Key points

  • Load in AU = session duration in minutes × RPE on a scale from 0 to 10 (Foster et al., 2001).
  • The classic approach is to ask about 30 minutes after the session; ask each athlete individually, not out loud in the group.
  • sRPE measures internal load and is considered valid in many sports; it does not capture the details of external load.
  • Monotony and strain (Foster, 1998) describe the week; Foster refers to individual thresholds, not general cutoffs.
  • AU are for comparing an athlete with themselves, not for ranking athletes against each other.
  • Tletify calculates daily load, monotony and strain automatically; only coaches with Pro or Team see monotony and strain.
The basics

What is session RPE? Foster's sRPE method

sRPE stands for session rating of perceived exertion: how hard an entire training session felt. After training, the athlete gives a single number for how hard the session was overall. Multiplied by the duration, that number gives the training load. The key paper for the method is Foster et al. (2001).

The authors tested it in cycling, with steady and interval efforts, and in basketball, comparing it with a heart rate–based method. Their conclusion: a valid way to quantify training across very different types of exercise. What it measures is internal load, meaning how demanding the session was for the athlete, not how much work was done.

The scale runs from 0 to 10. It is based on Borg's CR-10 scale (Borg, 1982), whose verbal anchors Foster et al. adapted for the sRPE method. The higher the number, the harder the session. Because it only needs this number and the duration, the method works across very different types of training, from strength work to team practice.

The calculation

Calculating training load: duration times RPE

To get the load of a session, multiply its duration in minutes by the RPE the athlete reports. Studies calculate sRPE load the same way, for example in soccer (Impellizzeri et al., 2004). The result has no physical unit and is expressed in arbitrary units (AU).

Load (AU) = session duration (min) × RPE (0–10)

An example: a strength session lasts 60 minutes, and the athlete rates it RPE 6. The load is 60 × 6 = 360 AU. An easy 45-minute session at RPE 4 gives 180 AU, while a long, hard 90-minute session at RPE 8 gives 720 AU.

If an athlete trains twice in one day, calculate each session separately and add both to the daily load. The daily loads of a week add up to the weekly load. These values are the basis for monotony and strain as well as the acute:chronic workload ratio (ACWR). For coaches, this means two numbers per session build a data series across the whole season.

Athlete sitting on the track, talking to his coach, who is holding a tablet
Collecting ratings

When and how to ask for the RPE

Traditionally, the RPE is collected about 30 minutes after the session so that the last few minutes don't unduly influence the rating (Foster et al., 2021). The rating depends less on timing than you might think, though: in a cycling study with 15 participants, Christen et al. (2016) found no significant differences between 5 minutes and 24 hours afterward, and Foster et al. (2021) describe the rating as robust from 1 minute to 14 days.

Christen et al. do point out that whether there is a cool-down may matter. What counts more than the exact minute is that the athlete rates the whole session, not just the last sprint. Explain the scale before you collect the first ratings: athletes should be familiar with it (Haddad et al., 2017).

Ask each athlete individually, not out loud in the group: who else is present when you ask, if anyone, affects the rating (Haddad et al., 2017). And rely on the athlete's rating rather than your own estimate: in a study with swimmers, coaches rated easy sessions lower and hard sessions higher than the athletes did (Wallace et al., 2009).

The research

How well does session RPE capture training load?

The method has been tested in many sports. In 19 young soccer players, sRPE load over 479 sessions correlated with heart rate–based loads at r = 0.50 to 0.85 (Impellizzeri et al., 2004). In 12 swimmers, correlations ranged from r = 0.55 to 0.94 (Wallace et al., 2009). In resistance training, Day et al. (2004) found high reliability in 19 people (ICC 0.88).

A meta-analysis of 13 studies with 295 team sport athletes found a correlation of r = 0.79 between sRPE load and total distance (90% confidence interval 0.74 to 0.83), and r = 0.63 with accelerometer load (McLaren et al., 2018). Reviews describe the method as valid, reliable and very useful in the field (Haddad et al., 2017) and as a well-accepted marker of internal training load (Foster et al., 2021).

