Session RPE training load for lifting and running

Session RPE training load is your rating of the whole session, 0 to 10, taken about 30 minutes after you finish, multiplied by the session's length in minutes. A 60-minute lift you rate 7 is 420 units. A 40-minute easy run you rate 3 is 120. It's the simplest way to put a squat day and a tempo run on the same scale, which is exactly the problem a hybrid athlete has.

How the method works#

Carl Foster's group described and tested the method in a 2001 paper. About 30 minutes after a session, you look at a 0 to 10 scale and answer one question: how was your workout? The delay is deliberate, so a brutal last interval or an easy cool-down doesn't swamp your rating of the whole thing. Then you multiply that number by the session's duration in minutes.¹

The scale is a modified version of Borg's CR-10. These are the anchors as Haddad's review lists them:²

6, 8 and 9 have no label, but they're valid ratings. Borg's category-ratio scales track rising effort closely: in his lab comparison, ratings on them correlated at about 0.97 to 0.98 with step-wise increases in cycling workload.³

Haddad's review found 36 studies testing the validity and reliability of session RPE against other measures, across sports, ages and levels, and concluded it holds up well enough to be used on its own, though some authors pair it with heart rate.² The units are arbitrary. They only mean something compared with your own other sessions.

Why it suits a hybrid week#

Most load measures belong to one sport. Kilometres and pace mean nothing for a deadlift. Tonnage means nothing for a run. Heart rate does a decent job on steady cardio, but Halson's review notes RPE and heart rate agree well in steady and interval cycling and less well in short, high-intensity soccer drills.⁴ A set of heavy squats looks a lot more like the drill than the ride.

Session RPE doesn't care what the session was. Foster's original paper tested it on steady cycling, cycling intervals and basketball practice, and found the relationship with a heart-rate method stayed consistent across all of them.¹ For lifting specifically, Haddad's review lists resistance-training studies with high test-retest reliability (intraclass correlations of 0.88 and 0.95).² That's the case for it: one number, any session.

What my own numbers look like#

I've only logged RPE on my HYROX circuits, not on lifts or runs, so that's the data I have. Here are the longer ones from July and early August 2026, with session RPE load worked out as RPE times the logged minutes.

Ken's HYROX circuits: session RPE load

	Value (AU)
6 Jul · Run/Wall, 41 min, RPE 8	328
8 Jul · Row/SkiErg, 52 min, RPE 7	364
11 Jul · Run/Burpee, 54 min, RPE 7	378
14 Jul · Run/Wall, 38 min, RPE 8	304
15 Jul · Row/SkiErg, 43 min, RPE 6	258
21 Jul · Run/Wall, 29 min, RPE 8	232
24 Jul · Row/SkiErg, 18 min, RPE 6	108
30 Jul · Run/Wall, 29 min, RPE 6	174
4 Aug · Run/Wall, 27 min, RPE 6	162

Load = logged RPE x logged minutes. Source: Ken's own sessions in hybridAF, 6 July to 4 August 2026, read from the database on 22 October 2026.

Two things stand out. The ratings sit in a narrow 6 to 8 band, so minutes drive most of the difference between sessions. And a shorter session at a higher rating can carry less load than a longer one at a lower rating: RPE 8 for 29 minutes is 232, RPE 7 for 54 minutes is 378. For scale, Gabbett reports that session RPE loads in football codes generally run 300 to 500 units for lower-intensity sessions and 700 to 1,000 for higher-intensity ones.⁵

The honest gap in that chart is the rest of my week. Without RPE on my lifts and runs, I can't add those circuits up into a weekly load. If you try this, rate everything, or the weekly numbers below won't work.

The weekly view: load, monotony and strain#

Once every session has a number, Foster's 1998 paper adds two more. Monotony is the average daily load divided by the standard deviation of daily loads across the week. Strain is the weekly load multiplied by monotony.⁶ Monotony is high when every day looks the same. In that study of 25 athletes, minor illnesses clustered when individuals went past their own training thresholds, mostly thresholds of strain.⁶ Haddad's review gives the same definitions.²

Here's a worked example. Both weeks total 1,620 units. Week A is a hybrid split with hard and easy days. Week B spreads the same work into six identical medium sessions.

