ATLAS study: Design, athletic performance, and sex-specific regression models for muscle strength in the Greek population

Abstract

Purpose: ATLAS is a cross-sectional study aiming to investigate environmental and genetic determinants of athletic performance in healthy Greek competitive athletes (CA). This article presents the study design, investigates the muscle strength performance (MSP) of 289 adult and teenage CA, exercisers, and physically inactive individuals (PI), and proposes predictive models of MSP for adults.

Methods: Muscle maximal, speed, and explosive strength (MMS/MSS/MES) at unilateral maximal concentric flexion and extension contraction (FC/EC) were evaluated using Biodex System 3 PRO™ at 60 °/s, 180 °/s, and 300 °/s, while additional performance markers were assessed through field ergometric testing. Participants were interviewed about their lifestyle, dietary habits, physical activity, injury, and medical history. Body composition was assessed via bioelectrical impedance. gDNA was extracted from biochemical samples and then genotyped. Statistical analysis was conducted using IBM SPSS Statistics v21.0 and R.

Results: Age, fitness, and sex impacted correlations of MSP with body composition and anthropometric measurements (p ​< ​0.05). Among CA, females outperformed males in accuracy (p ​< ​0.001) while, males outperformed females in anaerobic power, MSP, speed, and endurance (p ​< ​0.001). Adult CA outperformed exercisers and PI in MMS, MSS, and MES (p ​< ​0.05). Multiple linear regression models, with predictors age, FFM, body extremity, training load explained the majority of variation in MMS (R²_adj:71.4%-88.9%), MSS (R²_adj:64.8%-78.4 ​%), and MES (R²_adj:52.7%-68.4 ​%) at EC, FC, and their mean (p ​< ​0.001).

Conclusions: Muscle-strengthening strategies should be customized according to individual fitness levels, body composition, and anthropometric measurements. The innovative sex-specific regression models assessing MMS, MSS, and MES at EC and FC provide a framework for personalizing rehabilitation and skill-specific training strategies.

Keywords

Athletic performance / Isokinetic dynamometer / Muscle strength performance / Greek population / Predictive models / Body composition

CRediT authorship contribution statement

Natia A. Pogosova: Writing - review & editing, Writing - original draft, Visualization, Supervision, Methodology, Investigation, Formal analysis, Data curation. Despoina Brekou: Writing - review & editing, Investigation, Data curation. Ioanna E. Gavra: Investigation. Efthymia A. Katsareli: Investigation. Eleni More: Investigation. Panagiotis G. Symianakis: Visualization. Maria Kafyra: Writing – review & editing. Ioanna Panagiota Kalafati: Writing – review & editing. Giannis Arnaoutis: Methodology. George V. Dedoussis: Supervision, Resources, Project administration, Methodology, Funding acquisition, Conceptualization.

Ethical approval statement

The study was conducted following the guidelines of the Declaration of Helsinki and received approval from the Research Ethics Committee of Harokopio University of Athens (Protocol numbers: 42/28-05-2014, Γ-3347/20-07-2021, Γ-1173/15-03-2022). All participants were thor-oughly informed about the study procedures orally and provided their informed consent by signing the consent form before participating.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The ATLAS study was conducted at Harokopio University of Athens. The authors extend their gratitude to Evdokia K. Mitsou, PhD(c), for her support and assistance in reproducing the questionnaires. Special thanks to Associate Professor Tzortzis Nomikos, Theodoros P. Angelopoulos, MD, Giannis Kotsis, Sports Scientist, and Mr. Christos Amourgis for facilitating contact with volunteers. We also thank Napoleon Ana-gnostou, MD, the teams' doctor, and the coaches—George Saranteas, Kostas Antonopoulos, Stavros Raptis, Philippos Kantarakis, and Dimitrios Dimitriadis—for enabling us to conduct measurements on their teams' athletes. Last but not least, we sincerely thank all volunteers for their indispensable collaboration.

Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.org/10.1016/j.smhs.2024.11.002.

References

[1] Clemente FM, Clark C, Castillo D, et al. Variations of training load, monotony, and strain and dose-response relationships with maximal aerobic speed, maximal oxygen uptake, and isokinetic strength in professional soccer players. PLoS One. 2019; 14(12):e0225522. https://doi.org/10.1371/journal.pone.0225522.

[2] Li C, Wang JCK, Pyun DY. Talent development environmental factors in sport: a review and taxonomic classification. Quest. 2014; 66(4):433-447. https://doi.org/10.1080/00336297.2014.944715.