The limit lies in how the method is built: sRPE measures internal load, not external load. The number doesn't tell you how many kilometers, jumps or kilograms were behind a session. It is not ideal for precisely recording the details of external load (Foster et al., 2021). If you need those details, track them separately.

Weekly load

Weekly load, monotony and strain in a sample week

From the daily loads of a week, Foster (1998) derived two metrics. Monotony is the week's daily mean divided by the standard deviation of the daily values, so it rises the less the days differ. Strain is weekly load times monotony and becomes high when a week brings a lot of load and is uniform at the same time.

Foster followed 25 experienced athletes in an observational study. A high percentage of illnesses could be accounted for by periods in which individual athletes exceeded individually identifiable training thresholds, mostly related to strain. So Foster describes individual thresholds, not general cutoffs: the study gives no value above which monotony or strain becomes critical for everyone.

DayDuration (min)RPE (0–10)Load (AU)
Monday606360
Tuesday607420
WednesdayRest day–0
Thursday607420
Friday454180
Saturday908720
SundayRest day–0
Week315–2,100

Sample week with five sessions and two rest days; load = duration × RPE

Weekly load: 2,100 AU. Daily mean: 2,100 ÷ 7 = 300 AU. Standard deviation: 240 AU, calculated as in Tletify and the template: the population standard deviation of all seven daily values (denominator 7, not 6). Monotony: 300 ÷ 240 = 1.25 (no unit). Strain: 2,100 × 1.25 = 2,625 AU. The rest days enter the calculation as 0 AU.

If the same athlete spreads the 2,100 AU over six sessions of 300, 315, 315, 360, 360 and 450 AU with just one rest day, the standard deviation drops to about 131 AU. Monotony rises to 2.29 and strain to 4,809 AU, with the same weekly load. How to distribute load over weeks and months is covered in our guide to periodization.

Avoiding mistakes

Typical mistakes with the session RPE method

The math is quick; mistakes happen when collecting and interpreting the numbers. A typical one is the wrong scale: the sRPE method uses 0 to 10. The 6-to-20 RPE scale is a different scale, and its values shouldn't be mixed with ratings from 0 to 10. Translated versions of a scale can also affect its reliability (Haddad et al., 2017).

Another is using sRPE for everything. As described above, the number doesn't show the details of external load. A load metric is only useful if it is plausibly linked to the response you care about (Impellizzeri et al., 2023). For kilograms, jumps or distance, you need separate measures. Other typical mistakes at a glance:

  • Asking right after the last interval, without a cool-down
  • Asking out loud in the group, so everyone hears the answers
  • Estimating effort as the coach instead of asking the athlete
  • Using AU to rank athletes instead of tracking each athlete over time
  • Treating monotony or strain as a fixed cutoff for everyone
Coach overview in the app with average readiness, ACWR value, sessions and next competition
In Tletify

How Tletify calculates with session RPE

In Tletify, athletes rate the intensity as RPE when they complete a session, under “Give feedback,” on a scale up to 10; the rating is optional. So Tletify asks when the session is completed, not 30 minutes later. That differs from the classic standard, but the studies on timing suggest it changes the rating little. Ask your athletes to rate the whole session, not just the last few minutes.

When data is thin, Tletify deliberately makes no statement about load: with fewer than 8 completed sessions in 28 days, or if fewer than half of them have a real RPE, it shows “Not enough data.” From a monotony of 2.0, Tletify points out a very uniform week. Tletify set this threshold itself; it does not come from Foster's study.

Only coaches with Pro or Team see monotony, strain and ACWR; athletes never see them in their interface. The metrics support your decisions and do not replace a medical assessment. What else Tletify derives from daily load is covered on the training load management page. The calculation rules at a glance:

  • Daily load = sum of duration × RPE of completed programs, in AU
  • Rest days count as 0 AU
  • No RPE: the athlete's average RPE over the last 90 days (at least 3), else RPE 5
  • Tonnage and ground contacts tracked separately, never combined with sRPE load
  • Monotony capped at 10, for example when every day is the same

Template: sRPE, monotony and strain

The spreadsheet calculates the way Tletify does: you enter the date, duration and RPE for each session, and it derives daily and weekly load, monotony (capped at 10) and strain. Days without a session count as 0.

