# Per-Olof Åstrand
**Per-Olof Åstrand** (1922–2015) was a Swedish exercise physiologist who co-developed the Åstrand-Ryhming nomogram (chart with scales letting you read a value graphically) for predicting maximal oxygen uptake from submaximal heart rate, co-authored the standard *Textbook of Work Physiology*, and served as professor of the physiology of physical exercise at the Gymnastik- och idrottshögskolan (GCI) in Stockholm from 1970 to 1977 and at the Karolinska Institutet from 1977 to 1989.[1](https://www.ne.se/uppslagsverk/encyklopedi/l%C3%A5ng/per-olof-%C3%A5strand) The Swedish National Encyclopedia describes him as a central figure in Swedish and international sports and work physiology.[1](https://www.ne.se/uppslagsverk/encyklopedi/l%C3%A5ng/per-olof-%C3%A5strand)
| Key fact | Detail |
|---|---|
| Life | 1922–2015; Swedish exercise and work physiologist[1](https://www.ne.se/uppslagsverk/encyklopedi/l%C3%A5ng/per-olof-%C3%A5strand) |
| Professorships | Gymnastik- och idrottshögskolan, Stockholm, 1970–77; Karolinska Institutet, 1977–89[1](https://www.ne.se/uppslagsverk/encyklopedi/l%C3%A5ng/per-olof-%C3%A5strand) |
| Doctoral thesis | *Experimental studies of physical working capacity in relation to sex and age*, presented to the Karolinska Institute Medical School in 1952 (Munksgaard, Copenhagen)[2](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf) • [3](https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0838.1991.tb00264.x) |
| Signature method | Åstrand-Ryhming nomogram, *Journal of Applied Physiology* 7:218–221 (1954), estimating aerobic capacity from pulse rate during submaximal work[4](https://www.physiolair.com/wp-content/uploads/2022/06/Special_Tests_of_the_Cardiopulmonary.pdf) |
| Textbook | *Textbook of Work Physiology* with Kaare Rodahl, first published 1970; fourth edition 2003, 649 pages[5](https://books.google.co.uk/books?id=BC9SiAsUPqsC) • [6](https://openlibrary.org/books/OL4907249M/Textbook_of_work_physiology) |
| Honors | ACSM Honor Award (1973); honorary Fellow of nine international societies; Fellow of the American Association for the Advancement of Science[2](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf) |
| Output | About 200 English publications; invited lectures in about 50 countries and 150 cities outside Sweden[2](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf) |
## Education and the Stockholm school
Åstrand graduated from the College of Physical Education in Stockholm in 1946 and is described by exercise physiology historians as its most famous graduate.[2](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf) His career took shape at the Royal Central Institute of Gymnastics (GCI), where the Danish physiologist Erik Hohwü Christensen had been appointed professor of physiology in 1941 and built a research program on the Copenhagen School's focus on basic physiology, bodily limits, and the rationalization of exercise.[7](https://www.diva-portal.org/smash/get/diva2%3A624136/FULLTEXT02.pdf) Applications in elite sports became a claim to fame for GCI through names like Per-Olof Åstrand and Bengt Saltin, although the institute's stated goal was the rational physical education of the whole population rather than athletic performance itself.[7](https://www.diva-portal.org/smash/get/diva2%3A624136/FULLTEXT02.pdf)
In 1952 Åstrand presented his doctoral thesis to the Karolinska Institute Medical School, published as *Experimental studies of physical working capacity in relation to sex and age*.[2](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf) • [3](https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0838.1991.tb00264.x) This work included maximal performance tests of female subjects at a time when such testing of women was widely regarded as dangerous and socially unethical; the results showed that a maximal test might not always be appropriate, since it could interfere with health in clinical populations and with athletes' training.[8](https://rplamberts.com/subpage-3-11/)
## The Åstrand test and nomogram
**Submaximal prediction of aerobic power.** Because maximal oxygen uptake (VO2max) testing is extremely demanding even for athletes and raises practical and ethical concerns in non-athletic and patient populations, Åstrand and Irma Ryhming developed a submaximal cycle test to predict VO2max as a measure of aerobic fitness, published in 1954.[8](https://rplamberts.com/subpage-3-11/) • [9](https://pubmed.ncbi.nlm.nih.gov/11533560/) The nomogram, "A nomogram for calculation of aerobic capacity (physical fitness) from pulse rate during submaximal work," appeared in *Journal of Applied Physiology* volume 7, pages 218–221, and links scales for pulse rate, work load, body weight, and predicted VO2max.[4](https://www.physiolair.com/wp-content/uploads/2022/06/Special_Tests_of_the_Cardiopulmonary.pdf)
The test procedure measures steady-state heart rate during the last minute of six minutes of submaximal cycling at a constant work rate and a pedal frequency of 50 rpm, aiming for a [rating of perceived exertion](https://www.edgepedia.org/rating-of-perceived-exertion) of about 13 on the Borg scale; VO2max is then read from the nomogram using workload, steady-state heart rate, and sex, with a further age correction.[10](https://pmc.ncbi.nlm.nih.gov/articles/PMC11129997/) Irma Ryhming (later Irma Åstrand, Per-Olof's wife-to-be) co-published the 1954 cycle ergometer study, and the test spread internationally under the name The Åstrand Test.[11](https://www.skbl.se/en/article/IrmaAstrand) Åstrand's 1960 monograph on predicting maximal oxygen uptake from heart rate and work load on the bicycle ergometer appeared in *Acta Physiologica Scandinavica* volume 49, supplement 169.[12](https://paperzz.com/doc/8784424/work-tests-with-the-bicycle-ergometer)