[3] Kim DS, Wheeler MT, Ashley EA. The genetics of human performance. Nat Rev Genet. 2022; 23(1):40-54. https://doi.org/10.1038/s41576-021-00400-5.

[4] Frontera WR, Ochala J. Skeletal muscle: a brief review of structure and function. Calcif Tissue Int. 2015; 96(3):183-195. https://doi.org/10.1007/s00223-014-9915-y.

[5] Stanelle ST, Crouse SF, Heimdal TR, Riechman SE, Remy AL, Lambert BS. Predicting muscular strength using demographics, skeletal dimensions, and body composition measures. Sports Med Health Sci. 2021; 3(1):34-39. https://doi.org/10.1016/j.smhs.2021.02.001.

[6] Suchomel TJ, Nimphius S, Stone MH. The importance of muscular strength in athletic performance. Sports Med. 2016; 46(10):1419-1449. https://doi.org/10.1007/s40279-016-0486-0.

[7] Suchomel TJ, Nimphius S, Bellon CR, Stone MH. The importance of muscular strength: training considerations. Sports Med. 2018; 48(4):765-785. https://doi.org/10.1007/s40279-018-0862-z.

[8] Vandewoude MF, Alish CJ, Sauer AC, Hegazi RA. Malnutrition-sarcopenia syndrome: is this the future of nutrition screening and assessment for older adults? J Aging Res. 2012; 2012:651570. https://doi.org/10.1155/2012/651570.

[9] Braddom RL ed. Physical Medicine and Rehabilitation. fourth ed. Philadelphia: PA: Elsevier; 2011. https://bit.ly/3yiz3Sw.Accessed June 26, 2024.

[10] Leite MM, de Sousa Neto IV, Dutra MT, et al. Predictive models of muscle strength in older people with type 2 diabetes mellitus. Clin Interv Aging. 2023; 18:1535-1546. https://doi.org/10.2147/CIA.S414620.

[11] Ahsan M, Ahmed MD, Azeem K. Role of predictive modeling and personalized modeling in the enhancement of athletic performance. Saudi J Sports Med. 2023; 23(1):7-9. https://doi.org/10.4103/sjsm.sjsm_7_23.

[12] Neder JA, Nery LE, Shinzato GT, Andrade MS, Peres C, Silva AC. Reference values for concentric knee isokinetic strength and power in nonathletic men and women from 20 to 80 years old. J Orthop Sports Phys Ther. 1999; 29(2):116-126. https://doi.org/10.2519/jospt.1999.29.2.116.

[13] Harbo T, Brincks J, Andersen H. Maximal isokinetic and isometric muscle strength of major muscle groups related to age, body mass, height, and sex in 178 healthy subjects. Eur J Appl Physiol. 2012; 112(1):267-275. https://doi.org/10.1007/s00421-011-1975-3.

[14] Hammami R, Chaouachi A, Makhlouf I, Granacher U, Behm DG. Associations between balance and muscle strength, power performance in male youth athletes of different maturity status. Pediatr Exerc Sci. 2016; 28(4):521-534. https://doi.org/10.1123/pes.2015-0231.

[15] Silva AM, Shen W, Heo M, et al. Ethnicity-related skeletal muscle differences across the lifespan. Am J Hum Biol. 2010; 22(1):76-82. https://doi.org/10.1002/ajhb.20956.

[16] Handelsman DJ. Sex differences in athletic performance emerge coinciding with the onset of male puberty. Clin Endocrinol. 2017; 87(1):68-72. https://doi.org/10.1111/cen.13350.

[17] Stark T, Walker B, Phillips JK, Fejer R, Beck R. Hand-held dynamometry correlation with the gold standard isokinetic dynamometry: a systematic review. Pharm Manag PM R. 2011; 3(5):472-479. https://doi.org/10.1016/j.pmrj.2010.10.025.

[18] Lockie RG, Ruvalcaba TR, Stierli M, Dulla JM, Dawes JJ, Orr RM. Waist circumference and waist-to-hip ratio in law enforcement agency recruits: relationship to performance in physical fitness tests. J Strength Condit Res. 2020; 34(6):1666-1675. https://doi.org/10.1519/JSC.0000000000002825.

[19] Lukaski H, Raymond-Pope CJ. New frontiers of body composition in sport. Int J Sports Med. 2021; 42(7):588-601. https://doi.org/10.1055/a-1373-5881.

[20] Toth AJ, Ramsbottom N, Constantin C, Milliet A, Campbell MJ. The effect of expertise, training and neurostimulation on sensory-motor skill in esports. Comput Hum Behav. 2021; 121:106782. https://doi.org/10.1016/j.chb.2021.106782.

