Author(s): CITHERLET, T., MOTA, G., CARLETTA, M., HAYOZ, K., SILVA PEREIRA, D., MILLET, G. , Institution: UNIVERSITY OF LAUSANNE, Country: SWITZERLAND, Abstract-ID: 477

INTRODUCTION:
The elderly population is growing worldwide and has an increased risk of non-communicable diseases such as cardiovascular diseases. It is crucial to find efficient strategies to manage the associated health and financial burden. Hypoxic (HYP), blood flow restriction (BFR), and eccentric (ECC) training have emerged as training modalities of interest to counteract aging effects. Nevertheless, these interventions have never been compared. Thus, this study aimed to evaluate whether moderate-intensity intermittent training (MIIT) combined with HYP, BFR, or ECC in the elderly can induce greater effects on aerobic fitness than traditional cycling training (CON).
METHODS:
Fifty-five elderly completed four weeks of MIIT on a bicycle (3 sets of 5 min of exercise followed by 5 min of rest, with an additional set each week) in one of four conditions: HYP (fraction of inspired oxygen ~14%), BFR (cuffs pressure ~350 mmHg), ECC, and CON. For all groups, the pedaling cadence was set at 60 rpm, and exercise intensity was determined by a perceived exertion level of 14 on the 6-20 Borg scale. Aerobic fitness was assessed through a 6-min cycling test, with concomitant oxygen consumption, heart rate, stroke volume, cardiac output, and muscle oxygenation (TSI) measurements using indirect calorimetry, impedance cardiography, and near-infrared spectroscopy, respectively. Muscle oxidative capacity was evaluated through TSI measurement during repeated occlusions after exercise cessation.
RESULTS:
Post-training, all groups exhibited a significant increase in average relative power during the 6-min cycling test (CON 20±23%; HYP 7±9%; BFR 10±10%; ECC 4±24%; P<0.0001); however, these increases were not significantly different between the training modalities (P=0.071). Post-intervention, TSI decreased by -3±5% (P=0.001) and oxygen consumption increased by 9±17% (P=0.001), with no group differences. No training or group effects were found for muscle oxidative capacity, heart rate, cardiac output, and stroke volume.
CONCLUSION:
Aerobic performance was enhanced in all groups to a similar extent, highlighting the relevance of these training modalities for improving exercise capacity. Nonetheless, there were no differences between the groups in performance or physiological responses, indicating similar effectiveness across these strategies. Performance increase can be attributed to improved oxygen extraction at the muscular level rather than improved convection. The commonly claimed superiority of ECC or BFR training for muscle adaptations, along with the HYP condition for cardiovascular fitness, was not confirmed by our findings. The results rather support a personalized approach to training prescriptions, considering medical status and individual preferences.