and research this is to back that up or is it just “bro science”? lol

Overcoming inertia necessarily involves longer, initial, contact times; no matter whether on a hill or the flat. Adaptation necessitates stimuli and the appropriate grade hill, as one example, is such a stimulus whose adaptive response is faster acceleration on the flat in large part due to the specific strength and acceleration mechanics that are developed on the hill by way of competent coaching.

If that were valid there would be little justification for doing any low intensity/supplemental training. Using hills for developing extension, strength etc is valid whatever the CNS demands.
Given the recommendations of cf and numerous other renowned coaches about the benefits of hills i am inclined to take their advice.

In addition, whatever forum people jquick is referring to must not understand physics because any static body endeavoring to overcome its inertia is faced with lower initial velocities relative to what is achievable given sufficient distance and force application. Meaning, ground contact time is longer during initial acceleration regardless if one is sprinting on a hill, against a sled/isorobic, or unresisted on the flat.

Clearly a hill too steep ceases to be a direct velocity stimulus, however, strength developed on that hill may, given the right sprinters, positively transfer to improved acceleration on the flat for supportive reasons.