[21] McKinney J, Velghe J, Fee J, Isserow S, Drezner JA. Defining athletes and exercisers. Am J Cardiol. 2019; 123(3):532-535. https://doi.org/10.1016/j.amjcard.2018.11.001.

[22] Park J. Using physical activity levels to estimate energy requirements of female athletes. J Exerc Nutrition Biochem. 2019; 23(4):1-5. https://doi.org/10.20463/jenb.2019.0024.

[23] Kavouras SA, Maraki MI, Kollia M, Gioxari A, Jansen LT, Sidossis LS. Development, reliability and validity of a physical activity questionnaire for estimating energy expenditure in Greek adults. Sci Sports. 2016; 31(3):e47-e53. https://doi.org/10.1016/j.scispo.2016.01.007.

[24] Magkos F, Manios Y, Babaroutsi E, Sidossis LS. Development and validation of a food frequency questionnaire for assessing dietary calcium intake in the general population. Osteoporosis Int. 2006; 17(2):304-312. https://doi.org/10.1007/s00198-004-1679-1.

[25] Ministry of Health and Welfare. Dietary guidelines for adults in Greece. Arch Hellenic Med. 1999; 16:516-524. https://tinyurl.com/3e97m3ke. Accessed September 29, 2023.

[26] Rupasinghe W, Wickramaratne MN. A comprehensive review on dietary assessment methods in epidemiological studies. Publ Health Nutr. 2020; 3(1):204-211. https://bit.ly/3LONXTn. Accessed July 29, 2024.

[27] Biodex Medical Systems Inc. Shirley, NY: Biodex Medical Systems. Inc.; 2015. Published online https://bit.ly/4bXG09i. Accessed February 10, 2023.

[28] Virgile A, Bishop C. A narrative review of limb dominance: task specificity and the importance of fitness testing. J Strength Condit Res. 2021; 35(3):846-858. https://doi.org/10.1519/JSC.0000000000003851.

[29] van Melick N, Meddeler BM, Hoogeboom TJ, Nijhuis-van der Sanden MWG, van Cingel REH. How to determine leg dominance: the agreement between self-reported and observed performance in healthy adults. PLoS One. 2017; 12(12):e0189876. https://doi.org/10.1371/journal.pone.0189876.

[30] Schindler IFSR, Pontes SS, Bertoni MBM, et al. A systematic review of isokinetic muscle strength in a healthy population with special reference to age and gender. Sport Health. 2023; 15(3):328-332. https://doi.org/10.1177/19417381221146258.

[31] Maffiuletti NA, Bizzini M, Desbrosses K, Babault N, Munzinger U. Reliability of knee extension and flexion measurements using the con-trex isokinetic dynamometer. Clin Physiol Funct Imag. 2007; 27(6):346-353. https://doi.org/10.1111/j.1475-097X.2007.00758.x.

[32] Isohelix. Buccal-prep Plus DNA isolation kit. Harrietsham,Kent: Isohelix; 2023. Published online https://isohelix.com/products/bpp/.Accessed June 20,2024.

[33] ThermoFisher Scientific. Waltham, iPrep pure link gDNA blood kit. MA: ThermoFisher scientific. Published online https://bit.ly/4bXFEiY; 2024. Accessed June 20, 2024.

[34] Illumina. Infinium global screening array-24 kit. Published online https://bit.ly/3A20lwU; 2024. Accessed June 20, 2024.

[35] ThermoFisher Scientific. Axiom precision medicine diversity array Plus kit, 96-format. Published online https://bit.ly/3Yi4oPK; 2024. Accessed June 20, 2024.

[36] Illumina. Infinium CoreExome-24 v1.4 BeadChip. Published online https://bit.ly/3WqhB6j; 2024. Accessed June 20, 2024.

[37] Knechtle B, Knechtle P, Schulze I, Kohler G. Upper arm circumference is associated with race performance in ultra-endurance runners. Br J Sports Med. 2008; 42(4): 295-299. https://doi.org/10.1136/bjsm.2007.038570.

[38] Maillard F, Pereira B, Boisseau N. Effect of high-intensity interval training on total, abdominal and visceral Fat Mass: a Meta-Analysis. Sports Med. 2018; 48(2):269-288. https://doi.org/10.1007/s40279-017-0807-y.

[39] Harrell Jr F.Hmisc: harrell miscellaneous. Published online https://bit.ly/3WmCZJJ; 2023. Accessed June 20, 2024.

[40] R Core Team. A Language andEnvironment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing; 2021. Published online https://bit.ly/47hJEtY. Accessed September 8, 2024.

