{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T03:09:27Z","timestamp":1775790567299,"version":"3.50.1"},"reference-count":50,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2023,10,26]],"date-time":"2023-10-26T00:00:00Z","timestamp":1698278400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council","doi-asserted-by":"publisher","award":["RGPIN-2018-06424"],"award-info":[{"award-number":["RGPIN-2018-06424"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Faculty of Kinesiology (University of Calgary)","award":["RGPIN-2018-06424"],"award-info":[{"award-number":["RGPIN-2018-06424"]}]},{"name":"NSERC CREATE We-TRAC","award":["RGPIN-2018-06424"],"award-info":[{"award-number":["RGPIN-2018-06424"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We sought to determine the utility of Stryd, a commercially available inertial measurement unit, to quantify running intensity and aerobic fitness. Fifteen (eight male, seven female) runners (age = 30.2 [4.3] years; V\u00b7O2max = 54.5 [6.5] ml\u00b7kg\u22121\u00b7min\u22121) performed moderate- and heavy-intensity step transitions, an incremental exercise test, and constant-speed running trials to establish the maximal lactate steady state (MLSS). Stryd running power stability, sensitivity, and reliability were evaluated near the MLSS. Stryd running power was also compared to running speed, V\u00b7O2, and metabolic power measures to estimate running mechanical efficiency (EFF) and to determine the efficacy of using Stryd to delineate exercise intensities, quantify aerobic fitness, and estimate running economy (RE). Stryd running power was strongly associated with V\u00b7O2 (R2 = 0.84; p &lt; 0.001) and running speed at the MLSS (R2 = 0.91; p &lt; 0.001). Stryd running power measures were strongly correlated with RE at the MLSS when combined with metabolic data (R2 = 0.79; p &lt; 0.001) but not in isolation from the metabolic data (R2 = 0.08; p = 0.313). Measures of running EFF near the MLSS were not different across intensities (~21%; p &gt; 0.05). In conclusion, although Stryd could not quantify RE in isolation, it provided a stable, sensitive, and reliable metric that can estimate aerobic fitness, delineate exercise intensities, and approximate the metabolic requirements of running near the MLSS.<\/jats:p>","DOI":"10.3390\/s23218729","type":"journal-article","created":{"date-parts":[[2023,10,26]],"date-time":"2023-10-26T07:22:15Z","timestamp":1698304935000},"page":"8729","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Is Running Power a Useful Metric? Quantifying Training Intensity and Aerobic Fitness Using Stryd Running Power Near the Maximal Lactate Steady State"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7290-1559","authenticated-orcid":false,"given":"Cody R.","family":"van Rassel","sequence":"first","affiliation":[{"name":"Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Oluwatimilehin O.","family":"Ajayi","sequence":"additional","affiliation":[{"name":"Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kate M.","family":"Sales","sequence":"additional","affiliation":[{"name":"Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"James K.","family":"Griffiths","sequence":"additional","affiliation":[{"name":"Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9343-0306","authenticated-orcid":false,"given":"Jared R.","family":"Fletcher","sequence":"additional","affiliation":[{"name":"Department of Health and Physical Education, Mount Royal University, Calgary, AB T3E 6K6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"W. Brent","family":"Edwards","sequence":"additional","affiliation":[{"name":"Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin J.","family":"MacInnis","sequence":"additional","affiliation":[{"name":"Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,10,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/0021-9290(83)90035-0","article-title":"A model for the calculation of mechanical power during distance running","volume":"16","author":"Williams","year":"1983","journal-title":"J. Biomech."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"457","DOI":"10.1016\/S0021-9290(99)00187-6","article-title":"Mechanical power in running: A comparison of different approaches","volume":"33","author":"Arampatzis","year":"2000","journal-title":"J. Biomech."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1242\/jeb.198.2.379","article-title":"External, internal and total work in human locomotion","volume":"198","author":"Willems","year":"1995","journal-title":"J. Exp. Biol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s00421-009-1008-7","article-title":"Efficiency in cycling: A review","volume":"106","author":"Ettema","year":"2009","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"882","DOI":"10.1139\/apnm-2017-0826","article-title":"Using ramp-incremental V\u00b7O2 responses for constant-intensity exercise selection","volume":"43","author":"Keir","year":"2018","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2507","DOI":"10.1007\/s00421-020-04474-7","article-title":"Biomechanical and metabolic aspects of backward (and forward) running on uphill gradients: Another clue towards an almost inelastic rebound","volume":"120","author":"Rasica","year":"2020","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2495","DOI":"10.1007\/s00421-020-04472-9","article-title":"The influence of Achilles tendon mechanical behaviour on \u201capparent\u201d efficiency during running at different speeds","volume":"120","author":"Monte","year":"2020","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2071","DOI":"10.1242\/jeb.201.13.2071","article-title":"Mechanics and energetics