Elitetrack: Sport Training & Conditioning

i plan to start stretching again to increase flexibility.  what kind of stretching should i do?  ive heard that PNF is fast, but also has bad effects on power output.  actually i think ive heard that most stretching has a bad effect on power output.  is there a way to get around that?  also what days should i put that kind of stretching into my program?  and add anything else anybody wants to tell me about adding stretching to a training program.

any thoughts?  i currently only use static stretches, and sometimes another that would probably fall under the 'ballistic' category.  but thats really more to warmup my legs than increase flexibility

I'd incorporate dynamic stretching into your routine. The detrimental effects of stretching on power output are not yet fully unerstood, but generally it looks like the longer and deeper you hold a stretcch, the greater the diminishment in power output. Also, the shorter the duration in time between the stretching and the activity the less the effect. I know Phoenix has some interesting viewpoints on this topic…........Carl, have anything to add / say?

Does anyone have any sites I could go to for all the dynamic stretches one could perform? Or does anyone have a dynamic routine that they follow and could show me?

by dynamic do you mean the kind that hurdlers do where you swing your leg off to the side for a groin stretch and back for a hamstring stretch?

I feel that the intensity of PNF work (the method on trial here) is not heavy enough to interfere with performances unless it is acute and heavy. I have seen two elite sprinters (one world recordholder one gold medalist) use such a protocol as part of a warm-up.

some points for debate…

If stretching before speed is bad how long does this effect last?

What intensity?

How long the holds?

What musclegroups?

Will warming up reactivate the motor functions and allow for full power later?

I would use some light PNF work for very tight but very fit athletes as part of the warmup 45 minutes before the first round and maintain tonus with manual therapy. PNF is also a trained method and people will addapt to the stress of the work.

If stretching before speed is bad how long does this effect last?

I have seen in two studies where MVC decrement last up to hour post stretch. However,,,,,,,,,, this segways to other points, I believe studies had some very long holds.  30 seconds x 3 or one may have even been 20 minutes of repetitive stretching of the tricep surae.

Will warming up reactivate the motor functions and allow for full power later?

I guess this is my biggest question as I look through the research. I hope to have an answer sometime in the next several months.

I would also throw two points together, is it warming up that reactivates or is it how time from stretch to speed that reactivation occurs?

What are your thoughts Carl on the points you asked?

Originally posted by cockysprinter
by dynamic do you mean the kind that hurdlers do where you swing your leg off to the side for a groin stretch and back for a hamstring stretch?

I mean that kind and any other kind that is available for sprinters.

well you could just make them up to suit your needs.  you might swing your leg forward and then curl it on the backswing to get a hamstrings/quad stretch.  or swing arms across your chest to get shoulder/chest.  or you swing your arms up and curl the back, then straighten them out and swing back for a bicep/tricep stretch.

arggg you guys are too technical…. phoenix, in your opinion will warming up reactivate the motor functions for full power? or todd, or mike.  todds post seems to suggest that reactivation does occur, but the reason is unclear.

MJ used AIS (a form of PNF) a half hour before his 19.32….could he have gone 19.2 if he used dynamic stretching? I doubt it.

I think MJ is unlike any sprinter EVER born. What MJ does and/or did should not and does not apply to almost any other human. I think he was so far advanced in his training and so sharp and ready to go that nothing could have changed whether he did AIS or dynamic.

MJ is human and…being elite would be more sensitive to his training.

I have an abstract of a study that may be of interest that we did here at LSU with some of our jumpers. I mentioned it a little while back and will try and remember to post it when I get to the office. In the study, jumpers were 0.04s slower (statistically significant)over 20m after they had static stretched. As Todd mentioned though, the static holds were long (30 sec).

I understand many athletes have suceeded with various types of stretching routines but the scientist in me looks at the growing evidence about the (at least acute) detrimental effects of stretching on high power output movements and it makes me very cautious of using too much flexibility training, especially prior to competitive efforts. Also, understanding the mechanical properties of the muscle complex makes it hard for me to concieve how static or traditional PNF could enhance performance when used just prior to performance. Having said that, I do think there are plenty of good uses for various flexibility routines and I use some form of flexibility training everyday. Like I said though, I'm cautious in using it before competitive efforts. However, I do agree with Carl that the method, timing, and intensity of the stretch are probably the most important factors in determining its effects.

Here is my opinion based on observations…I then tried to explain what I see using some raw (read very raw physiology).

stretches with long holds and heavy forces tend to reduce power in research. This tends to be acute and I have failed to see any research showing that a warm-up—> light PNF—> then more warm up——> then wait (30minutes for elite comp) would interfere with power.

I think the window is 20-30 minutes after intense stretching and duration increases the loss of performance.

more thoughts…speed days are a on days when rest has been present. If your training is right you should not need too much range of motion work prior to the workout because every day you are doing something to keep the range of motion even and constant. everyone wants to improve range of motion but that's all you have to do is keep it at full range by doing consistant work.

Mike makes a good point, in that the properties which are altered from a stretch are the same ones that what make power athletes successful.

The duration could be the biggest component.  I believe somewhere in the 6 second range of a stretch is where inhibition is achieved.  This may explain why AIS can be utilized with its shorter holds.