The debate and controversy on the best way to use weighted sleds for getting faster is timeless. When your sole job is getting someone to run faster, no excuses exist when they don’t. After years of seeing some of the best programs firsthand and talking to great coaches, I’ve concluded that weighted sleds should be a speed tool, not a labor of strength. In this article, I will demonstrate why lighter sleds are better options than heavy ones, and why timing sprints with sleds is wiser than chasing plate loading.
Nailing the Coffin Shut with Heavy Sled Research
Some research shows the value of various weighted sleds when sled training is the primary option, but what about stepping back and seeing the big picture? Early acceleration is about overcoming inertia, and that means maximal strength and power transfers to getting a body in motion quickly. When the body speed increases past the 10m or so, then we see the ability to accelerate to maximal speed (terminal acceleration) showcased with lighter sleds improving late acceleration. Early acceleration in research has some relationship to exercises that involve maximum strength and power qualities, so when choosing a sled load most will pick something close to 10% of one’s bodyweight. I have mentioned the problem with percentages in the past, and here are four reasons why this is a poor approach to using sleds.
Bodyweight is Vague. One athlete who is out of shape and explosive and another who is lean and very powerful may share the same mass, but it’s not a good number for base-loading a sled. Even two athletes of similar build (height and lean mass) may have different speed abilities.
Speed is Variable. Sprint velocities in training will change over time and vary from fatigue, so loading must be adjusted constantly. Some smart coaches have used a percentage of dropoff in velocity by timing sprints with and without loading.
Acceleration Curves are Individual. Some athletes are more talented or gifted in different areas and can benefit from having loads catered to improving areas in acceleration they may not be doing well in. While everyone has to worry about the first step regardless of the sport, it’s a good idea to be good in all areas of speed to reduce injuries and improve the efficiency of running.
Athlete Program Variance. Each system of training will use modalities and sequences differently. My own program on the track—integrated with a successful weight training program—may fail. Some coaches are known to collect a “greatest hits” of training systems and combine them into one program. Sometimes this works, sometimes not. Sled training must reflect the entire training program and not be seen as an isolated variable. On the other hand, just because a program is well- rounded doesn’t mean the specific task of sprinting with sleds should be tossed in without careful attention.
The best approach is clear, but requires some experimentation. I never timed sprints much before 2000, since I was always a proponent in the 10% of bodyweight rule until I realized it was a very rough guideline. After looking at athlete training in the weight room and jump testing, along with speed timing without the sled, prescriptions must be carefully tailored or you are missing the opportunity for better results. If you are looking for results, see how loading the sled improves the rate or acquisition of better performances in speed within your program, not in isolation. After seeing the cause and effect carefully, use that approach and reap the benefits. I have no emotional attachment because results are about faster times, not smarter coaches. We often overthink things and let’s be direct, our top priority is getting athletes to go faster.
About the Top Workouts
I can’t claim to have invented or designed any of these workouts. Much of the input comes from the classic USATF education process and talking to college and club coaches. For me the opportunity to train is about specificity and balancing general qualities with a recipe that is consistently working year to year. Each workout has a unique theme or small benefit, but the overtone is getting loaded speed training, not slow motion running. Obviously many specific details exist in making the workouts fit each program, but with so many universal qualities of training consistent with programs, weighted sled workouts will be easy to integrate without much adjustment.
The combination of hills or ramps with sleds is interesting. The reason is very simple. Hills or ramps can train more people, so if you have a great hill all the better, but take note. Natural inclines with hills (opposed to man-made ramps) are a crapshoot at best in getting one that is constant and safe. Using the sequence of hills to sleds to free sprints gets three unique qualities trained. In addition, hills are great for teaching. It’s nearly impossible to overstride with hills and sled sprinting, so one of the most underrated parts of sleds is the teaching component.
Hill Sprints 4-6 x 15m
Sprinting uphill should be about conditioning knee lift and full arm stroke. Limb frequency will be artificially higher because aggressive inclines don’t allow for much horizontal or total velocity (total displacement) so athletes feel fast but are not displacing themselves as fast as they feel. Since athletes are not risking falling over as the hill provides the lean, acceleration is rather constant and flattens out early. You can walk into the hill or start immediately running, all based on what your location gives you. In some flat areas, finding a hill is like searching for the fountain of youth, so not everyone will have one.
Sled Sprints 4-6 x 15m
As soon as the athlete starts sprinting after the hill, we like what we see on the clock and on film with total body technique. I have found that when athletes have resistance they have time to change arm action and become comfortable with more patience. I like to use a load that keeps speed near the 10% dropoff suggested by experts, but when one is using sleds in the fall the times captured are already slower than best times, so I add weight slowly based on timing.
Free Sprints 4-6 x 15m
The body is tired after sprinting 8-12 times, and the hope is that the teaching qualities and the state of slight fatigue will create a way to calm the athletes and have them go to technique even more. Much of speed training is not about biomechanics or physiology, but rather mental focus. Athletes too pumped up are choppy and stiff, and slight fatigue will sometimes yield good sprinting times because the athletes are forced to do it right rather than do it hard.
