How Peak Hybrid counts a lift in your training load

The short answer

Peak Hybrid scores a lifting session as minutes × (RPE ÷ 10) × 0.8, where RPE is how hard your sets felt on a scale of 1 to 10. A 60 minute session at RPE 7 scores 34. RPE counts as at least 6, and a dense session with short rest scores higher, so the score follows how much work you packed in as well as how hard it felt.

Why lifting needs to count

A heavy leg session leaves fatigue that can lower endurance performance for hours to days afterward (Doma 2017). In 1 trial, trained runners lifted and then ran 6 hours later. Their economy below threshold held steady, while their time to exhaustion above threshold fell after the heavy sessions (Doma and Deakin 2014).

Since that fatigue carries into your next ride or run, Peak Hybrid counts it. Your lifting and your endurance sessions share 1 scale, so a heavy leg day and a long ride add up in the same week. Fitness, fatigue, and form are built from that combined load. Without the lift, your form would read fresher than your legs feel on the day after leg day.

The formula

The lift score uses 2 inputs, the length of the session and how hard it felt.

Minutes is the length of the session, rest included.

RPE is the average of the RPE you log on your sets. It counts as at least 6 and at most 10.

0.8 is a fixed factor applied to every lift. Most of a lifting session is rest, so even an hour at RPE 10 scores 48.

Some worked examples, using the formula as written:

• 45 minutes at RPE 8 scores 29.
• 60 minutes at RPE 7 scores 34.
• 60 minutes at RPE 10 scores 48.

Measuring a session by how hard it felt has been tested against heart rate. In 1 study, a rating of the whole session matched a heart rate method consistently in cycling and in basketball, and the authors judged it a valid way to measure many types of training (Foster 2001). The lift formula draws on the same 2 inputs, time and effort. That study did not test lifting, and the 0.8 factor and the RPE floor are Peak Hybrid's own choices rather than values from a study.

Why RPE counts as at least 6

A logged RPE under 6 counts as 6. A session with no working reps logged also counts at RPE 6, and so does a lift recorded outside the app, in Strava or Apple Health. That works out to minutes × 0.6 × 0.8, so a 60 minute lift that comes in from Strava scores 29.

The floor means a lifting session always adds a real amount to your load, even when you rate your sets as easy.

How density raises the score

A circuit with short rest packs more work into each minute than a heavy session with 3 minutes between sets.

Peak Hybrid measures this as density, the share of the session spent working. Each working rep counts as 3.5 seconds of work, and timed sets count their logged time. When work fills more than 15% of the session, the effective RPE climbs 1.33 for every 10 points of density above that, up to 10.

Density only ever raises the score. When your logged RPE is higher, your logged RPE wins.

As an example, a 40 minute session with 200 working reps has about 29% of its time spent working. Density raises its RPE to about 7.9. If you logged RPE 7, the session scores 25 in place of 22. A 60 minute session with 120 working reps is about 12% work, under the 15% line, so a logged RPE of 7 stands and it scores 34.

How a lift sits next to a ride or run

Rides and runs use a different formula, hours × intensity² × 100. Intensity comes from power on a ride with a power meter, from heart rate on other rides and runs, and from your effort rating on a session you log by hand. 100 is 1 hour at your threshold, and because intensity is squared, a hard hour counts for far more than an easy one.

Some examples on the same scale:

• 2 hours of endurance riding at an intensity of 0.65 scores about 85.
• 1 hour at threshold scores 100.
• A 60 minute lift at RPE 7 scores 34.

Per hour, a lift scores less than hard riding or running. An hour of lifting at RPE 10 scores 48, while an hour at your threshold scores 100.

A day with both, a 60 minute lift at RPE 7 and 2 easy hours on the bike, adds up to about 119. The lift is a smaller share of the day than the ride, and it still moves your fatigue and form. The article on fitness, fatigue, and form shows how a heavy leg day shows up in form.

How Peak Hybrid uses it

Every lift you log in the app gets a score from this formula. On Full Body or Strength for Cyclists, your strength sessions land on the same calendar as your rides and runs and count toward the same training load. The formulas and the fine print are on the method page, and the load calculator lets you enter your own lift and ride and see 6 weeks of the result.