Download the template (.xlsx)

Questions and answers

What is the difference between per-set RPE and session RPE?

Per-set RPE describes how hard a single set was; in the app's workout mode, effort per set can be logged as RPE or RIR. Session RPE, by contrast, rates the whole session in hindsight and, combined with duration, gives the training load. For daily load in Tletify, what counts is the RPE the athlete enters at completion under “Give feedback.”

Why shouldn't AU be used to rank athletes?

AU are arbitrary units based on each athlete's own rating. So 400 AU for two athletes don't necessarily mean the same load. Compare each athlete with their own values over weeks and months. This recommendation follows from the concept of internal load (Impellizzeri et al., 2019).

Does session RPE work for strength training?

Yes. Day et al. (2004) tested the method in 19 people during resistance training and found high reliability (ICC 0.88). Fewer reps at a higher intensity were perceived as harder. Session RPE doesn't show how many kilograms were lifted, which is why Tletify tracks tonnage separately as mechanical load.

How are session RPE and the ACWR related?

The ACWR compares the load of the last few days with the load of the last few weeks. Tletify calculates it from the same daily load in AU, by default with the uncoupled EWMA model using 7 acute and 28 chronic days. How the ratio works and where its limits lie is explained in our guide to the ACWR.

References

  1. Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc. 1982;14(5):377-381. doi:10.1249/00005768-198205000-00012
  2. Christen J, Foster C, Porcari JP, Mikat RP. Temporal robustness of the session rating of perceived exertion. Int J Sports Physiol Perform. 2016;11(8):1088-1093. doi:10.1123/ijspp.2015-0438
  3. Day ML, McGuigan MR, Brice G, Foster C. Monitoring exercise intensity during resistance training using the session RPE scale. J Strength Cond Res. 2004;18(2):353-358. doi:10.1519/R-13113.1
  4. Foster C. Monitoring training in athletes with reference to overtraining syndrome. Med Sci Sports Exerc. 1998;30(7):1164-1168. doi:10.1097/00005768-199807000-00023
  5. Foster C, Florhaug JA, Franklin J, Gottschall L, Hrovatin LA, Parker S, Doleshal P, Dodge C. A new approach to monitoring exercise training. J Strength Cond Res. 2001;15(1):109-115. PMID 11708692
  6. Foster C, Boullosa D, McGuigan M, et al. 25 years of session rating of perceived exertion: historical perspective and development. Int J Sports Physiol Perform. 2021;16(5):612-621. doi:10.1123/ijspp.2020-0599
  7. Haddad M, Stylianides G, Djaoui L, Dellal A, Chamari K. Session-RPE method for training load monitoring: validity, ecological usefulness, and influencing factors. Front Neurosci. 2017;11:612. doi:10.3389/fnins.2017.00612
  8. Impellizzeri FM, Rampinini E, Coutts AJ, Sassi A, Marcora SM. Use of RPE-based training load in soccer. Med Sci Sports Exerc. 2004;36(6):1042-1047. doi:10.1249/01.MSS.0000128199.23901.2F
  9. Impellizzeri FM, Marcora SM, Coutts AJ. Internal and external training load: 15 years on. Int J Sports Physiol Perform. 2019;14(2):270-273. doi:10.1123/ijspp.2018-0935
  10. Impellizzeri FM, Shrier I, McLaren SJ, et al. Understanding training load as exposure and dose. Sports Med. 2023;53(9):1667-1679. doi:10.1007/s40279-023-01833-0
  11. McLaren SJ, Macpherson TW, Coutts AJ, Hurst C, Spears IR, Weston M. The relationships between internal and external measures of training load and intensity in team sports: a meta-analysis. Sports Med. 2018;48(3):641-658. doi:10.1007/s40279-017-0830-z
  12. Wallace LK, Slattery KM, Coutts AJ. The ecological validity and application of the session-RPE method for quantifying training loads in swimming. J Strength Cond Res. 2009;23(1):33-38. doi:10.1519/JSC.0b013e3181874512

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