Doc’s Talk 06-03-2012

Dr. Scaff talked about stretching and how it contributes to injuries.

Running injuries are cumulative.  Dr. Scaff illustrated this by recalling a plane crash that occurred in Chicago where the plane lost part of its wing and an engine.  What caused the crash was metal fatigue, which had built up over time.  The same kind of thing can, over time, occur in the body and lead to injuries.  You have got to be constantly aware of this “cumulative effect”, …such as that which occurs with stretching

For various reasons people may not give Dr. Scaff credit for knowing what he is talking about when it comes to running, however, he did his first marathon in 1974, did every Honolulu Marathon until 1999, half of them completed in under 3 hours and 30 minutes, did one 50-mile run, and three 100-mile runs.  In 26 years he showed up at the start of every race without an injury and never had to withdraw.  How did he do that?  He watched the Honolulu Marathon Clinic every Sunday, and whenever he observed anything that led to an injury in someone, he quit doing that thing.  This is not to say that they did not make mistakes in the early days of the Honolulu Marathon Clinic, but they were observing, they were learning.

Running and cardiology are passions of Dr. Scaff’s, and he wants to be the best educated there is, the most knowledgeable, and if he finds out that he is not, he is going to learn more.  Therefore, he asks that you take some of what he says on faith, because you are going to hear a lot of controversy on these issues.

Dr. Scaff clarified that he is not against passive stretching.  After a run you can lean up against a telephone pole or things like that, however, sometime around 1978, there were several thousand runners in the Honolulu Marathon, and Dr. Scaff observed that the only runners that seemed to be stretching were the ones that were injured.  At the time, they did not know what this meant.  They speculated that people may start stretching after they are injured, or perhaps to prevent an injury, or perhaps even as a “penance” to get better.  Whatever the reason, there was a higher incidence of injury observable in runners who did stretching.

To learn more about this, the Honolulu Marathon Clinic worked with the University of Hawaii Department of Physiology and developed a questionnaire for a study.  In order to enter the Honolulu Marathon that year, a participant had to complete the questionnaire.  While some people discontented themselves about having to do this extra step, the resulting collection of information from all marathon participants provided for a good study population.  Before the University of Hawaii had gone very far into the study, they informed Dr. Scaff that the data showed that no matter WHY runners may stretch, those who stretch have a higher percentage of injuriesPeriod.

They published these findings and thereafter, Dr. Scaff was contacted by the New York Times for a series of interviews.  The New York Times eventually published a story on the findings that stretching results in a higher incidence of injuries in runnersThree more studies were done, and all three came to the same conclusion.

So flexibility and long distance running don’t really coexist, which might explain why a ballet dancer could not run a marathon; she has to be very, very flexible.  Dr. Scaff does not say that you don’t have to be flexible for some sporting events, like a hurdler, or be limber like a football player, but the same study shows that the less flexible the knee is, the less likely it is to get injured.

Thus, when you see football players doing all their stretches, they are actually increasing their chance of injury.  But, that is how mythology persists, just like people were once taught in high school that on hot days they had to eat salt tablets but should not drink liquids.  We know now we have to take salt and water, or pretzels, or something similar.

The Passive Effect of a Tight Hamstring
If you can touch your toes you are quite flexible.  If you can touch your knees, you are a good long distance runner.

When you put your foot down, there is a kinetic energy and you stretch the hamstring.  Then as you take your next stride, you stretch the hamstring and that kinetic energy comes back and increases your running power by up to 5%.  Like an elastic band, the more you pull it back the more elastic force you get out of it.  So being fairly tight, particularly in the hamstrings, is good.  If you are doing hamstring stretches, you could be running with two floppy rubber bands hanging down behind your legs that are not doing you very much good.

Passive Stretching
As previously noted, Dr. Scaff is not against passive stretching, and if you are going to stretch, you should warm up first.  (Warming up is described as any activity that raises the body temperature and working muscles up to 100 – 101º Fahrenheit.  You know you are warmed up when the first sign of perspiration appears on your foreheadAs a warm-up, the Honolulu Marathon Clinic recommends running very slow for the first 10 minutes of your run.)  After all, how can a muscle remember 5 minutes of passive stretching 5,000 steps (1 hour) later?  It can’t.  But if you want to stretch a little bit while you are standing waiting for your water or when you come back after a run, that’s ok too.

So, with regard to stretching, you do as you want, but that is the data as it has been published thus far.

There are several pages with useful information on stretching in Your First Marathon – The Last Word In Long Distance Running, by Jack H. Scaff Jr., M.D., F.A.C.S.M., available for purchase at the Honolulu Marathon Clinic on Sundays and online at:

Next Sunday, Dr. Scaff will continue on injuries, and will talk about shin splits and side stitches.


For some good reading on nutrition, Dr. Scaff recommends everyone check out the daily postings on Dr. Alan Titchenal’s “Got Nutrients?” web site:

Here is a recent posting:

May 30, 2012
If you are tired of consuming sugar-based sports drinks during your workouts, go bananas. A new study found that consuming bananas along with water during a 2.5 to 3 hour session of cycling provided the same performance benefit as consuming a sports drink that provided the same amount of carbohydrate.

Consumer Link
Bananas Are as Beneficial as Sports Drinks, Study Suggests

Research Link
PLoS ONE 7(5): e37479. doi:10.1371/journal.pone.0037479