The test moved ergometry out of the laboratory and hospital into schools, clubs, and enterprises, following a GCI education program that taught gymnastics teachers and athletics leaders to run simple tests of heart function and physical fitness with the bicycle ergometer.[12](https://paperzz.com/doc/8784424/work-tests-with-the-bicycle-ergometer) A related submaximal test developed in the 1970s, the PWC 170, predicts VO2max from the workload at a heart rate of 170 beats per minute and remains in regular use alongside the Åstrand test.[8](https://rplamberts.com/subpage-3-11/)
## Textbook and major publications
With Kaare Rodahl, Åstrand wrote *Textbook of Work Physiology: Physiological Bases of Exercise*, first published by McGraw-Hill in 1970, with a second edition in 1977 and a third in 1986.[6](https://openlibrary.org/books/OL4907249M/Textbook_of_work_physiology) The fourth edition (Human Kinetics, 2003, 649 pages, with Hans A. Dahl and S. B. Strömme) combined classical issues in exercise and work physiology with updated research findings.[5](https://books.google.co.uk/books?id=BC9SiAsUPqsC) The book grew out of the Stockholm school's tradition: the project was initiated by Christensen and written by Åstrand with co-authors.[7](https://www.diva-portal.org/smash/get/diva2%3A624136/FULLTEXT02.pdf)
His other work includes a 1959 study in *Journal of Applied Physiology* on maximal heart rate during work in older men, conducted at the Lankenau Medical Center in Philadelphia with nine subjects aged 56 to 68 working to maximal loads on a bicycle ergometer,[13](https://openalex.org/W2256296412) a 1976 review in *Progress in Cardiovascular Diseases* on quantifying exercise capability, which argued that VO2max is under standardized conditions a highly reproducible characteristic of aerobic fitness,[14](https://www.sciencedirect.com/science/article/pii/0033062076900086) and a 1997 33-year follow-up in *Journal of Applied Physiology* with Ulf Bergh and Åsa Kilbom, restudying 27 female and 26 male physical education students first examined in 1949 at mean ages of 22 and 25.[15](https://journals.physiology.org/doi/abs/10.1152/jappl.1997.82.6.1844?iss=6) In the Swedish welfare-state context he also argued for regular exercise for older people as part of rational training for the entire population.[7](https://www.diva-portal.org/smash/get/diva2%3A624136/FULLTEXT02.pdf)
## Recognition
Åstrand received the American College of Sports Medicine Honor Award in 1973, is an honorary Fellow of nine international societies, and was elected a Fellow of the [American Association for the Advancement of Science](https://www.edgepedia.org/american-association-for-the-advancement-of-science) for outstanding career contributions to understanding the physiology of muscular work and its applications.[2](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf) France made him Officer de l'Ordre des Palmes Académiques in 1975.[5](https://books.google.co.uk/books?id=BC9SiAsUPqsC) His English publications number about 200, and he lectured by invitation in approximately 50 countries and 150 different cities outside Sweden.[2](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf)
## Accuracy of the test he created
Later validation work quantifies how well the nomogram performs. A 2001 study of 25 subjects (mean age 28.6, range 22–50) completing 52 treadmill trials found that linear extrapolation of the heart rate/oxygen uptake plot was preferable to the nomogram, with an intraclass correlation coefficient of 0.9433 against 0.9443 for directly observed VO2max and a bias of −1.1 ml·min⁻¹·kg⁻¹, a 2.19 percent underestimate.[9](https://pubmed.ncbi.nlm.nih.gov/11533560/) In an elderly population, the Å-test underestimated VO2max in both women and men, with coefficients of variation of 19.8 percent for women and 18.9 percent for men, and the study concluded that the Å-test is not valid for estimating VO2max in the elderly.[16](https://pmc.ncbi.nlm.nih.gov/articles/PMC6989574/) Predicted VO2max from cycle ergometry may also underestimate treadmill VO2max by up to 15 percent in walkers and runners.[4](https://www.physiolair.com/wp-content/uploads/2022/06/Special_Tests_of_the_Cardiopulmonary.pdf) These results frame the nomogram as a practical screening estimate whose precision depends on population and mode of exercise, the same trade-off between feasibility and accuracy that motivated its creation.