of human locomotion on sand","volume":"201","author":"Lejeune","year":"1998","journal-title":"J. Exp. Biol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1249\/MSS.0000000000000763","article-title":"Comparison of the YMCA and a custom submaximal exercise test for determining V\u00b7O2max","volume":"48","author":"Jamnick","year":"2016","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1426","DOI":"10.1080\/02640414.2016.1215504","article-title":"Knowledge is power: Issues of measuring training and performance in cycling","volume":"35","author":"Passfield","year":"2017","journal-title":"J. Sports Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1080\/17461391.2020.1748117","article-title":"Are we ready to measure running power? Repeatability and concurrent validity of five commercial technologies","volume":"21","year":"2021","journal-title":"Eur. J. Sport. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Jaen-Carrillo, D., Roche-Seruendo, L.E., Carton-Llorente, A., Ramirez-Campillo, R., and Garcia-Pinillos, F. (2020). Mechanical power in endurance running: A scoping review on sensors for power output estimation during running. Sensors, 20.","DOI":"10.3390\/s20226482"},{"key":"ref_13","unstructured":"Stryd, T. (2022, January 11). How to Lead the Pack: Running Power Meters & Quality Data. Available online: https:\/\/blog.stryd.com\/2017\/12\/07\/how-to-lead-the-pack-running-power-meters-quality-data\/."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1519\/JSC.0000000000002595","article-title":"Absolute reliability and concurrent validity of the Stryd system for the assessment of running stride kinematics at different velocities","volume":"35","year":"2021","journal-title":"J. Strength. Cond. Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"498","DOI":"10.1055\/a-0875-4068","article-title":"Reliability of trail walking and running tasks using the Stryd power meter","volume":"40","author":"Navalta","year":"2019","journal-title":"Int. J. Sports Med."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Cart\u00f3n-Llorente, A., Roche-Seruendo, L.E., Mainer-Pardos, E., Nobari, H., Rubio-Peirot\u00e9n, A., Ja\u00e9n-Carrillo, D., and Garc\u00eda-Pinillos, F. (2022). Acute effects of a 60-min time trial on power-related parameters in trained endurance runners. BMC Sports Sci. Med. Rehabil., 14.","DOI":"10.1186\/s13102-022-00538-7"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"238","DOI":"10.1016\/j.gaitpost.2018.11.037","article-title":"Prediction of power output at different running velocities through the two-point method with the Stryd\u2122 power meter","volume":"68","year":"2019","journal-title":"Gait Posture"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1555","DOI":"10.1080\/17461391.2021.1966104","article-title":"Running power: Lab based vs. portable devices measurements and its relationship with aerobic power","volume":"22","author":"Taboga","year":"2022","journal-title":"Eur. J. Sport. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1123\/ijspp.2021-0451","article-title":"Defining training and performance caliber: A participant classification framework","volume":"17","author":"McKay","year":"2022","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"ref_20","first-page":"534","article-title":"A \u201cStep-Ramp-Step\u201d protocol to identify running speed and power associated with the maximal metabolic steady state","volume":"55","author":"Ajayi","year":"2022","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2011","DOI":"10.1249\/MSS.0000000000002343","article-title":"A \u201cStep-Ramp-Step\u201d protocol to identify the maximal metabolic steady state","volume":"52","author":"Iannetta","year":"2020","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1097\/00005768-199602000-00013","article-title":"Determination of maximal lactate steady state response in selected sports events","volume":"28","author":"Beneke","year":"1996","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1080\/02640419608727717","article-title":"A 1% treadmill grade most accurately reflects the energetic cost of outdoor running","volume":"14","author":"Jones","year":"1996","journal-title":"J. Sports Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2020","DOI":"10.1152\/jappl.1986.60.6.2020","article-title":"A new method for detecting anaerobic threshold by gas exchange","volume":"60","author":"Beaver","year":"1986","journal-title":"J. Appl. Physiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1016\/0034-5687(89)90076-5","article-title":"Ventilatory control of the \u2018isocapnic buffering\u2019 region in rapidly-incremental exercise","volume":"76","author":"Whipp","year":"1989","journal-title":"Respir. Physiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1249\/00005768-198205000-00012","article-title":"Psychophysical bases of perceived exertion","volume":"14","author":"Borg","year":"1982","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"407","DOI":"10.2165\/00007256-200333060-00003","article-title":"The concept of maximal lactate steady state: A bridge between biochemistry, physiology and sport science","volume":"33","author":"Billat","year":"2003","journal-title":"Sports Med."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3133","DOI":"10.1007\/s00421-021-04780-8","article-title":"Steady-state V\u00b7O2 above MLSS: Evidence that critical speed better represents maximal metabolic steady state in well-trained runners","volume":"121","author":"Nixon","year":"2021","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1152\/japplphysiol.00507.2015","article-title":"Constructing quasi-linear V\u00b7O2 responses from nonlinear parameters","volume":"120","author":"Wilcox","year":"2016","journal-title":"J. Appl. Physiol."