{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T10:59:57Z","timestamp":1766401197009,"version":"3.43.0"},"reference-count":41,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"8","content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2023,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:p>Mendonca, GV, Fitas, A, Santos, P, Gomes, M, and Pezarat-Correia, P. Predictive equations to estimate relative load based on movement velocity in males and females: accuracy of estimation for the Smith machine concentric back squat. <jats:italic toggle=\"yes\">J Strength Cond Res<\/jats:italic> 37(8): 1559\u20131565, 2023\u2014We sought to determine the validity of using the Smith machine bar velocity to estimate relative load during the concentric back squat performed by adult male and female subjects. Thirty-two subjects (16 men: 23.3 \u00b1 3.8 and 16 women: 26.1 \u00b1 2.7 years) were included. The load-velocity relationship was extracted for all subjects individually. Mean concentric velocity (MCV), combined with sex, was used to develop equations predictive of relative load (% one repetition maximum [1RM]). Prediction accuracy was determined with the mean absolute percent error and Bland-Altman plots. Relative strength was similar between the sexes. However, male subjects exhibited faster concentric MCV at 1RM (<jats:italic toggle=\"yes\">p<\/jats:italic> &lt; 0.05). Mean concentric velocity and the sex-by-MCV interaction were both significant predictors of %1RM (<jats:italic toggle=\"yes\">p<\/jats:italic> &lt; 0.0001), explaining 89% of its variance. The absolute error was similar between the sexes (men: 9.4 \u00b1 10.0; women: 8.4 \u00b1 10.5, <jats:italic toggle=\"yes\">p<\/jats:italic> &gt; 0.05). The mean difference between actual and predicted %1RM in Bland-Altman analysis was nearly zero in both sexes and showed no heteroscedasticity. The limits of agreement in both men and women were of approximately \u00b115%. Taken together, it can be concluded that sex should be taken into consideration when aiming at accurate prescription of relative load based on movement velocity. Moreover, predicting relative load from MCV and sex provides an error of approximately 10% in assessments of relative load in groups of persons. Finally, when used for individual estimations, these equations may implicate a considerable deviation from the actual relative load, and this may limit their applicability to training conditions in which extreme accuracy is required (i.e., more advanced lifters and athletes).<\/jats:p>","DOI":"10.1519\/jsc.0000000000004437","type":"journal-article","created":{"date-parts":[[2023,2,1]],"date-time":"2023-02-01T16:10:39Z","timestamp":1675267839000},"page":"1559-1565","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":11,"title":["Predictive Equations to Estimate Relative Load Based on Movement Velocity in Males and Females: Accuracy of Estimation for the Smith Machine Concentric Back Squat"],"prefix":"10.1519","volume":"37","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8161-8598","authenticated-orcid":false,"given":"Goncalo Vilhena","family":"Mendonca","sequence":"first","affiliation":[{"name":"Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal; and"},{"name":"CIPER, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal"}]},{"given":"Afonso","family":"Fitas","sequence":"additional","affiliation":[{"name":"Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal; and"}]},{"given":"Paulo","family":"Santos","sequence":"additional","affiliation":[{"name":"Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal; and"},{"name":"CIPER, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal"}]},{"given":"Miguel","family":"Gomes","sequence":"additional","affiliation":[{"name":"Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal; and"},{"name":"CIPER, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal"}]},{"given":"Pedro","family":"Pezarat-Correia","sequence":"additional","affiliation":[{"name":"Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal; and"},{"name":"CIPER, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal"}]}],"member":"276","published-online":{"date-parts":[[2023,2,1]]},"reference":[{"key":"R1-20250806","doi-asserted-by":"crossref","first-page":"627","DOI":"10.1016\/j.jclinepi.2014.12.014","article-title":"The