NYT on the "value" of cross training for runners

New York Times - August 15, 2011


Perks of Cross-Training May End Before Finish Line


By GINA KOLATA


The question has occurred to many endurance athletes, and it seems so basic: Will cross-training — doing a second sport, or lifting weights on days when you aren’t running or cycling or swimming — improve your performance in your primary sport?

And at first glance, the answer might seem to be an obvious no. If you want to be a better runner, you have to run — regularly, consistently, and with a training plan that forces you to gradually increase your distance and speed. If you want to be a better cyclist, you have to ride and train according to the same principles. Same goes for swimming or any other endurance sport.

But there also is a body of opinion that says cross-training is necessary and important if you want to improve your performance and avoid injury.

The science, though, is not nearly so definitive. And the answer as to what, if anything, cross-training can accomplish depends on your goal.

The American Orthopedic Society for Sports Medicine encourages cross-training, saying that it can provide a “ ‘total body tune-up,’ something you won’t get if you concentrate on just one type of activity,” and that “you may experience fewer overuse injuries.”

The American College of Sports Medicine’s guidelines for most Americans advise doing some of everything: exercises that increase your heart rate, weight lifting, stretching and balance exercises.

But the purpose of its recommendations is overall health, not performance. If that is your goal, researchers say, it is not so clear that cross-training in an alternate sport will help.

Hirofumi Tanaka, an exercise physiologist at the University of Texas in Austin, came to that conclusion more than a decade ago in a review of published papers. Studies comparing athletes, both trained and untrained, had found that only one factor mattered if performance was the goal: training in that sport.

Since then, he said, there have been numerous small studies, asking the same question and coming to the same conclusion. For example, two subsequent recent studies — one involving moderately fit runners and the other trained runners — found that adding cycling to a running program did not improve running performance.

The results make sense, Dr. Tanaka said. Each sport uses highly specific muscles and nerves. Using an elliptical cross-trainer may feel as if it is exercising your running muscles, but it is not giving you the same kind of training that running does. Nor does it train the muscles you need for cycling.

“You can maintain your cardiovascular capacity by cross-training, but it is extremely difficult to maintain your performance when you rely on cross-training,” Dr. Tanaka said. “This is because you are violating the principle of the specificity of training.”

Anyone who has been injured and forced to do an alternate sport knows this already. If you cannot run and end up substituting workouts on a bicycle for running, almost invariably you will end up losing running speed and endurance.

But if an alternate sport doesn’t help endurance athletes, resistance training might. It’s a bit counterintuitive — if you are training for an endurance sport like running, your workouts increase your ability to perform the same motion over and over again but do not markedly increase your muscle strength.

Lifting weights is just the opposite — you do a few repetitions with the goal of increasing muscle strength and size. Yet in a review of published studies, Dr. Tanaka found that resistance training improved endurance in running and cycling. The effect occurred both in experienced athletes and in novices.

A more recent study of experienced runners by a group of Norwegian researchers confirmed that weight lifting could increase performance. One group did half squats with heavy weights three times a week while continuing a running program. The other group just ran. Those who did the squats improved their running efficiency and improved the length of time they could run before exhaustion set in.

Similar studies also have found the effect in cyclists, but not in swimmers, Dr. Tanaka said. Swimmers do get faster, however, when they try a very specific type of resistance training, done while in the water, that concentrates on the movements they use in their strokes.

It is not known why weight lifting would improve performance, but investigators speculate that it may train supporting muscle fibers in the legs, allowing runners or cyclists to use them to augment muscles that get tired.

In swimmers, the investigators say, the research suggests that mastery of the highly technical swimming stroke is the most important factor in performance and endurance. Upper-body strength plays at best a minor role.

But even when cross-training doesn’t improve performance, might it prevent injuries? It’s a difficult question to answer, because it is not easy to do the necessary studies.

Dr. Willem van Mechelen, head of public and occupational health at VU University Medical Center in Amsterdam, looked at data on injuries in runners and tried to tease out the factors that were linked to them. And he concluded that the only way to prevent running injuries is not to run.

The harder you run and the longer your running distances, the more likely you are to get injured. And, he wrote, among the factors “significantly not associated with running injuries” is “participation in other sports.”

Unless cross-training means you simply do less of your primary sport, then, don’t expect it to protect you from injuries.

I think the line about how cross-training maintains (I'd say builds, in some cases) cardiovascular health/endurance says it all. Sport specificity is, of course, the best way to train for a sport. But raising the heart rate and teaching your body to endure that stress is pretty universal, regardless of which muscles are in play.

I don't know if any of these researchers have studied much regarding the link between max power and across-the-board performance increases, but that's something that most running/cycling coaches seem to support at this point, so the weight lifting thing doesn't surprise me at all.

Cross training should compliment running, but not supplant it.

Mike MacLellan wrote:
I don't know if any of these researchers have studied much regarding the link between max power and across-the-board performance increases, but that's something that most running/cycling coaches seem to support at this point, so the weight lifting thing doesn't surprise me at all.

This was kind of my line of thinking. If your muscles are stronger, then in theory they don't have to work as hard to perform a certain activity. They should then be able to do that activity more times before exhaustion. The article on a whole makes perfect sense to me.

I've been doing x-training and fewer running days since June, to try and get past the PF, and it is working, but I definitely feel slower in my running, with less endurance. I've been increasing the running the last couple of weeks, and I think that the good cardio base I maintained by including the x-training is helping me to get a bit of pace back more quickly than I would otherwise. The article makes sense to me, though I don't know why anyone would be surprised that strength training would work.

I don't see any value of the article. Not that I disagree, but come one, tell me something new.

These guys are all studying the wrong thing.

The purpose of the cross training is so that you DO spend LESS time in your primary sport thus reducing injuries. In addition, the cross training activities provide the same or more cardiovascular benefit that you would get from the lost time in your primary sport. Since the cross training is not stressing the same specific muscle groups, the primary sport muscles have more recovery time to rebuild and grow stronger. This allows the athlete to structure their plan to train harder in the primary sport without the usual associated risk of injury.

2 cents

Take injury out of the equation...



If a runner is currently averaging 10 hours per week running, and finds s/he has another 2 hours per week to devote to exercise... would x-training improve running performance MORE than spending that additional time running? I think not.



That said, if a given runner has a known injury concern... then yes, x-training is better than running oneself into an injury. You should run as much as your body can handle... and no more. If you are running as much as your body can handle, and you have more time available for exercise, definitely x-train.



My 2 pesos (less than 2 cents).

T Miller wrote:These guys are all studying the wrong thing.

The purpose of the cross training is so that you DO spend LESS time in your primary sport thus reducing injuries. In addition, the cross training activities provide the same or more cardiovascular benefit that you would get from the lost time in your primary sport. Since the cross training is not stressing the same specific muscle groups, the primary sport muscles have more recovery time to rebuild and grow stronger. This allows the athlete to structure their plan to train harder in the primary sport without the usual associated risk of injury.

2 cents

Tim, I think you've hit the nail on the head, though your second sentence may overstate the case. If you are one of the very few that can run and run and not get injured, just running (and strength training, but I regard that as routine body maintenance) will get the best results. But most of us are limited in the amount of running we can do without injury. We, the majority, are the ones who benefit from cross training. It is a way of adding training, beyond what we can endure uninjured if we stick to running.

Damn! While I was typing this, Matt just expressed what I wanted to say, but much better. I guess I'll post anyway :-)