[41] Wright K.Plot a correlogram. Published online https://bit.ly/4bXho0k; 2021. Accessed June 20, 2024.

[42] Ashtary-Larky D, Nazary Vanani A, Hosseini SA, Rafie R, Abbasnezhad A, Alipour M. Relationship between the body fat percentage and anthropometric measurements in athletes compared with non-athletes. Zahedan J Res in Med Sci. 2018; 20(2):e10422. https://doi.org/10.5812/zjrms.10422.

[43] Hetherington-Rauth M, Baptista F, Sardinha LB. BIA-assessed cellular hydration and muscle performance in youth, adults, and older adults. Clin Nutr. 2020; 39(8): 2624-2630. https://doi.org/10.1016/j.clnu.2019.11.040.

[44] Li K, Hewson DJ, Duch^ene J, Hogrel JY. Predicting maximal grip strength using hand circumference. Man Ther. 2010; 15(6):579-585. https://doi.org/10.1016/j.math.2010.06.010.

[45] Millot F, Guilhot J, Baruchel A, et al. Growth deceleration in children treated with imatinib for chronic myeloid leukaemia. Eur J Cancer. 2014; 50(18):3206-3211. https://doi.org/10.1016/j.ejca.2014.10.007.

[46] Danneskiold-Samsøe B, Bartels EM, Bülow PM, et al. Isokinetic and isometric muscle strength in a healthy population with special reference to age and gender. Acta Physiol. 2009; 673:1-68. https://doi.org/10.1111/j.1748-1716.2009.02022.x,197Suppl.

[47] Beunen G, Thomis M. Muscular strength development in children and adolescents. Pediatr Exerc Sci. 2000; 12(2):174-197. https://doi.org/10.1123/pes.12.2.174.

[48] Faulkner JA, Larkin LM, Claflin DR, Brooks SV. Age-related changes in the structure and function of skeletal muscles. Clin Exp Pharmacol Physiol. 2007; 34(11):1091-1096. https://doi.org/10.1111/j.1440-1681.2007.04752.x.

[49] Biltz NK, Collins KH, Shen KC, Schwartz K, Harris CA, Meyer GA. Infiltration of intramuscular adipose tissue impairs skeletal muscle contraction. J Physiol. 2020; 598(13):2669-2683. https://doi.org/10.1113/JP279595.

[50] Hu K, Deya Edelen E, Zhuo W, et al. Understanding the consequences of fatty bone and fatty muscle: how the osteosarcopenic adiposity phenotype uncovers the deterioration of body composition. Metabolites. 2023; 13(10):1056. https://doi.org/10.3390/metabo13101056.

[51] Casanova N, Willig R, Soares D, et al. Relationship between anthropometric attributes and physical fitness levels in young male Portuguese futsal players. Open Sports Sci J. 2024; 17(1):e1875399X290477. https://doi.org/10.2174/011875399X290477240329065522.

[52] Popadic Gacesa J, Barak O, Jakovljevic DK. Body mass index and body fat content in elite athletes. Exerc Qual Life. 2011; 3(2):43-48. https://doi.org/10.31382/EQOL201102065P.

[53] Cole TJ, Lobstein T. Extended international (IOTF) body mass index cut-offs for thinness, overweight and obesity. Pediatr Obes. 2012; 7(4):284-294. https://doi.org/10.1111/j.2047-6310.2012.00064.x.

[54] Okada T, Huxel KC, Nesser TW. Relationship between core stability, functional movement, and performance. J Strength Condit Res. 2011; 25(1):252-261. https://doi.org/10.1519/JSC.0b013e3181b22b3e.

[55] Liu Y, Zhang F, Gan L, et al. Associations between waist circumference and executive function among Chinese Tibetan adolescents living at high altitude. Front Nutr. 2023; 10:996785. https://doi.org/10.3389/fnut.2023.996785.

[56] Castillo C, Carnicero JA, de la Torre MÁ, et al. Nonlinear relationship between waist to hip ratio, weight and strength in elders: is gender the key? Biogerontology. 2015; 16(5):685-692. https://doi.org/10.1007/s10522-015-9582-z.

[57] Mauvais-Jarvis F ed. Sex and Gender Factors Affecting Metabolic Homeostasis, Diabetes and Obesity. first ed. Cham, Switzerland: Springer; 2018. http://www.springer.com/series/5584. Accessed September 20, 2023.

[58] Janicijevic D, Knezevic OM, Garcia-Ramos A, Cvetic D, Mirkov DM. Isokinetic testing: sensitivity of the force-velocity relationship assessed through the two-point method to discriminate between muscle groups and participants' physical activity levels. Int J Environ Res Publ Health. 2020; 17(22):8570. https://doi.org/10.3390/ijerph17228570.