Two weeks, same total load (1,620 AU)

	Value (AU)
Week A · Mon	420
Week A · Tue	120
Week A · Wed	0
Week A · Thu	400
Week A · Fri	360
Week A · Sat	320
Week A · Sun	0
Week B · six days	270
Week B · rest day	0

Worked example (illustrative numbers, not anyone's real data). Week A: lift 60 min RPE 7, easy run 40 min RPE 3, rest, intervals 50 min RPE 8, lift 60 min RPE 6, long run 80 min RPE 4, rest. Source: calculation using the session RPE method (Foster et al. 2001).

Same work, nearly double the strain, purely because Week B never lets up. The SD here is the standard deviation of the seven daily values; the sources don't specify which form, so treat the exact figures as an example of the arithmetic, not a target.

That's the most useful thing monotony does for a hybrid athlete. It's easy to fill a week with "moderate" sessions, a medium lift here and a steady run there, and feel like you're being sensible. The numbers say a week like that can carry more strain than one with genuinely hard days and genuinely easy ones.

The acute:chronic workload ratio, and the case against it#

The acute:chronic workload ratio (ACWR) compares your recent load with what you're used to. In Gabbett's 2016 paper, acute load is usually the last week and chronic load is the rolling average of the last 3 to 6 weeks. He described ratios of 0.8 to 1.3 as a "sweet spot" and 1.5 or above as a "danger zone" for injury risk.⁵ Those bands came from cricket, Australian football and rugby league, and Gabbett himself wrote that applying them to individual-sport athletes should be done with caution.⁵

Then the critique arrived. Impellizzeri and colleagues argued in 2020 that no study had even tried to estimate the causal effect of changing the ratio, that the ratio is statistically inaccurate and ambiguous, that it adds noise and creates statistical artifacts, and that there is no evidence supporting its use in load management or for injury-reduction advice.⁷

Where that leaves you: the plain idea underneath the ratio, that a week far bigger than what you've been doing is the one to be careful with, is reasonable training sense. The specific number, and the idea that a ratio of 1.5 tells you something precise about your risk, isn't supported. Use the trend in your weekly load as a sanity check. Don't use a ratio as a forecast.

Logging it in a mixed week#

The single-sport papers leave a few practical calls to you. Two sessions in one day get rated separately, each 30 minutes after it, and the loads added. A morning lift and an evening run are two sessions, not one long one.

A lift and a run in the same session is less clear. Foster's group found that about 80 to 90% of athletes give one number for the whole session, while the rest insist on rating the parts and adding them up.¹ Either works if you stick with it. Splitting is more useful for you, because it shows how much of the day's cost came from each half.

For HYROX sims and circuits, rate the whole thing and use its total minutes. In the chart above, the 54-minute run and burpee circuit tops the list on minutes, not on its rating.

Then compare. Look at this week's total next to the average of your last three or four weeks. That's the same acute and chronic idea as the ratio above, without pretending the division gives you a precise answer. If the week you're planning is much bigger than anything recent, that's the one to think twice about. If your totals have been climbing for a month and your sessions feel flat, that's the case for a lighter week.

Where session RPE goes wrong#

It's a rating, so it inherits everything that moves a rating. Haddad's review lists sex, age, fitness, experience, music, temperature, altitude, caffeine and fasting among the things that can shift RPE, plus a weak agreement between the load a coach planned and what athletes actually reported.² Halson adds that self-reported data can be over- or underestimated, and that no single load marker is definitive.⁴

For a hybrid athlete the main risk is consistency. If you rate lifts harshly and runs generously, your weekly total will lean whichever way you're biased. Rate at the same time after each session, use the anchors, and compare your numbers only with your own.

How the app's Strain differs#

hybridAF's Strain is a different thing with an unfortunately similar name. It's a day score built, for Apple Health data, from the active energy your watch records, run through a logarithmic curve on an internal 0 to 21 range and shown to you out of 100, with labels from Rest to Max. The curve and the cut points are our design choices, not a published standard. Because it starts from active energy, it under-reads heavy lifting, where the cost outruns what heart rate and movement show; we say so on the science page. The app lets you log RPE on a session, but Strain doesn't use it today. So if most of your week is barbell work, a session RPE log will see things Strain misses. The Today guide shows where Strain sits next to recovery.

Related reading#

Load is one half of the picture; the other is how you're absorbing it, which is what HRV for hybrid athletes covers. When the weekly numbers say you've been stacking strain, a planned deload week is one answer. And because session RPE depends on how hard you push each set, RPE, RIR and failure is the lifting side of the same question. The rest of the pillar is in the recovery hub.

Nothing here is medical advice. If training leaves you with pain, illness or symptoms that don't settle, see a clinician.