number of subjects per variable required in linear regression analyses","volume":"68","author":"Austin","year":"2015","journal-title":"J Clin Epidemiol"},{"key":"R2-20250806","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1177\/1747954117738243","article-title":"Load\u2013velocity profiling in the military press exercise: Effects of gender and training","volume":"13","author":"Balsalobre-Fern\u00e1ndez","year":"2018","journal-title":"Int J Sports Sci Coach"},{"key":"R3-20250806","first-page":"452","article-title":"Analysis of the load-velocity relationship in deadlift exercise","volume":"19","author":"Benavides-Ubric","year":"2020","journal-title":"J Sports Sci Med"},{"key":"R4-20250806","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1177\/096228029900800204","article-title":"Measuring agreement in method comparison studies","volume":"8","author":"Bland","year":"1999","journal-title":"Stat Methods Med Res"},{"key":"R6-20250806","doi-asserted-by":"crossref","first-page":"1099","DOI":"10.1080\/02640414.2015.1090010","article-title":"Movement velocity as a measure of exercise intensity in three lower limb exercises","volume":"34","author":"Conceicao","year":"2016","journal-title":"J Sports Sci"},{"key":"R7-20250806","doi-asserted-by":"crossref","first-page":"145","DOI":"10.2165\/00007256-200737020-00004","article-title":"The adaptations to strength training: Morphological and neurological contributions to increased strength","volume":"37","author":"Folland","year":"2007","journal-title":"Sports Med"},{"key":"R8-20250806","doi-asserted-by":"crossref","first-page":"663","DOI":"10.2165\/00007256-200434100-00004","article-title":"The role of resistance exercise intensity on muscle fibre adaptations","volume":"34","author":"Fry","year":"2004","journal-title":"Sports Med"},{"key":"R9-20250806","doi-asserted-by":"crossref","first-page":"474","DOI":"10.1123\/ijspp.2017-0374","article-title":"Feasibility of the 2-point method for determining the 1-repetition maximum in the bench press exercise","volume":"13","author":"Garcia-Ramos","year":"2018","journal-title":"Int J Sports Physiol Perform"},{"key":"R10-20250806","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1519\/SSC.0000000000000359","article-title":"Two-point method: A quick and fatigue-free procedure for assessment of muscle mechanical capacities and the 1 repetition maximum","volume":"40","author":"Garcia-Ramos","year":"2018","journal-title":"Strength Cond J"},{"key":"R11-20250806","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1080\/14763141.2018.1545044","article-title":"Optimisation of applied loads when using the two-point method for assessing the force-velocity relationship during vertical jumps","volume":"20","author":"Garcia-Ramos","year":"2021","journal-title":"Sports Biomech"},{"key":"R12-20250806","doi-asserted-by":"crossref","first-page":"1273","DOI":"10.1519\/JSC.0000000000001998","article-title":"Mean velocity vs. Mean propulsive velocity vs. peak velocity: Which variable determines bench press relative load with higher reliability?","volume":"32","author":"Garcia-Ramos","year":"2018","journal-title":"J Strength Cond Res"},{"key":"R13-20250806","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1123\/ijspp.2017-0158","article-title":"Differences in the load-velocity profile between 4 bench-press variants","volume":"13","author":"Garcia-Ramos","year":"2018","journal-title":"Int J Sports Physiol Perform"},{"key":"R14-20250806","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1080\/14763141.2019.1597155","article-title":"The load-velocity profiles of three upper-body pushing exercises in men and women","volume":"20","author":"Garcia-Ramos","year":"2021","journal-title":"Sports Biomech"},{"key":"R15-20250806","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1055\/s-0030-1248333","article-title":"Movement velocity as a measure of loading intensity in resistance training","volume":"31","author":"Gonzalez-Badillo","year":"2010","journal-title":"Int J Sports Med"},{"key":"R16-20250806","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1519\/JSC.0000000000001517","article-title":"RPE and velocity relationships for the back squat, bench press, and deadlift in