INTRODUCTION: The gold standard for determination of maximal oxygen consumption (VO2max) is by graded exercise testing (GET) with pulmonary gas exchange measurements and is regularly used to assess fitness status. However, this methodology requires time, maximal exercise and expensive equipment and are therefore not always suitable. These limitations also applies for semi and professional football clubs. A new non-exercise VO2max prediction model using seismocardiography (SCG) at rest in combination with demographic data is now available. SCG is a measurement of precordial vibrations using an accelerometer. The prediction model is validated in normal healthy subjects, but not yet in trained athletes. The aim was to investigate the accuracy of the SCG VO2max prediction model in sub-elite (SUB) and elite (Elite) football players and the detection of changes following a pre-season training period. METHODS: 35 SUB players from the 3th and 4th best division and 10 Elite players from the best division in Denmark completed both pre and post testing. 12 SUB and 14 Elite players were lost to post testing. The SUB players were tested in 2021, hereafter the SCG VO2max prediction model was adjusted, before testing the Elite players in 2022. Testing included determination of body composition by a DXA scan (Pre: 79.0±2.3 kg and 83.1±5.2 kg (weight), 15.0±1.3% and 12.8±1.4% (fat), 66.9±1.8 kg and 68.5±4.2 kg (fat free mass) for SUB and Elite players, respectively (mean±95% CI)). Subsequently, VO2max was estimated at supine rest with the SCG recording device, SeismoFit®, placed on the lower part of sternum (Pre: 47.2±1.9 ml/min/kg (SUB) and 55.1±2.1 ml/min/kg (Elite). Lastly, a GET on a treadmill until voluntary exhaustion was performed for determination of VO2max (Pre: 57.1±1.6 ml/min/kg (SUB) and 57.8±3.3 ml/min/kg (Elite). RESULTS: Accuracy of pre testing: SCG VO2max was lower (Student`s paired t-test: p<0.0001) compared with GET for SUB, but not different for Elite (p=0.123). A positive Pearson`s correlation of r=0.56 (p<0.0001) and a standard error of estimate (SEE) of 11.4 ml/min/kg between SCG and GET VO2max was found for SUB, whereas no correlation (r= 0.50, p=0.138) and a SEE of 5.9 ml/min/kg was found for Elite. Changes from pre to post: GET VO2max increased by 2.7±0.8 ml/min/kg (SUB, P<0.0001) and 1.6±1.2 ml/min/kg (Elite, P=0.033). SCG VO2max increased by 1.7±1.2 ml/min/kg (SUB, p=0.011) and 0.1±1.3 ml/min/kg (Elite, p=0.921). No correlation between changes in SCG and GET VO2max was found for either SUB (r=-0.24, p=0.171) or Elite (r=-0.06, p=0.870). Weight was unchanged for SUB and Elite (p>0.05). CONCLUSION: The accuracy of the original SCG VO2max prediction model was poor in sub-elite football players. When the prediction model was adjusted the accuracy improved substantially and was good in elite football players. However, the SCG VO2max prediction model is not suitable for detecting changes in VO2max following a training period in a sub-elite and elite population.
© Copyright 2022 27th Annual Congress of the European College of Sport Science (ECSS), Sevilla, 30. Aug - 2. Sep 2022. Julkaistu Tekijä Faculty of Sport Science - Universidad Pablo de Olavide. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator