Once again, the lack of human subjects in my photograph collection shows itself, as I'm compelled again to substitute another animal (or animals, in this case) in lieu of a swimmer*.
The musculature of any elite athlete is impressive, but perhaps none more so than swimmers, because the range of motion they must achieve and the difficulty of moving through water for non-fish-shaped creatures necessitates acquiring both the strength and/or endurance to push through the water, and the flexibility to ensure that every ounce of your strength is not wasted.
So we begin to see the appeal of resistance stretching. As it's usually described, you resist an applied force as you stretch. Rather than just reaching over and touching your toes, you have to reach for your toes while pulling against an elastic band, for instance. This is what Dara Torres credits for her incredible swim times in the 50 and 100 m, after all, and since she's tested clean, we're led to believe that there must be something to it.
But if you clicked on the link, you'll see a lot of mumbo-jumbo about meridians, personalities, fluff about "empowerment", and not a single shred of how it works--or even a proposistion for how it works, if it is indeed the miracle workout that enabled Torres to do at 41 what she couldn't do at 14. It purports to protect the muscle, but there's not much science to show that it works. In fact, most of the studies that I've seen say it doesn't work--to the practitioner's detriment.
Muscles, as we have seen do indeed undergo lengthening contractions. But the consequences of routinely using lengthening contractions--in muscles where this was not intended as normal function--are less clear. What literature there is on this subject tends mostly towards the opinion that lengthening contractions actually cause damage to the muscle, albeit on the microscopic level. One study purports to demonstrate that stretching a muscle after it's fully contracted results in greater force generated, but that is hardly the same thing.
As of now, the evidence is against resistance stretching being the key to Torres's amazing performance. And so the skeptics look at her doping non-history. Frankly, no, I don't think she's doping, but it wouldn't surprise me if it later came out that she was. But I still think the best explanation for her success is practice. Tons of it. And being gifted with a freak genetic makeup that makes her so damn good at what she does--this blog does an adequate job summarizing a WSJ article that is no longer online--like so many other elite athletes.
There's a saying in the sports world that anybody who wants to make it as a major athlete must choose his parents wisely. As of now, we haven't quite figured out what makes Torres so freakishly good at what she does (maybe it's her telomeres), but that, I think, would be an interesting next step, much more so than the questionable (at the very least!) "benefits" of resistance stretching.
And for what it's worth: if someone could point me to a good study about resistance stretching and how it works, I'd be open to revising my opinion on it.
*Actually, I have some issues with publishing pictures of people online--I know I'd want permission before my photograph went up, and I feel obligated to extend the same courtesy to thers.