Effects of Slow-speed Traditional Resistance Training, High-speed Resistance Training and Multicomponent Training With Variable Resistances on Molecular, Body Composition, Neuromuscular, Physical Function and Quality of Life Variables in Older Adults.

Slow-speed traditional resistance training (2-3 seconds for each concentric and eccentric phase) protocols for the elderly have involved relatively heavy loads (70-80% of maximum force) in order to increase strength and function, and has been demonstrated to be an effective strategy to improve biomarkers of health and fitness across a wide range of healthy and clinical older populations, but the results regarding the function are inconsistent in the current literature. However, several studies indicated that muscle power is a stronger predictor than strength for daily motor activities, such as fast walking, stair-climbing, and rising from a chair, and that peak muscle power was associated with functional limitations in older people. Moreover, muscle power declines earlier and at a higher rate than strength. More recently, several authors have designed high-speed resistance training programs, also calling power training or explosive-type resistance training to improve muscle power in older adults rather than strength. However, the effects of high-speed resistance training versus slow-speed traditional resistance training on functional outcomes in older adults are inconsistent, with some studies showing enhanced improvements in function, and others showing no difference in function perhaps because to the application of different training parameters, tests, functional status of the participants or the lengths of the studies. Furthermore, the effects of the high-speed training programs on others variables such as oxidative stress, bone profile or metabolic function are unknown.

On the other hand, current recommendations have recognized that a combination of aerobic activity, strength training and flexibility exercises is important for maintaining physical function in older adults. However, most studies in older individuals have examined the isolated effect of strength and endurance training programs and focused on different health-related fitness parameters. Also, due to the low rates of physical activity in older adults, especially regarding resistance training (11%), it is necessary to study the effects of other types of physical activity possibly more dynamics, like the multicomponent training. Multicomponent training is defined as a well-rounded program that includes endurance, strength, coordination, balance and flexibility exercises and is becoming increasingly popular among the older population and appears to be associated with several health benefits because has the potential to impact both cardiorespiratory and neuromuscular fitness, which both play an important role in maintaining functional fitness and quality of life.

Currently however, there is no evidence which has examined the effectiveness of high-speed resistance training and multicomponent training in older adults (>60 years) in front of slow-speed traditional training not only in respect of the physical function, but also in terms of oxidative stress, bone profile, metabolic status and quality of life. Developing an understanding of novel training strategies can ultimately provide a viable alternative to traditional modes of exercise training for a broader range of participants and increase their adherence to them.

This is a randomized clinical trial (RCT) with 4 parallel arms. The subjects will be divided in 4 groups with a randomized technique: slow-speed traditional resistance training group (TRADITIONAL), high-speed resistance training group (H-SPEED), multicomponent training group (MULTICOMPONENT) and control group (CONTROL). The subjects will be submitted to a 4-session familiarization period and then a 20-week of training program will be performed twice a week.

The TRADITIONAL group will perform 6 submaximal repetitions equivalent to 85% of the one-repetition maximum (1RM) per exercise (high intensity training sessions). The perceived exertion level on the OMNI-RES scale progressed from 6-7 (somewhat hard) in the first 4 weeks to 8-9 (hard) in the remaining 16 weeks. Control of the intensity by this method (which takes into account the grip width, band color, and number of bands) has been previously validated in young adults, middle aged adults, and older adults, and will be the first time that it will be used the validate scale for older adults in the intervention training. The number of sets per exercise progressed from 3 in the first 8 weeks to 4 in the remaining 12 weeks in both groups, with 120s of active recovery (slow rhythmic swinging of the extremities without the use of elastic bands) between sets and 90s of rest between exercises. The speed of execution of the exercises was controlled using a metronome marking the cadence (2s of concentric contraction and 2s of eccentric contraction). The training session will consist in a general warm-up, 6 resistance exercises, including 2 upper limb exercises (elbow curl and chest press), 2 lower limb exercises (lunge and standing hip abduction), and 2 exercises combining both upper and lower limbs at the same time (squat plus upright rowing and squat plus shoulder press) and finally the cooldown routine. Primarily multijoint exercises were chosen to emphasize both major and minor muscle groups.