par Carpentier, Marine ;Faoro, Vitalie
Référence 27th European Congress of Sport Science (30/08-02/09/2022: Sevilla - Spain)
Publication Publié, 2022-08-30
Poster de conférence
Résumé : INTRODUCTION : Running sports often lead to lower limb mechanical injuries, such as ligament rupture or cartilage wear. During the recovery phases, it is often advised to practice unloaded sports such as indoor cycling (IC) to maintain a good physical condition with limited mechanical stresses1. However, despite these recommendations, the injured athletes often lose cardio-pulmonary capacity and suffer from physical deconditioning when returning to the field. Therefore, we studied an alternative training that can be proposed: deep water running (DWR). DWR has previously been showed to reduce low-limb overload, improve muscle strength2 and balance3, while water resistance forces the subject to exert greater force than moving in air4. We therefore compared the cardio-pulmonary parameters during two types of continuous trainings: DWR and IC. METHODS : Eight active healthy subjects were enrolled in the study; 23±3 yo, 50% women, maximal oxygen consumption (VO2max) measured during a cyclo-ergometric cardio-pulmonary exercise test (CPET) of 42±5 ml/min/kg. All subjects performed randomly a DWR and an IC continuous training session, with a minimum 24h between both sessions. Training sessions consisted of a 5-minutes warm-up at 80% of HR at first ventilatory threshold (VT1), followed by 10 minutes training at 100% HR at VT1, 2 minutes rest and again 10 minutes at 100% HR at VT1. For the DWR session, subjects wore a flotation belt (Nabaji) and two “pool noodles” below their arms, to maintain their head and shoulders above water. Heart rate (HR), gas exchange and ventilation (VE) were measured continuously during CPET and DWR/IC training sessions with lactate levels measured 30s after exercise. Oxygen consumption (VO2), VE and lactate during DWR and IC training were compared, with VO2 and VE averaged during the last minute of the training session. RESULTS : At same HR, VO2 was significantly (p=0.0002) higher during DWR (40±7 ml/min/kg; 97±15% of VO2max) as compared to IC training (29±5 ml/min/kg; 69±13% of VO2max). At same HR, VE was significantly (p=0.0016) higher during DWR (81±20 L/min, 67±18% of VE max) as compared to IC training (55±18 L/min, 45±11% of VE max). However, lactate did not significantly differ between DWR (3.9±1.6 mmol/L; 43±22% of lactate max) and IC training (2.9±2.3 mmol/L; 33±30% of lactate max). CONCLUSION : The present results showed that when training is calibrated by HR, the VO2 and VE are higher during DWR compared to IC. This might be related to smoothened chronotropic response in a context of lower limb hydrostatic compression increasing venous return and stroke volume. Regarding the fact that DWR training is less stressful for lower limb joints and can adequately stimulate the cardio-respiratory system, DWR can be proposed as an appropriate training for injured patients in recovery. 1 Glass & al., 1995 2 Foley & al., 2003 3 Simmons & Hansen, 1996 4 Miyoshu & al., 2004