Doing nearly 300 meters of speed work may seem like a lot but the reality is that fatigue is not as great because it’s acceleration work, an area many athletes can build capacity for. It’s a great medley to perform when athletes have limited equipment. You can reverse or stagger the sequence for dealing with limited equipment or coaches as getting the work in matters more in the long run. But if you keep this sequence you will see some nice improvements in technique.
Thunder and Lightning
A lot of coaches ask about contrast work with sleds and the benefits that can be actually measured. Measuring benefits is a great start, since the simple question that must be asked is what’s it worth? It’s hard to see how loading sleds shows up acutely with potentiation or neuromuscular overflow without measuring speed, so I timed sprints to see. The theoretical concept is that using a sled to overload sprinting will result in faster unweighted runs down the road. The problem that is no coaches will ever hedge their bets in one modality, so the idea that weighted sleds will in turn improve unloaded sprints acutely is farfetched. I have done various contrast work and seen mixed results, with mixed reasons to complicate things more. Everyone wants things to be simple, but just doing simple things is not an easy exercise.
Video 1. The best body motion system available is the Myomotion system from Noraxon. No better solution exists for teams or colleges looking to solve real-world challenges. The software is elegant and clean, and the information is game- changing. Here is a video clip of weighted sled sprints and how hamstring recruitment can change based on small factors.
After 2-4 timed sprints, add a weighted sled for 1-3 repetitions and see if the next few unweighted sprints are fast. Trust me—you may see some great things with young athletes by just learning to sprint better and finally having training time between competing, or you may find the athletes are tired. I have seen it all and feel contrast work is good in theory but not that valuable with most situations. Besides managing fatigue by unloading, what is the true physiological benefit? Potentiation works, so why don’t weighted sleds just work like a charm?
Potentiation tends to show up in studies with very small volumes that don’t represent most training programs, so take any study with a grain of salt and do your own measuring. Too many coaches wait for research when good measurement tools and recordkeeping can share the results. Sprints are very sensitive and it will take a few reps to warm up. If the sled repetition works with just one run, what is the expected improvement? Even a 1% change, taking a 4.05 30m sprint to 4 seconds flat is amazing for weeks of training. Potentiation works well with lifts and jumps, but nothing I see in the research shows anything with sprint running. So why do it?
The truth of the matter is that contrast works well by adding variety and possibly getting an athlete into a comfort zone with certain time signatures when running. I like the concept from a mental management perspective because athletes love the feeling of being unleashed and the final performance, not just sport science. While athletes are similar to race cars, they are also the drivers, not just the vehicles. Getting athletes motivated and thirsty for sprinting is an art.
My workouts using sleds typically involve finishing with unweighted sprinting. We perform 8 sprints of 15-20m with sleds followed by 4-6 sprints of 20-35m. I like either doing 3-4 longer sprints of 30-40m or 6 short sprints and see how the splits show if there are any changes. Remember that just a one-kilogram change on the sled will show up on the clock so load incrementally if you need to. I like combining deep squat jumps with longer accelerations and more Olympic lifting options with shorter sprints. Some may argue that the compatibility of training units is not granular, but if you are really trying to get faster in the sprint world, each hundredth is a battle.
Intermediate athletes can take the next step beyond steady loads and focus on mixed loading. One area I find difficult is what to do with adjusting loads during training, as weights and weighted sleds are not the same. Weight training fatigues faster per rep, but sprinting doesn’t have the same process. In sled loading, you should only add weight when improvements in speed are showing, or remove weight when athletes are tired. Any exposure time to sprinting, even with track athletes, is only a few times a week and you need to ingrain rapid contractions. Velocities that drop by 20% or resemble marching and tug-of-war routines are not speed options. When sleds become strength tools they are not speed training, but strength or weight training options.
Mixed loading is about the resistance of the sled as well as the rest interval and length. Sleds are not just creating neuromuscular changes. Some interesting things also happen when rest intervals are reduced slightly with sled sprints. Sled work fatigues athletes at local areas, specifically at the knee extensors, and can create lactate responses of over 20 mmol. Even fit athletes with amazing aerobic capacity—and lower Type IIX fiber profiles, I might add—will create deep responses. I have been looking into myoglobin and mitochondria changes for a few months and don’t have a confirmation of what is going on. But sled sprinting does have an effect on repeat sprinting, even when adjusted for general power qualities from the weight room.
Suggestions for workouts are simple: the shorter the sprint, the heavier the load—but limit it so that athletes don’t lengthen ground contact time to the point they are risking near-double-leg support mechanics. Pusher sleds, such as the Prowler, have value with exposing athletes in team sports to some unholy levels of lactate and building toughness. But when athletes have a double support, they leave the sprinting world and enter the walking zone. Some coaches claim they can eyeball speed and know when the load is too heavy, but I prefer timing and looking for times in the running stage.