## References
1. [Per-Olof Åstrand, Nationalencyklopedin](https://www.ne.se/uppslagsverk/encyklopedi/l%C3%A5ng/per-olof-%C3%A5strand)
2. [Introduction: A View of the Past (McArdle, Katch & Katch), Sportscience](https://www.sportsci.org/2014/McArdleKatchKatchIntroHistory.pdf)
3. [Åstrand, P.-O. (1991). Influence of Scandinavian scientists in exercise physiology. Scandinavian Journal of Medicine & Science in Sports, 1: 3–9](https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0838.1991.tb00264.x)
4. [Special Tests for Cardiopulmonary, Vascular, and Gastrointestinal Systems (nomogram figure and notes)](https://www.physiolair.com/wp-content/uploads/2022/06/Special_Tests_of_the_Cardiopulmonary.pdf)
5. [Textbook of Work Physiology: Physiological Bases of Exercise, 4th ed., Google Books](https://books.google.co.uk/books?id=BC9SiAsUPqsC)
6. [Textbook of work physiology, Open Library](https://openlibrary.org/books/OL4907249M/Textbook_of_work_physiology)
7. [Svensson, D. (2013). How Much Sport is there in Sport Physiology? Practice and Ideas in the Stockholm School of Physiology at GCI, 1941–1969](https://www.diva-portal.org/smash/get/diva2%3A624136/FULLTEXT02.pdf)
8. [Background of the LSCT, Prof Rob Lamberts](https://rplamberts.com/subpage-3-11/)
9. [Macsween, A. (2001). The reliability and validity of the Astrand nomogram and linear extrapolation for deriving VO2max from submaximal exercise data. J Sports Med Phys Fitness 41(3):312–7](https://pubmed.ncbi.nlm.nih.gov/11533560/)
10. [Reference values for estimated VO2max by two submaximal cycle tests: the Åstrand-test and the Ekblom-Bak test, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC11129997/)
11. [Irma Linnéa Åstrand, Svenskt kvinnobiografiskt lexikon](https://www.skbl.se/en/article/IrmaAstrand)
12. [Work tests with the bicycle ergometer, by Per-Olof Åstrand (1964 text)](https://paperzz.com/doc/8784424/work-tests-with-the-bicycle-ergometer)
13. [Maximal heart rate during work in older men, J Appl Physiol 14(4):562 (1959), OpenAlex](https://openalex.org/W2256296412)
14. [Åstrand, P.-O. (1976). Quantification of exercise capability and evaluation of physical capacity in man. Progress in Cardiovascular Diseases 19(1):51–67](https://www.sciencedirect.com/science/article/pii/0033062076900086)
15. [Åstrand, Bergh & Kilbom (1997). A 33-yr follow-up of peak oxygen uptake and related variables of former physical education students. J Appl Physiol 82(6):1844–1852](https://journals.physiology.org/doi/abs/10.1152/jappl.1997.82.6.1844?iss=6)
16. [Criterion validity of the Ekblom-Bak and the Åstrand submaximal test in an elderly population, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC6989574/)
---
*Topic: Encyclopedia › Life and health › Human health and medicine › Nutrition and personal wellbeing › Physical fitness and exercise › Exercise physiology and fitness testing › Exercise physiologists and fitness scientists*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 11, 2026; Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license