Resisted Sprint Training

One of my favorite sprint training methods that can make you run faster is resisted sprint training using a running sled or the Exer-Genie.

While normal sprint training can be highly effective, most athletes will eventually reach the point where normal acceleration and speed training is no longer making them faster. While modifying the program with the addition of weight room exercises can be useful, listing is relatively general in nature, and as such can only be relied on for changing general strength and power qualities.

Since the most reliable way to improve at sport is to train in a way which is specific to the sporting demands, we must look at other ways to modify sprint training in order to improve the qualities needed to perform better. For improving sprinting performance, athletes should used resisted sprint training, plyometrics, and sprint drills in their speed training program.

Why Do Resisted Sprint Training

Acceleration capability is a limiting factor in sprint performance. By improving acceleration throughout the entire phase of acceleration, athletes can attain higher top speeds and ultimately run faster 60m, 100m, 200m, and 40 yard dash times.

Resisted Sprint Training Improves Effectiveness of Force Application

Athletes who orient forces effectively during acceleration are accelerate better than athletes who simply produce large amounts of force (https://www.ncbi.nlm.nih.gov/pubmed/21364480). The greater the ability to apply force horizontally, and the further into the sprint that force can be oriented horizontally, the further the athlete will be able to accelerate. If an athlete can accelerate for 60 meters instead of 40 meters, they will likely attain a higher top speed and be able to maintain that top speed for a larger proportion of the race.

Morin et. al. 2016 found that very heavy resisted sprints, upwards of 80% bodyweight, was effective in improving 5m and 20m sprint times for soccer players, as well as improving their mechanical effectiveness and magnitude of horizontal force production (https://www.ncbi.nlm.nih.gov/pubmed/27834560). This means that, when using heavily resisted sprint training, athletes were able to orient forces more horizontally, produce higher levels of force in a horizontal direction, and ultimately improve their short distance acceleration times.

Resisted Sprint Training Can Train Determinants of 100m Dash Performance

In looking at the biomechanical determinants of 100m dash performance, Morin et. al. found that 100m performance is associated with (https://www.ncbi.nlm.nih.gov/pubmed/22422028):

• a ‘‘velocity-oriented’’ force–velocity profile
• a higher ability to apply the resultant GRF vector with a forward orientation over the acceleration
• a higher step frequency caused by a shorter contact time

When  we consider what can be accomplished with resisted sprint training, it is clear that we can work on all of these aforementioned qualities using resisted sprint training.

• You can add load to the athlete while not sacrificing limb velocity, as the athlete is only loaded during ground contact. This helps maintain a velocity oriented force-velocity profile during flight while utilizing resistance during stance.
• Resisted sprinting allows for a more forward/horizontally oriented body posture and ground strike, allowing the athlete to work on applying force to the ground in a horizontal or forward oriented vector.
• Because of the altered flight & ground contact times when sprinting against resistance, the athlete can work on increasing their step frequency early, something that cannot be easily practiced without resistance.

Resisted Sprint Training Allows Us To Train Glutes With Specificity

Resisted sprint training allows for the athlete to overload ground contact in a horizontal direction, increasing the demands on the glutei for forward propulsion with an emphasis on the first half of the stance phase.

Once on the ground, the Vastus Lateralis and Glutei do most of the work. Specifically, the Vastus Lateralis works against gravity to support the athlete vertically, while the Glutei propel the athlete horizontally across the ground. Working together, these two muscle groups create the blended vertical-horizontal force vector which produces over-ground sprinting.

During the first half of the stance phase, activation ranks from most to least in the Vastus Laterals, Glutei, and the Biceps Femoris. As each step progresses throughout early acceleration (first 10 steps), demands on the VL decrease, increase on the BF, and stay relatively similar in the Glutei (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689850/#B58).

Considering this, a sprint athlete with the proper load can use resisted sprint training, resisted bounds, or resisted sprint drills to work on rapidly producing force in a horizontal direction in the first half of the stance phase. By punching the ground with a rapid backward and downward strike and while doing so in a resisted condition, the athlete can work on increasing their capabilities of force production and application during the first half of the stance phase - when most of the propulsive forces for the sprint stride are produced.

 

Resisted Sprint Training - Horizontal Vs Vertical Loading

Researchers, coaches, and talking heads alike go back and forth on whether vertical or horizontal force is more important. In reality, the ability to produce both vertical force and horizontal forces in an effective manner while sprinting are important.

The simplest way to think about this topic is that:

• Vertical force production helps overcome gravity and prevents us from collapsing at ground contact
• Horizontal force production is what sends us horizontally down the track
• Force is applied to the ground in a vector which is a blend of both horizontal and vertical force.

Debate tends to center around which is more important. Proponents of the idea that vertical force is most important will state that vertical forces are far higher in sprinting, and thus more important. Furthermore, they may state that since vertical force production is correlated with maximal velocity sprinting speeds, it must be most important.

A more compelling argument exists for the idea that the ability to apply force in a horizontal manner is a determinant of sprinting performance. 

While vertical forces are high in sprinting, the difference in horizontal force production between faster and slower runners is significant, and this difference becomes more pronounced as velocities increase. That is to say, faster sprinters apply force in a more horizontal direction than slower sprinters, and they produce relatively more horizontal oriented forces than slower sprinters at higher velocities.

