How to Use Relative Effort to Refine Your Training

Multi-Sport

June 13, 2024

Relative Effort assigns a “score” to each activity you do, so you can better understand the cumulative effect of training.

How does your 3-hour ride at tempo pace compare to your local 5K running race? It’s a complex question, given that running and riding—not to mention all the other activities that you can record on Strava—take different levels of effort to perform. It is even more complex because high intensity training doesn’t have the same impact as low-intensity workouts, and vice versa. It’s all relative.

This brings us to a key Strava metric that can be used to refine your training: Relative Effort. Relative Effort measures how much cardiovascular work went into any activity, according to heart rate data or (manually-entered) Perceived Exertion.

A short, intense activity can require just as much effort as a long and mellow one, and Relative Effort makes it so you can compare the two. Just as importantly, different activity types are weighted so that your efforts can be compared across sports. Finally, because the metric is a function of your heart rate zones, each athlete gets a personalized “score” that can be compared with other athletes.

For example, if you and a friend ran your hardest marathon effort, your Relative Effort scores would be similar even if your finishing times were different.

How is Relative Effort determined?

It should be no surprise that, like many things these days, there’s an algorithm (or formula) behind Relative Effort measures how much cardiovascular work went into any activity, according to heart rate data or (manually-entered) Perceived Exertion.

The engineers at Strava created a model that takes in a stream of data—an athlete’s heart rate and a corresponding timestamp. Using the athlete’s max heart rate (either entered by the athlete or estimated), this heart rate data is divided into a number of zones that approximate different levels of cardiovascular intensity.

For each heart rate zone, the model applies a coefficient to weight the time spent in that zone. The higher the heart rate zone, the harder the effort, and a higher coefficient that more heavily weights time spent in that zone.

Relative Effort measures how much cardiovascular work went into any activity, according to heart rate data or (manually-entered) Perceived Exertion.

For those who have used Strava for a while, you may remember “Suffer Score.” The new Relative Effort model similarly uses the time you spend in different heart rate zones to score an activity. Now, however, there are a few key differences:

It weights the intensity of effort more than duration.
It is better at weighting equivalent efforts across sports.
It scores equivalent efforts by different athletes similarly.

The result is that we, as athletes, are better able to use Relative Effort to compare activity efforts across workout types, sport types, and even individuals.

Beyond Relative Effort

Taken in succession, Relative Effort accumulates over time. This Relative Effort graph of individual efforts shows the cumulative training load during a given week and indicates how you're trending week over week.

Shading provides a weekly “Relative Effort range,” a suggested range to target based on your three-week average. You can choose to aim within, above, or below your range depending on your training and goals.

Remember, sometimes you want to steadily build and stay within that Relative Effort range, but at other times you’ll want to do an overload block to spark “supercompensation,” or pull things back to recover.

Here’s a glimpse at the various trends to look for:

Within range: Your training is similar to your 3-week average, which can help build or maintain fitness while lowering the risk of overtraining.

Below range: You're taking it easy. (This isn't a bad thing.) Rest weeks are a great way to recover from big efforts or to gear up for more.

Above range: You're working more than usual this week. These big efforts can help lead to fitness gains—just be sure to follow them with proper recovery.

How to Use Relative Effort

By keeping an eye on Relative Effort, you can compare trends over time, which can help you determine when you need more rest. By following the 'recommended range' band, you can effectively determine whether you're building endurance fitness 'safely'.

Of course, in terms of performance keeping it within the range will be productive—to a point. Exceeding the range might make it seem like you’re overdoing it, but we need occasional peaks and valleys in order to build and recover. Doing the same training week after week will lead to stagnation.

Knowing the fundamentals of training can go a long way toward helping you determine what you need (a small, medium, or large Relative Effort score)—and when—to optimize your training. And, then, knowing how much an effort will “earn” in Relative Effort points further amplifies your training acumen. This helps you craft your weeks, which helps you craft your blocks, which helps you get from where you are to where you want to be for a key event.

It's worth saying that when you don’t have an event or goal on the horizon, though, it may be that Relative Effort is less useful for you. After all, focusing on the numbers too much can take away from some of the intrinsic value of riding for pleasure, and improving your sense of feel.

An occasional peek, however, won’t hurt, and can help you recalibrate your understanding of what you’re perceiving.

Written by

Chris Case

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