Purpose:
The aim of the study was to determine if an 8-week-long endurance fitness training with elastic belts would increase the strength-endurance of the inspiratory muscles and lung function characteristics, and to assess whether these changes were consistent with an increase in aerobic power and exercise capacity in healthy young women.

Methods:
Twenty-two females aged 20–25 years were randomly allocated into 2 groups. The experimental group preformed 8-week-long exercises on stationary bikes with an elastic belt on the lower part of the chest. The control group underwent the same workout, without elastic belts. Vital capacity, forced vital capacity, maximal voluntary ventilation, maximal inspiratory and expiratory pressure, sustained maximal inspiratory pressure, physical activity status, and perceived exertion scores were measured. In the incremental exercise test, work capacity and maximal oxygen uptake were assessed. Tidal volume, minute ventilation (VE), oxygen uptake (VO₂), VE/VO₂, heart rate (HR), and VO₂/HR were continuously monitored. The cycle performance at the power of the ventilatory threshold was evaluated on the following day.

Results:
. The fitness training with elastic belts significantly improved the strength and strength-endurance of the inspiratory muscles, the functional cardio-respiratory capabilities, and aerobic work output. In the control group, the studied parameters were not significantly increased.

Conclusions:
Applying elastic belts to fitness endurance exercises improves the strength and strength-endurance of inspiratory muscles, cardio-respiratory capabilities, and aerobic power, which additionally raises aerobic work output in fitness training of young women.