[CoachVick]

CoachVick on September 1, 2010 at 3:00 am #16999

I am interested in hearing the thoughts of some other coaches. I’ve had this discussion with several top track coaches and many performance coaches I respect but still find both their opinions and thought proces vary greatly.

When it comes to using sleds for pure acceleration, how much is too much? Is it 10% of BW or no more than 10% drop-off?

I’m not trying to bait anyone so I will let you know that I regularly use very heavy loads of 50%BW to more than 100% occassionally. There are a lot of caveats that go with this, but the basic point is that there are compelling arguements of why it may be good to add more load. There is very little to refute it other than a “rule” passed down by coaches to athletes. You can read all my thoughts here. ArtofCoachingSpeed

Note, I am talking about pure acceleration. Maybe 1-3 steps for most team sport athletes and no more than 8 steps for most track.

I thoroughly believe many performance coaches mess this up with too much load at times and cross a bound from acceleration work into strength or conditioning. Still, when coaches well, I have found great success using very heavy sled loads as a technical tool, a training tool, and for potentiation.

What do you think and why?

[G-Riv10.57]

G-Riv10.57 on September 1, 2010 at 7:29 am #101589

My understanding was resistance should be approximately 10% of BW…so a 175 pound sprinter would use between 15-20 pounds….However, I have used more resistance in my own personal training 25-45 pounds at 175-180bw w/o a noticeable determine to my training (at least in my eyes)…but never more than 45 pounds. I generally believe that if the resistance causes a visual detriment to sprint form then the load is to high for the athlete. I believe breaking proper acceleration form with high resistance training doesn’t seem to bold well for the proper acceleration phase of the 60/100m sprint and may possibly create mechanical errors in the acceleration mechanics which may then translate into their actual race.

[star61]

star61 on September 1, 2010 at 8:37 am #101591

…Note, I am talking about pure acceleration. Maybe 1-3 steps for most team sport athletes and no more than 8 steps for most track…?

Can you expand on the phrase “pure acceleration”? Sprinters are acclerating through 40-60m, depending on their level, and even team sport athletes are often accelerating for 20-30m.

As far as loads, I have used heavier loads, up to 25%, without seeing any appreciable breakdown in form. In fact, I like to include heavier loads, and steep (30-45 degree) hills, for short accel/explosive start work geared toward football. We also use lighter loads, all the way down to about 5% bodyweight. The heavier the load, the shorter the rep.

I should probably add the caveat that the sled we use has very little friction on grass, where we use it almost exclusively. Even at 25%, the rep is fast and explosive and form does not break down. We have used other sleds that have much higher friction and would never use such high loads on that type of sled.

[CoachVick]

CoachVick on September 2, 2010 at 10:08 am #101624

I adopted Loren Seagrave’s breakdown where the first 10-12m is “pure acceleration” and then the next 20 or so are transition. This is based not on the sprinters actual acceleration but their mechanics. At 20 meters they may still be accelerating some, but they have or are in the process of applying maximum velocity mechanics.

For most team sports I’d say “pure acceleration” is probably 3-5m because they are transitioning into another movement.

[star61]

star61 on September 2, 2010 at 11:45 am #101625

I adopted Loren Seagrave’s breakdown where the first 10-12m is “pure acceleration” and then the next 20 or so are transition. This is based not on the sprinters actual acceleration but their mechanics. At 20 meters they may still be accelerating some, but they have or are in the process of applying maximum velocity mechanics.

For most team sports I’d say “pure acceleration” is probably 3-5m because they are transitioning into another movement.

Understood. That actually corresponds fairly closely to the distances/loads we use…15m with 25%, 20-25m with 15%, 30m with 5-10%.

[CoachVick]

CoachVick on September 2, 2010 at 3:36 pm #101629

Not looking like anyone is going heavy. I think it’s a missed opportunity. To get other thinking, here are a few of my thoughts.

I agree that drastic alterations to sprint technique to pull a heavy load can be very bad for training. Long contact times, different recruitment patterns, accesory muscle substitution, etc… But just because it changes some doesn’t make it bad.

So what, if it acutely changes some kinematics?
Sprinting with resistance changes the kinetics and kinematics. So what? Is that inherently bad? Isn’t that often a goal of training drills?

In coaching athletes I am often trying to change kinematics. That can be the main point. I may be trying to develop a greater arm action, or a larger horizontal force component, or a higher stride frequency. It’s not whether or not heavy sleds change things. For the coach it’s a question of; is it the change you want?

Speaking of different kinematics, what about some other drills that we use? Wall drills change the upper body kinematics, but we decide that the value of training the core and lower body motion is worth the temporary change in the upper body. Plyometrics have different kinematics as do many “technical” drills. Why are those OK but, heavy resisted sprinting is not?

Remember also, of the little data there is on acceleration, this is an acute change while doing the resisted run. The question is what does it do to the actual acceleration mechanics without resistance?

What are you using it for?
This is a key question that should drive our decision to use any drills. I like to classify drills as technical, training, or applied. This helps guide our selection based on athlete and training session goals.

Technical drills are designed to improve motor control, build kinesthetic awareness and teach the athlete how to move. Training drills are designed to elicit a training effect such as force characteristics, or energy system development. Applied drills are intended to add variability and let the athlete discover the movement solutions to different problems.

In a movement training session we will have some of each, but with a focus on one area more than others. I think resisted sprint drills can be used in different ways.

An athlete may get a technical benefit out of heavy sled resistance if it brings about kinesthetic awareness, helps them understand the feel of driving back. In working on 40 yd dash starts, I’ll use that heavy sled to build awareness of what it feels like to have tension in the start position.

It also can be a training drill. We can use it to build special strength and work on the impulse components. When used in a contrast method (which for me is almost always) it has a potentiating effect on the following un-resisted accelerations.

[B Hobbs]

B Hobbs on September 2, 2010 at 4:09 pm #101630

I agree with almost everything your saying here Vick. I for one don’t do anything over 10 ground contracts with a sled (horizontal jumps coach) and only use it to simulate the drive phase. Heel recovery and Displacement are critical to proper acceleration and at too great a resistance you will be losing both. In-turn you will be in positions/angles you will not hit in a true sprint. If sprint positions aren’t important then why sprint at all when you can get greater loads and activate the same muscles through squating and deadlifting?

If you feel that 50% increase in resistance is appropriate, than what about a 50% decrease in resistance (overspeed)? Same percentage but on the opposite side of the spectrum. That is pretty much how I look at things. I like to stay even on both sides for the fence and would never play in one area without being comfortable with my returns if equal and opposite. Just like to hear your thoughts on that.

Interesting read though.

[CoachVick]

CoachVick on September 3, 2010 at 1:52 pm #101660

Great questions. Why not just lift heavy? More often I think that is the better answer too many shy from. There is a different piece however that is more technical and based on motor control aspects. Thats where I really see the benefit. You are right that actual sprint positions and progression of position matters and why I always use heavy sleds in contrast with un-resisted accels.

Would I balance out both more extreme loading and unloading? No, but maybe. The reason why is primarily because I would only use the very heavy loads for those first few steps of acceleration. Since total impulse and force vectors are the bigger issue compared to contact time, I wouldn’t be as concerned about overspeed. I would however, make sure to have a 1:2-4 ratio of resisted to unresisted.

I elaborated a little more over on Carl’s post as well.

[CoachVick]

CoachVick on September 25, 2010 at 3:28 am #102234

If anyone wants to see some heavier sled accels and ground contact time, I put up some videos at ArtOfCoachingSpeed on facebook.

Weigh in if you have any thoughts.