Thursday, March 12, 2009

Running Rules of Thumb

While reading Bart Yasso's My Life on the Run, I came across his predictor for marathon times, "Yasso 800s." Yasso was in the habit of doing a 10 x 800m track workout; his rest in between each item was a 400m jog. He noticed that his average 800m time (in minutes and seconds) in one of these workouts in the weeks leading up to a marathon was about the same as his marathon time (in hours and minutes). For example, if he averaged about 2:50 in a 10 x 800m workout five weeks before the marathon, he was in shape to run a 2:50:00 marathon. Yasso used this predictor in his own training, and there it would have stayed, but he mentioned it to Amby Burfoot. Burfoot asked around and confirmed that this seemed to be a good predictor for other runners as well. Burfoot wrote up this rule-of-thumb in Runner's World, chistened the 10 x 800m workout "Yasso 800s," and history was made.

Yasso is quick to point out that running a good 10 x 800m workout is not the only requisite to running a good marathon. You still have to do all the usual marathon preparation--long runs, repeat miles, more long runs, etc. In the language of statistics, there is a correlation between the 800m average and the marathon time, but no causal relationship. Most likely both a good 800m average and a good marathon time result from the same underlying cause of good marathon fitness. But it's a good way of testing what kind of marathon you are ready to run without actually running a marathon. Average 3:10 for your 800s in the weeks before the marathon, and you know to pace yourself for a 3:10:00 marathon on race day. Trying to run a 2:40:00 marathon? If you can't average 2:40 in your 10 x 800m workout, you're not ready.

Now, I don't know how good a predictor this is. Burfoot doesn't seem to have done any statistical analysis, or even any research other than asking a few running buddies about their workouts and marathon times. So we really can't say how strong a correlation this is. I'm also certain that there are a few outliers--for instance, Marcus Trigg, one one of my running partners in college, once said, "If 10 x 800m were an Olympic event, I'd be a gold medalist!" Marcus ran some good marathons, but not Olympic-champion good.

Still, it's a rule-of-thumb, and a nice quantitative rule-of-thumb at that. It made me wonder what other running rules-of-thumbs were out there. There are a few.

The Ten-Percent Rule

I had this one quoted at me when I was making yet another attempt to get back in shape: never increase your weekly mileage by more than ten percent. Any larger increase puts you at risk for an overuse injury. This was a casual conversation, though, so of course I wasn't given a source. Like Yasso 800s, it goes back to Runnner's World and Amby Burfoot. You can read one of his articles about it here.

Naturally, I hate this one. Who wants to patiently increase ones training only ten percent each week? Additionally, a logical consequence of the Ten-Percent Rule is that non-runners can never start running--ten percent of nothing is nothing. It's also hard to see how this could ever be tested experimentally, which would be key to determining if the actual maximum rate of increase was 8%, or perhaps 13.6%. If nothing else, it's nearly impossible to find two runners who agree on how mileage should be counted.

But it's a rule of thumb. And if it's a rule of thumb that keeps runners from getting strained muscles or inflamed tendons, then it's a good rule of thumb.

Gavuzzi's Law of Training ("Three hours slow is better than two hours fast.")

Pete Gavuzzi keeps popping up in the history of North American distance running. Born in Liverpool, he became a great marathoner at an early age, but is omitted from the history of British athletics for the sin of having run as a professional. Gavuzzi ran in both of C. C. Pyle's races across America in 1928 and 1929, won professional distance races on both sides of the Atlantic, and coached several Boston Marathon winners during the 1930s and 1940s. He shows up as a coach in the biographies of marathon greats such as Gerard Cote, Pat Dengis, "Jock" Semple, and Walter Young. One consistent bit of training advice he gave was that "three hours slow is better than two hours fast." That is, long training runs at a gentle pace were more effective than shorter runs of greater intensity in preparing for a marathon. This was revived in the 1960s as the "Long Slow Distance" school of training.