Complementing the acceleration loading is ensuring that distance and postures are in harmony, meaning it may work better to have athletes use the proper starting technique with each sprint. Sleds and harness runs tend to keep the athlete in the same leaning angle while speed increases, so it may make sense to rotate postures to remove a fixed motor pattern. I have no data to support this, but I have seen some of my athletes do well with a finite number of workouts. When we changed, they regressed with timing.
Options in pattern loading are arbitrary and have no researched benefit beyond managing fatigue and motivation, so I like alternating between ascending, descending, and equalized patterns. In layman’s terms, one can add load by group of sprints, decrease per group, or increase and decrease to keep output more constant. Good training is about having a great session, not popping out a good run and thinking that will be the session that transforms training. Conversely, sometimes a workout changes an athlete from a learning perspective. So when a session clicks, repeat the joke until the laughs stop.
One surprise to me was hyper-light sleds and the impact with late acceleration among sprinters in the 10.2-10.4 range. When I was in Orlando two years ago at a training camp, I met up with Hakan Andersson. I was discussing the insane claims of some “strength coaches” about heavy sled training and results in speed. I was shocked when he told me how light was the resistance he used. Even I, a lighter-the-better believer, was still using sleds perhaps too heavy for high-velocity resistance. From the current study on sled sprints and very light loads (5% of bodyweight), researchers found that long acceleration—greater than 30 meters—was effectively improved by very light-resisted sprints with sleds.
New equipment, such as the 1080 Sprint, is starting to become more visible. One question is the value of having a mechanized resistance versus traditional friction in results with sprint training. While I like the idea of having data on the training, the key question is what is the differentiation between a 10-dollar device and something closer to buying a compact car? In my earlier article on overspeed training, I reviewed a customized system used by Swedish and Finnish coaches, but the value of high-priced expensive systems is hard to calculate. In my opinion, an easy concept to look at is the improvement of speed coming from any modality. A water jug, a cord, and a soft belt are likely to provide most of the resistance needs for long acceleration sprints.
I made a few “Jug Tugs” over the last year and find it to be a great tool for training camps, but the durability is not there and should be considered a disposable (recycle) option. What I love about the light resistance is that athletes need variation without changing what works. Sprinting with very light resistance should follow normal guidelines of unloaded sprints, and I prefer using sprints of 50m with a standing start. Five or six hyper-light sled sprints are great ways to help improving the surge from 40-60m and this means more technical and radical changes in power.
The Nitro Special
Sometimes athletes need a special workout as they are stale and hungry for improvement. I have looked at all of the potentiation workouts and found them very difficult to do without getting out of the sled harness. When an athlete is literally tied down, it makes it hard to do much besides walk back, and the loose line makes me uncomfortable with plyometric pairing. When working with very small groups or even individuals, the Nitro Special comes out, and we make sure every sprint counts. I only do the option a few times a year even though it’s not taxing to the body. It’s an administrative burden instead.
The Nitro Special is 3-4 weighted sprints, followed by one unloaded sprint. If athletes are familiar with jumping options, we do a few very light jump squats in the past. One detail I find important is to unload one 2.5 pound (1 kilogram) plate with each rep, for two important reasons.
The first is the commonly known issue with sleds that even if an athlete rolls forward to remove the slack of the line or cord, some jerky responses may happen in the first few steps. Those who rush the force application will see many more jerky sensations while those who go too slow will feel smooth, but the temporal pattern is not valuable.
To combat specific timing issues, I like to load up small plates and remove one each sprint. I like the athlete feeling pressure to increase speed, which is the second rationale for incremental unloading. After the last rep, we take three minutes off, and it’s about internal focus rather than expecting a free lunch from neurological phenomena with regards to potentiation. A few squat jumps or even a mean overhead back throw feeds the monster within the athlete.
Overall the purpose of the Nitro Special is not cool sport science or secret Russian training methods. It’s a way to help provide success to acceleration training by moving from special overload to the actual sprint. To me it’s not going to make an athlete faster by the training, its purpose is to keep athletes focused on the task at hand and execute. Coaches and athletes can repeat the sequence 3-4 times or just do it once in a workout, as no rule exists to implementing it into a program. I like using it during an SPP (special preparation phase) just before competition begins, but I am sure it can work earlier in a training season.
Closing Thoughts on Sled Sprints
Acceleration development with weighted sleds isn’t rocket science, so focus on timing workouts just as much as you would time regular sprints. When adding sleds to a program, let’s not overthink things. Instead, think resisted sprinting, not overloaded running. Choose workouts and training programs that show improvements, and keep things very straightforward. Paying attention to detail transforms a good plan on paper to a brilliant workout. The next time you see ego or foolish loads that resemble “Call of the Wild” sled dogs, make sure the sprints need electronic timing—not sundials.
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