powerlifters","volume":"31","author":"Helms","year":"2017","journal-title":"J Strength Cond Res"},{"key":"R17-20250806","doi-asserted-by":"crossref","first-page":"235","DOI":"10.5114\/biolsport.2020.98453","article-title":"A comprehensive analysis of the velocity-based method in the shoulder press exercise: Stability of the load-velocity relationship and sticking region parameters","volume":"38","author":"Hernandez-Belmonte","year":"2021","journal-title":"Biol Sport"},{"key":"R18-20250806","doi-asserted-by":"crossref","first-page":"2562","DOI":"10.1080\/02640414.2020.1794235","article-title":"Load-velocity relationship 1RM predictions: A comparison of Smith machine and free-weight exercise","volume":"38","author":"Hughes","year":"2020","journal-title":"J Sports Sci"},{"key":"R19-20250806","doi-asserted-by":"crossref","first-page":"718","DOI":"10.1055\/s-2005-872825","article-title":"Effect of loading on unintentional lifting velocity declines during single sets of repetitions to failure during upper and lower extremity muscle actions","volume":"27","author":"Izquierdo","year":"2006","journal-title":"Int J Sports Med"},{"key":"R20-20250806","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1519\/JSC.0b013e3181b62c5f","article-title":"Using the load-velocity relationship for 1RM prediction","volume":"25","author":"Jidovtseff","year":"2011","journal-title":"J Strength Cond Res"},{"key":"R21-20250806","doi-asserted-by":"crossref","first-page":"997","DOI":"10.1002\/j.2040-4603.2012.tb00427.x","article-title":"Skeletal muscle fatigue","volume":"2","author":"Kent-Braun","year":"2012","journal-title":"Compr Physiol"},{"key":"R22-20250806","doi-asserted-by":"crossref","first-page":"1813","DOI":"10.1152\/japplphysiol.00091.2002","article-title":"Human skeletal muscle responses vary with age and gender during fatigue due to incremental isometric exercise","volume":"93","author":"Kent-Braun","year":"1985","journal-title":"J Appl Physiol"},{"key":"R23-20250806","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1249\/01.MSS.0000121945.36635.61","article-title":"Fundamentals of resistance training: Progression and exercise prescription","volume":"36","author":"Kraemer","year":"2004","journal-title":"Med Sci Sports Exerc"},{"key":"R25-20250806","doi-asserted-by":"crossref","first-page":"111391","DOI":"10.1016\/j.exger.2021.111391","article-title":"Load-velocity relationship in the horizontal leg-press exercise in older women and men","volume":"151","author":"Marques","year":"2021","journal-title":"Exp Gerontol"},{"key":"R26-20250806","doi-asserted-by":"crossref","first-page":"1088","DOI":"10.1080\/02640414.2018.1544187","article-title":"Velocity- and power-load relationships in the half, parallel and full back squat","volume":"37","author":"Martinez-Cava","year":"2019","journal-title":"J Sports Sci"},{"key":"R27-20250806","doi-asserted-by":"crossref","first-page":"1249","DOI":"10.1123\/ijspp.2016-0657","article-title":"Load-, force-, and power-velocity relationships in the prone pull-up exercise","volume":"12","author":"Mu\u00f1oz-L\u00f3pez","year":"2017","journal-title":"Int J Sports Physiol Perform"},{"key":"R28-20250806","first-page":"1","article-title":"Exercise and sport science failing by design in understanding female athletes","volume":"25","author":"Nimphius","year":"2019","journal-title":"Int J Sports Physiol Perform"},{"key":"R29-20250806","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1080\/02640414.2014.889844","article-title":"Imposing a pause between the eccentric and concentric phases increases the reliability of isoinertial strength assessments","volume":"32","author":"Pallares","year":"2014","journal-title":"J Sports Sci"},{"key":"R30-20250806","doi-asserted-by":"crossref","first-page":"1047","DOI":"10.1055\/a-1171-2287","article-title":"Validity of using velocity to estimate intensity in resistance exercises in men and women","volume":"41","author":"Pareja-Blanco","year":"2020","journal-title":"Int J Sports Med"},{"key":"R31-20250806","doi-asserted-by":"crossref","first-page":"1024","DOI":"10.1519\/JSC.0000000000002072","article-title":"Load-velocity relationship in variations of the half-squat exercise: Influence of execution technique","volume":"34","author":"Perez-Castilla","year":"2020","journal-title":"J Strength Cond