“As subjects’ level of 100-m increased, this was particularly characterized at high running speeds by the increasing ability to orient the resultant GRF generated by the lower limbs with a forward incline, i.e. to produce higher amounts of horizontal net force at each step, and not by increasing the amount of resultant force produced. (https://www.ncbi.nlm.nih.gov/pubmed/22422028)”

Since horizontal force is progressively more challenging to produce as velocity increases, it would follow logically that the ability to produce horizontally oriented forces at high velocities is a limiting factor in high velocity sprinting performance. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689850/).

With all this in mind, resisted sprint training should primarily be performed with horizontally oriented resistance. This can be performed using a sled, an Exer-Genie, or the 1080 Sprint. Personally, I rely on the Exer-Genie for most of my resisted sprint training work.

Resisted Sprint Training - Practical Application

While theory is important, practical application of any training method is ultimately most important. In the case of resisted sprint training, there are a few things worth keeping in mind:

• Higher resistance has been shown to improve the quality of horizontal force application more than lower resistance.
• Rate of force development and peak force production increase with increasing sled load.
• Higher loads are likely to be more effective for improving early acceleration.
• Moderate loads are likely to be more effective for improving later acceleration and potentially maximal speed.

Personally, I incorporate horizontal resistance in the following categories, using the Sprint Start Sled or an Exer-Genie:

• Resisted sprints ranging from 10m to 50m in length to emphasize the ability to apply force horizontally.
• Resisted bounds at varying loads and distances to emphasize horizontal force production.
• Resisted drills of various types to emphasize specific strength capabilities relevant to the first half of the stance phase.

While the workout itself can vary, one should look first at what they need most and build their program from there. Consider the following factors when planning your resisted sprint training workouts:

• Are you relatively better or worse at accelerating, hitting a high maximal velocity, or maintaining your speed?
• Do you have a large enough work capacity to perform relatively high volumes of high quality acceleration, speed, and speed endurance work?
• Are you relatively stronger or weaker compared to your performance goals?

For those who are better at accelerating, the use of longer sprints with moderate resistance as well as upright bounding exercises with moderate resistance might be best, since you can work on horizontal force production in an upright position at relatively high velocities.

For those who are better at maximal velocity but lack accelerative capabilities, very heavy resisted sprints performed over 10 to 30 meters will be useful in improving your ability to accelerate effectively.

For those who lack speed endurance, repeated resisted sprints of longer distances (30 to 50 meters) can help increase work capacity and sprint specific conditioning, making it easier to eventually transition into true speed endurance work.

If you are relatively strong, it will be more beneficial to utilize higher loads at any given distance. For weaker athletes, lower loads can be used with positive effects. Over time, the goal should be to sprint faster with the same load, or to sprint equally as fast at higher loads. Furthermore, athletes should aim to increase the distances sprinted and the loads used, both in the moderate and long term.

Throughout the year, emphasis can transition from shorter sprints at high resistance levels to longer sprints at lower resistance levels. Athletes can also move from workouts predominantly consisting of resisted sprints, to a more blended workout distribution and ultimately a wholly non-resisted workload.

Resisted Sprint Training Workout Examples

For Short Distance Acceleration

• 6x20m with as much load as you can sprint with, using technique breakdown and rhythm as a guideline for loading.
• 4x2x20m, alternating between 2 loaded sprints and 2 unloaded sprints, also known as contrasting.

For Longer Distance Sprinting

• 4x30m, 3x50m moving from more resistance to less resistance throughout the workout
• 4x2x40m alternating each rep between resisted and non-resisted sprints.

For All Qualities Of Sprinting

• 4x30m at a high load
• 2x40m at a moderate load
• 2x40m with no load
• 2x40m bounds at a moderate load
• 2x40m bounds with no load

For Specific Strength Development

• 2-4x20m A Skip
• 2-4x20m A Switch
• 2-4x20m B Skip
• 2-4x20-40m Alternate Leg Bounds
• 2-4x20-40m Skips For Distance

There are a variety of ways that you can utilize resisted sprint training, and your specific use should be dictated by your needs, the period of the year that you are in, and your current point in your long term training progression.

Sled Vs. Exer-Genie

I use both a traditional sprinting sled and the Exer-Genie and find each has their own unique qualities. Some reasons I like the Exer-Genie include:

• It is far easier to carry around, set up, and pack up than a sled.
• It allows for much more precise loading.
• It allows for much more consistent loading, whereas a sled will speed up and slow down due to momentum changes.
• It allows for a wider range of exercises to be performed safely, such as resisted drills and bounds.
• It allows for use on any surface, and will not damage your track or turf.

In contrast, I like to use my Sprint Start Sled as well for the following reasons:

• I can select loads more precisely with a sled.
• The Sprint Start Sled allows me to perform resisted sprints from blocks, improving rate of force development for my starts.
• Sleds are typically very durable and easy to use.
• In hot environments, the Exer-Genie heats up and can be hard to adjust when hot.

Conclusion

For athletes who want to accelerate more effectively, improve their maximal sprinting speed, or train sprint specific strength related to the stance phase of sprinting, then resisted sprint training is something that should be tried.

Utilize resisted sprint training throughout the year in a way which is relevant to your needs and goals, as well as your current levels of strength and sprinting capability. 

By using short distances and heavy loads, moderate distances and moderate loads, resisted bounds, resisted drills, and contrasts with unresisted sprints and exercises, athletes of all types can add another set of tools to their toolbox in the pursuit of sprinting faster and improving athletic performance.