Beyond Miles Per Week: A New and Improved Way to Monitor Your Training

By measuring biomechanical stress, you may be able to reduce injuries and improve training and racing, says a new paper.

Photo: Getty Images

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Ask most runners how their training is going, and one of the first things you’ll find out is a number: the miles per week they’re putting in. A recent journal article suggests a new and possibly better way to monitor your running beyond miles. If implemented, this system offers more insight into your total training stress, so you are less likely to overtrain and more likely to peak as you want. The result? Higher fitness, fewer injuries and better results on race day. 

The paper doesn’t present new data or results from a randomized controlled trial, or any other experiment. Instead, it’s theoretical. It puts forward the authors’ beliefs, backed by the available evidence. And their position, while novel, will likely make intuitive sense to most runners.

Missing Major Metrics

shot of runners feet in a race
Photo: Miguel A. Amutio / Unsplash

Here’s the basic argument: If you monitor your running only by adding up total miles per week, you’re missing two key pieces of information. First, you’re failing to measure the intensity (i.e., pace, or effort) of your daily and weekly training load. 

This isn’t anything new. Coaches and runners have always recognized that intensity makes a difference. That’s why some, but not many, use TRIMPS (training impulses), or heart rate, or perceived exertion to distinguish the differences between a 2-mile warmup and the 2 miles of 8 x 400 that might follow. 

The second key piece of information is less commonly considered. The recent paper, published in the Journal of Orthopaedic & Sports Physical Therapy, turns more innovative when Max Paquette and co-authors delve into the biomechanical stresses associated with running. This is important new turf that will resonate with experienced runners.

Swimmers don’t have to concern themselves with mechanical stress. Cyclists don’t think about it. Nordic skiers and rowers give it little thought. But runners? We live in a different and more complex world. “Pounding” is our everyday companion, and it’s not always a good friend.

Paquette, director of Musculoskeletal Analysis Lab at the University of Memphis, is a biomechanist and former world class steeplechase runner for Canada. He understands pounding. His wife, American distance runner Lauren Paquette, ran the 1500/mile in college (a decade ago) and has now transitioned to longer distances. This year, she set personal bests for 5000 meters (15:10.1) and 10,000 meters (31:53.72).

“When training is only quantified using weekly mileage, that’s a gross misrepresentation of mechanical stress applied to the body,” Max Paquette told me. To improve how you monitor your running, the paper argues that coaches and runners should measure the amount of pounding in each week’s training. 

Simple Solution: Steps

There are complicated ways to do this in the lab, as well as more and more “wearable” monitors that claim to measure various forces. But Paquette believes there’s also a simple, yet useful solution: Count your steps per training session. And his new paper offers an informative example of how this might work.

Consider three 10K training runs—a “fresh” recovery run, a “very tired” recovery run, and a track workout of 10 x 1K in spikes. We all know the track repeats will give the biggest boost to your fitness, and can be measured by heart rate. Paquette rates it at about 95% of max heart rate versus 80% for the “very tired” run and 70% for the “fresh” run. (See below.) 

But it’s the step count and pounding (accumulated ground reaction force) that are most eye opening, because the very tired run scores highest on these metrics. During this kind of run, your muscles, tendons, and ligaments are so fatigued that you can’t produce a normal stride length. As a result, you run slower and take more steps, with each one increasing the total pounding on your already weakened body. If the only thing you note in your training log is the total distance of 6.2 miles, you’re missing some potentially crucial data.

Three Similar Runs, Briefly Analyzed

Fresh 10K Very Tired 10K 10 x 1K, track
Time 37:30 43:20 27:30
Heart Rate 70% max 80% max 95% max
Steps 6,750 7,669 5,445
Pounding 20,925 22,240 17,969

It’s important to note two things at this point. First, Paquette emphasizes that this is a theoretical model of how mechanical stress might interact with improved training. He’s currently conducting trials to see if “real world” data supports his ideas. Second, total pounding is affected by lots of variables, including: how fast you run, the shoes you wear, uphills and downhills, and more. No one has yet to derive a formula for how to combine all of these factors.

Still, Paquette believes step-counting has merit. “We recommend that coaches think more biomechanically,” he says. “The easiest proxy, to me, is step count. I bet if coaches started to monitor training volume with step count per training cycle, it might move the needle toward better training progressions with reduced overuse injuries.”

Evaluating Effort

Man running on road shirtless with a hat.
Photo: Issac Wendland / Unsplash

That still leaves an additional problem, noted above, with regard to counting only miles. How do you factor in intensity (pace)? You could multiply your miles by your average heart rate, yielding a number like 6 x 150 = 900 for one 6-miler, and 6 x 140 = 840 for another. Or you could investigate various proposed TRIMP methods, or even devise one that seems to suit you well.

Paquette likes session Relative Perceived Exertion (sRPE). By this method, you assign an effort number to each run you do. Most find it easiest to use a 1 to 10 scale, where 2 = easy, 3 = moderate, 5 = hard, 7 = very hard, and 10 = all-out race.

Runners addicted to gizmos find it hard to accept a “number” they invent on their own. But sRPE is proven to have a high correlation with heart rate and lactate production. It’s got a big additional benefit: By its very nature, it includes a host of key background factors such as sleep, diet, weather, hydration, family stress, work stress, and so on.

Using sRPE,  you might score one moderate 6-mile run as 6 x 3 = 18, and a harder one as 6 x 5 = 30. Ratings of 7 through 10 are reserved for high-end workouts and races. Systems like this are most useful when used over many months or years. That allows you to make internal comparisons of current training and performance vs. past efforts. 

“For a monitoring of training response, session RPE or ‘how you feel’ is clearly an underutilized approach to monitor training,” says Paquette.

Combine it with a measure of biomechanical stress, and you’ve taken a big step forward from the old-school, miles-only method. The next time your running buddy asks about your training, for simplicity you may still cite your miles, but you’ll know what kind of miles they were, and that makes all the difference.

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