Res"},{"key":"R32-20250806","doi-asserted-by":"crossref","first-page":"1258","DOI":"10.1519\/JSC.0000000000003118","article-title":"Reliability and concurrent validity of seven commercially available devices for the assessment of movement velocity at different intensities during the bench press","volume":"33","author":"Perez-Castilla","year":"2019","journal-title":"J Strength Cond Res"},{"key":"R33-20250806","doi-asserted-by":"crossref","first-page":"544","DOI":"10.1016\/j.jshs.2021.11.003","article-title":"Feasibility of the 2-point method to determine the load-velocity relationship variables during the countermovement jump exercise","volume":"12","author":"Perez-Castilla","year":"2023","journal-title":"J Sport Health Sci"},{"key":"R34-20250806","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1007\/s00421-002-0739-5","article-title":"Gender-specific knee extensor torque, flexor torque, and muscle fatigue responses during maximal effort contractions","volume":"89","author":"Pincivero","year":"2003","journal-title":"Eur J Appl Physiol"},{"key":"R35-20250806","doi-asserted-by":"crossref","first-page":"157","DOI":"10.5604\/20831862.1099047","article-title":"The relationship between the number of repetitions performed at given intensities is different in endurance and strength trained athletes","volume":"31","author":"Richens","year":"2014","journal-title":"Biol Sport"},{"key":"R36-20250806","first-page":"209","article-title":"Velocity- and power-load relationships of the bench pull vs. bench press exercises","volume":"35","author":"Sanchez-Medina","year":"2014","journal-title":"Int J Sports Med"},{"key":"R37-20250806","doi-asserted-by":"crossref","first-page":"E80","DOI":"10.1055\/s-0043-102933","volume":"1","author":"Sanchez-Medina","year":"2017","journal-title":"Sports Med Int Open"},{"key":"R38-20250806","doi-asserted-by":"crossref","first-page":"1378","DOI":"10.1123\/ijspp.2016-0791","article-title":"Movement velocity as indicator of relative intensity and level of effort attained during the set in pull-up exercise","volume":"12","author":"Sanchez-Moreno","year":"2017","journal-title":"Int J Sports Physiol Perform"},{"key":"R39-20250806","doi-asserted-by":"crossref","first-page":"S61","DOI":"10.1249\/MSS.0b013e3182399e0f","article-title":"Statistical considerations in the analysis of accelerometry-based activity monitor data","volume":"44","author":"Staudenmayer","year":"2012","journal-title":"Med Sci Sports Exerc"},{"key":"R40-20250806","doi-asserted-by":"crossref","first-page":"1419","DOI":"10.1007\/s40279-016-0486-0","article-title":"The importance of muscular strength in athletic performance","volume":"46","author":"Suchomel","year":"2016","journal-title":"Sports Med"},{"key":"R41-20250806","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1080\/14763141.2018.1433872","article-title":"The load-velocity profile differs more between men and women than between individuals with different strength levels","volume":"18","author":"Torrejon","year":"2019","journal-title":"Sports Biomech"},{"key":"R42-20250806","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1519\/SSC.0000000000000560","article-title":"Velocity-based training: From theory to application","volume":"42","author":"Weakley","year":"2021","journal-title":"Strength Cond J"},{"key":"R43-20250806","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1007\/s40279-020-01382-w","article-title":"The validity and reliability of commercially available resistance training monitoring devices: A systematic review","volume":"51","author":"Weakley","year":"2021","journal-title":"Sports Med"}],"container-title":["Journal of Strength &amp; Conditioning Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.lww.com\/10.1519\/JSC.0000000000004437","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,6]],"date-time":"2025-08-06T01:03:48Z","timestamp":1754442228000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.lww.com\/10.1519\/JSC.0000000000004437"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,1]]},"references-count":41,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2023]]}},"URL":"https:\/\/doi.org\/10.1519\/jsc.0000000000004437","relation":{},"ISSN":["1064-8011"],"issn-type":[{"type":"print","value":"1064-8011"}],"subject":[],"published":{"date-parts":[[2023,2,1]]}}}