Cardiovascular and skeletal muscle responses to chronic concurrent exercise using HIT and Flywheel Technology in older adults

This research program is a part of a large project “Astronaut exercise prescriptions promoting health and fitness on Earth (A-Fit)” funded by the European Space Agency. Research results have clearly shown that exercise training can offset or blunt many associated negative effects of disuse on muscle, bone and other vital, organ systems. Similar to muscle disuse or aging on earth, chronic exposure to the microgravity environment brings about skeletal muscle atrophy, and metabolic and neuromuscular dysfunction. The A-fit project goal is to validate the efficacy and feasibility of new exercise methods in healthy, injured, diseased or old populations. The efficacy of two different training (High Intensity Aerobic Interval Training vs. Eccentric Resistance Training) protocols in preventing or delaying some specific consequences of aging (sarcopenia, immunosenescence and functional decay) was evaluated. 12 active healthy male volunteers (69.4 ± 4.3 yr), recruited in compliance with the ACSM inclusion criteria, had performed 8 weeks [April–June 2013] of aerobic training (High Intensity Training (HIT)) and 8 weeks of Isoinertial Eccentric Resistance Training (IRT) [October–December 2013] performed by “Isoinertial Flywheel YoYo Technology” device. To evaluate the effects of training, volunteers were investigated in 6 occasions: 2 baseline data collections before HIT, after HIT, after 12 weeks of wash out and before IRT, after IRT and, finally, after the final 12 weeks of recovery after IRT. Data analysis allows us to highlight the main benefits of the two different workouts. Despite initial doubts about the feasibility of carrying out high-intensity workouts with elderly subjects, we found that HIT and IRT, when performed with care and customizations are absolutely safe and well tolerated by the subjects. HIT (short duration) allows us obtain results comparable to those attained with long duration, low intensity workout sessions and, simultaneously, promote the protocol adherence. The blood tests and body composition analysis showed that HIT workout affects significantly the main health-related parameters: i) fat and glucose profile and the main markers related to cardiovascular risk; ii) body composition; iii) positively change the main anthropometric parameters related to cardiovascular diseases. The efficacy of these two types of training on the efficiency of the cardiovascular system has allowed us to demonstrate that: i) HIT causes a significant increase of maximum aerobic capacity and functional capacity without affecting weekly energy expenditure; ii) even in the elderly, HIT is able to change the functionality of the systems of transport and use oxygen at both central and peripheral iii) IRT does not seem able to make significant changes in oxygen transport and extraction in the periphery. The two workouts cause a significant improvement on leg extensor muscles strength. The analysis of structures and quadriceps volume, allow us that the increase in muscle mass and the significant change in the muscle structure are obtainable even with a workout originally optimised to improve cardiovascular parameters. As confirmed in previous studies, our findings shows that exercise intensity, rather than duration, is the key factor in determining cardiac, muscle and healthy benefits, However, fundamental questions remain regarding the minimum volume of exercise necessary to improve physiological well-being, and the precise nature and magnitude of adaptations in lifestyle that can be elicited and maintained over the long-term. However, further studies should be performed to determine whether aerobic, resistance or mixed exercise programs with different intensities are able to improve health.