},{"key":"ref_30","first-page":"23","article-title":"Table of nonprotein respiratory quotient: An update","volume":"16","author":"Peronnet","year":"1991","journal-title":"Can. J. Sport. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.jcm.2016.02.012","article-title":"A guideline of selecting and reporting intraclass correlation coefficients for reliability research","volume":"15","author":"Koo","year":"2016","journal-title":"J. Chiropr. Med."},{"key":"ref_32","unstructured":"Hoffman, L. (2015). Longitudinal Analysis: Modeling within-Person Fluctuation and Change, Routledge."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1055\/a-0946-2159","article-title":"How does power during running change when measured at different time intervals?","volume":"40","year":"2019","journal-title":"Int. J. Sports Med."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"112972","DOI":"10.1016\/j.physbeh.2020.112972","article-title":"Running power meters and theoretical models based on laws of physics: Effects of environments and running conditions","volume":"223","author":"Pallares","year":"2020","journal-title":"Physiol. Behav."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2481","DOI":"10.1111\/sms.13280","article-title":"Metabolic and performance-related consequences of exercising at and slightly above MLSS","volume":"28","author":"Iannetta","year":"2018","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"466","DOI":"10.1249\/MSS.0000000000002147","article-title":"A Critical Evaluation of Current Methods for Exercise Prescription in Women and Men","volume":"52","author":"Iannetta","year":"2020","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Baumgartner, T., Held, S., Klatt, S., and Donath, L. (2021). Limitations of foot-worn sensors for assessing running power. Sensors, 21.","DOI":"10.3390\/s21154952"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1111","DOI":"10.1123\/ijspp.2022-0069","article-title":"9\/3-Minute Running Critical Power Test: Mechanical Threshold Location With Respect to Ventilatory Thresholds and Maximum Oxygen Uptake","volume":"17","year":"2022","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Imbach, F., Candau, R., Chailan, R., and Perrey, S. (2020). Validity of the Stryd power meter in measuring running parameters at submaximal speeds. Sports, 8.","DOI":"10.3390\/sports8070103"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"933","DOI":"10.1002\/cphy.c100072","article-title":"Oxygen uptake kinetics","volume":"2","author":"Poole","year":"2012","journal-title":"Compr. Physiol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1097\/00005768-200001000-00012","article-title":"Limiting factors for maximum oxygen uptake and determinants of endurance performance","volume":"32","author":"Bassett","year":"2000","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1304","DOI":"10.1097\/00005768-199808000-00020","article-title":"The validity of the lactate minimum test for determination of the maximal lactate steady state","volume":"30","author":"Jones","year":"1998","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1007\/BF01466278","article-title":"Peak power output predicts maximal oxygen uptake and performance time in trained cyclists","volume":"65","author":"Hawley","year":"1992","journal-title":"Eur. J. Appl. Physiol. Occup. Physiol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1055\/s-2007-971147","article-title":"Critical power is related to cycling time trial performance","volume":"20","author":"Smith","year":"1999","journal-title":"Int. J. Sports Med."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"313","DOI":"10.2165\/00007256-200535040-00003","article-title":"The science of cycling: Factors affecting performance\u2014Part 2","volume":"35","author":"Faria","year":"2005","journal-title":"Sports Med."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"657","DOI":"10.5114\/biolsport.2023.118025","article-title":"Is Stryd critical power a meaningful parameter for runners?","volume":"40","author":"Dearing","year":"2022","journal-title":"Biol. Sport"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Austin, C.L., Hokanson, J.F., McGinnis, P.M., and Patrick, S. (2018). The relationship between running power and running economy in well-trained distance runners. Sports, 6.","DOI":"10.3390\/sports6040142"},{"key":"ref_48","first-page":"11","article-title":"The use of wearable technology to quantify power and muscle load differences during running against varying wind resistances","volume":"10","author":"Bello","year":"2022","journal-title":"Int. J. Kines. Sports Sci."},{"key":"ref_49","unstructured":"Stryd, T. (2023, March 29). New Power-Based Metric Reveals the Wind So You Can Benefit from Its Effects. Available online: https:\/\/blog.stryd.com\/2019\/08\/16\/introducing-air-power\/."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"S2161","DOI":"10.1123\/IJSPP.2017-0208","article-title":"Monitoring Athlete Training Loads: Consensus Statement","volume":"12","author":"Bourdon","year":"2017","journal-title":"Int. J. Sports Physiol. Perform."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/21\/8729\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:12:02Z","timestamp":1760130722000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/21\/8729"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,10,26]]},"references-count":50,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2023,11]]}},"alternative-id":["s23218729"],"URL":"https:\/\/doi.org\/10.3390\/s23218729","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,10,26]]}}}