Faul's Rule

As a collegiate runner I'd occasionally get injured (possibly from having ignored the Ten-Percent Rule). Hope springs eternal, so we'd always trek to the training room when we were hurt. The trainers at Florida State University were good, but they were used to football injuries--crushed bones, fractured skulls, and those sorts of things. Injuries that you put a little tape on and then you're back in the game a play later. Hurt distance runners puzzled them. We were up and walking, we weren't bleeding, and no jagged ends of bone were sticking out of our flesh--how could we be injured? Still, Don Fauls, the head trainer, understood our pain and frustration at not being able to work out. "You lose fitness about four times as fast as you get it," he pointed out. Now, that's probably impossible to measure, but the numbers sounded good to me, so I've repeated it ever since.

Kilometers to Miles and Back

Multiply miles by 1.6 to get kilometers. Divide kilometers by 1.6 to get miles. Now, this arithmetic might be a bit unwieldy to do during a long run if you're not the Rain Man, so do it this way.

Miles to kilometers: start with the number of miles. Double it. Double it again. Double it a third time. Double it a fourth time. Now move the decimal point one place to the left. You've got kilometers.

Kilometers to miles: start with the number of kilometers. Move the decimal point one place to the right. Halve the number. Halve it again. Halve it a third time. Halve it a fourth time. You've got miles.

Metric Conversions

During my NCAA running career in the Bronze Age, there were quite a few 440-yard tracks left. It was easy enough to figure what three-mile time a given 440-yard split would give you, but what about that odd fraction of a lap you had to cover to make 5,000 meters? Our rule of thumb was that you covered this in 30 seconds. That is, add thirty seconds to a three-mile time to get a 5,000-meter time, subtract 30 seconds from a 5,000-meter time to get a three-mile time. This was a very rough approximation because we made no adjustment for pace. In fact, for the 10,000 meters, we just doubled the 30 seconds to one minute for a similar rule of thumb. Still, it let you get rough answers about pace when you needed them quickly (such as during a race). It also worked for road races, which even today are paradoxically marked off in miles in spite of the fact that all the distances are metric.

I don't remember any agreement about a similar rule-of-thumb for the 1,500 meters and the mile. Several runners on the team added 18 seconds to a 1,500 time to get a mile time. I used to add 20 (I was either more conservative or just slower). Either way, I was (and still am) a big fan of Sullivan's Law: A 1,500-meter time is not a mile time.

Strangely enough, none of these metric conversion rules of thumb seem to work for me anymore. Perhaps the laws of arithmetic have changed in the past thirty years?

The Gate-to-Gate Predictor

The Eglin Air Force Base Gate-to-Gate Memorial Day Run is an odd distance, 4.4 miles. Well, that's the distance from one gate of the base to another, so that's how far the race is. Of course, no one knows what kind of time they should be running for 4.4 miles. I was discussing this after the race one year, and came up with this. Take a recent 5K time (not your PR, but something that you could have run the day of the Gate-to-Gate race) and increase it by a half. There's your predicted time for Gate-to-Gate. For example, if you ran 19:00 three weeks ago, half of that is 9:30, so you should be able to shoot for 19:00 + 9:30 = 28:30 for Gate-to-Gate.

This rule-of-thumb seemed to work for the first three people I talked to, so I declared it a Law of Nature. Never mind that at least half of the people I subsequently discussed it with felt that it was at total odds with reality. Admittedly, there are a lot of variables. The weather, for one. And who really knows what kind of 5K time one is capable of running on any given day, let alone Memorial Day? To make matters worse, the course for the Gate-to-Gate Run has since been changed. It's still the same odd distance, but not the same hills and shade-free roads. In spite of that, if I'm ever at the start of the Gate-to-Gate run again, and some young runner wonders aloud what kind of time he should try to run, I'll know exactly what answer to give him.

That's it for the running rules-of-thumb that I've run across over several mis-spent decades. If you have any others, please pass them along.

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1 comment:

  1. I agree with you on the 10% rule, there is no good universal training rule for every person. We all have our own running styles and fitness levels. The most important thing is to just listen to your body and know when to rest. Here are some more thoughts on the 10% rule: http://www.seriousrunning.com/blog/

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