[59] Senefeld JW, Hunter SK. Hormonal basis of biological sex differences in human athletic performance. Endocrinology. 2024; 165(5):bqae036. https://doi.org/10.1210/endocr/bqae036.

[60] Sandbakk Ø, Solli GS, Holmberg HC. Sex differences in world-record performance: the influence of sport discipline and competition duration. Int J Sports Physiol Perform. 2018; 13(1):2-8. https://doi.org/10.1123/ijspp.2017-0196.

[61] Tiller NB, Elliott-Sale KJ, Knechtle B, Wilson PB, Roberts JD, Millet GY.Do sex differences in physiology confer a female advantage in ultra-endurance sport? Sports Med. 2021; 51(5):895-915. https://doi.org/10.1007/s40279-020-01417-2.

[62] Azam M, Ali A, Akbar S, Bashir M, Chung HC. Gender differences while performing an everyday perceptual-motor task. Humanities Soc Sci Rev. 2021; 9(3):1504-1513. https://doi.org/10.18510/hssr.2021.93151.

[63] Navarro M, van der Kamp J, Schor P, Savelsbergh GJP. Implicit learning increases shot accuracy of football players when making strategic decisions during penalty kicking. Hum Mov Sci. 2018; 61:72-80. https://doi.org/10.1016/j.humov.2018.07.004.

[64] Lulic-Kuryllo T, Inglis JG. Sex differences in motor unit behavior: a review. J Electromyogr Kinesiol. 2022; 66:102689. https://doi.org/10.1016/j.jelekin.2022.102689.

[65] Helsen WF, Starkes JL. A multidimensional approach to skilled perception and performance in sport. Appl Cognit Psychol. 1999; 13(1):1-27. https://doi.org/10.1002/(SICI)1099-0720(199902)13:1<1::AID-ACP540>3.0.CO;2-T.

[66] Dorø E, Martin R, Ratel S, Duchø P, Bedu M, Van Praagh E. Gender differences in peak muscle performance during growth. Int J Sports Med. 2005; 26(4):274-280. https://doi.org/10.1055/s-2004-821001'Published.

[67] Toskić L, Dopsaj M, Toskić D, Marković M. Isokinetic muscle power of the knee extensor and flexor muscles among differently trained people in relation to gender. Hum Mov. 2020; 21(3):81-89. https://doi.org/10.5114/hm.2020.91349.

[68] Handelsman DJ, Hirschberg AL, Bermon S. Circulating testosterone as the hormonal basis of sex differences in athletic performance. Endocr Rev. 2018; 39(5):803-829. https://doi.org/10.1210/er.2018-00020.

[69] Grund A, Krause H, Kraus M, Siewers M, Rieckert H, Müller MJ. Association between different attributes of physical activity and fat mass in untrained, endurance- and resistance-trained men. Eur J Appl Physiol. 2001; 84(4):310-320. https://doi.org/10.1007/s004210000369.

[70] Zech A, Hollander K, Junge A, et al. Sex differences in injury rates in team-sport athletes: a systematic review and meta-regression analysis. J Sport Health Sci. 2022; 11(1):104-114. https://doi.org/10.1016/j.jshs.2021.04.003.

[71] Hill AV, Sec RS. The heat of shortening and the dynamic constants of muscle. Proc R Soc Lond B Biol Sci. 1938; 126(843):136-195. https://doi.org/10.1098/rspb.1938.0050.

[72] Drouin JM, Valovich-mcLeod TC, Shultz SJ, Gansneder BM, Perrin DH. Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity, torque and position measurements. Eur J Appl Physiol. 2004; 91(1):22-29. https://doi.org/10.1007/s00421-003-0933-0.

[73] Gomes M, Santos P, Correia P, Pezarat-Correia P, Mendonca GV. Sex differences in muscle fatigue following isokinetic muscle contractions. Sci Rep. 2021; 11(1):8141. https://doi.org/10.1038/s41598-021-87443-0.

[74] Hunter SK, Angadi S, Bhargava A, et al. The biological basis of sex differences in athletic performance: consensus statement for the American College of Sports Medicine. Med Sci Sports Exerc. 2023; 55(12):2328-2360. https://doi.org/10.1249/MSS.0000000000003300.

[75] Falk B, Brunton L, Dotan R, et al. Muscle strength and contractile kinetics of isometric elbow flexion in girls and women. Pediatr Exerc Sci. 2009; 21(3):354-364. https://doi.org/10.1123/pes.21.3.354.