Effects of Resistance Training Programes At Different Intensities on Musculoskeletal, Metabolic, Lipid, Immunological, Inflammatory, Well-being and Functional Parameters in Older Adults.

The aging of the global population is recognized by the World Health Organization (WHO) as a major issue due to the disabilities and comorbidities related to this process, with women being the gender most affected. Due to the physiological and psychological age associated declines, physical activity and exercise are proven strategies for reducing the impact of aging. However, it is still unknown what kind of training program could be the most effective in reversing deleterious age-related changes in older adults. Regarding this, the type of training intensity and exercise modality are two key training parameters in exercise programming, and, therefore, different adaptations could be induced in older adults through the modification of these parameters. Furthermore, the type of training device is a significant factor and can act as a barrier or facilitator in older adults\&#39; participation in physical activities and exercise programs. Therefore, the research project primary goals are to compare the effects of resistance training programes performed at different intensities and materials during 32 weeks on a variety of physiological parameters in older adults.

This is a randomized clinical trial (RCT) with 6 parallel arms. The subjects will be divided in 6 groups with a randomized technique assigned to a 32-week of: a) progressive elastic band-based resistance training program at high intensity (HI); b) progressive elastic band-based resistance training program at moderate-high intensity (MHI-bands); c) progressive elastic band-based resistance training program at moderate intensity (MI); d) progressive elastic tubes-based resistance training program at moderate-high intensity (MHI-tubes); e) progressive water-resistance training program at moderate intensity (WMI); f) self-management control group (CG). The subjects will be submitted to a 2-session familiarization period and then a 32-week of training program will be performed twice a week.

The exercise groups engaged in progressive elastic-based (bands of tubes) resistance training twice a week with three to four sets of six (HI), 10 (MHI) or 15 (MI) submaximal repetitions including six overall body exercises at a rate of perceived exertion (RPE) of 6-7 in the first four weeks and 8-9 in the remaining weeks on the OMNI-Resistance Exercise Scale (RES). The water-resistance group will perform similar exercises adapted to the water environment at maximal effort (maximal speed in the concentric and eccentric phases of each repetition) during 40 seconds. Members of the control group were instructed to continue their everyday lives.

Oxidative stress, bone health, body composition, neuromuscular strength, physical function, quality of life, lipidic, immune and cardiometabolic profile will be assessed. Oxidative stress status will be assessed in deoxyribonucleic acid (DNA) (urinary 8-oxo-2-deoxyguanosine \[8-oxo-dG\], lipids (F2-isoprostanes\[8-iso-P\]; malonaldehyde \[MDA\], and proteins (protein carbonyls) products together with antioxidant enzymes (superoxide dismutase \[SOD\] and glutathione peroxidase \[GPx\]), and thiol redox state (reduced glutathione \[GSH\], oxidized glutathione \[GSSG\], and the GSSG/GSH ratio. Bone health will be integrated by measures of areal bone mineral density (aBMD) and the T-score of the lumbar spine (L1-L4 segments, L2-L4 segments, and L1, L2, L3, and L4 individual vertebrae) and proximal femur (femoral neck, trochanter, intertrochanter, Ward\&#39;s triangle, and total hip in both projects) will be assessed by dual-energy X-ray absorptiometry (DXA). Additionally bone health will be also composed by fracture risk (the 10-year probability of a major osteoporotic fracture and the 10-year probability of a hip fracture), bone turnover markers (BTMs) of bone formation (procollagen type I N propeptide \[P1NP\], a bone-specific isoform of alkaline phosphatase \[bALP\]) and bone resorption (a β-isomerized form of C-terminal telopeptide of type I collagen \[β-CTx\]), and their relationship (bALP/ β-CTx ratio). Body composition (total body mass, total fat mass, total fat-free mass, and total body fat percentage) will be measured by DXA. Moreover, the neuromuscular strength of upper limbs (elbow flexor and extensor muscles) and lower limbs (hip abductor and hip adductor along with knee flexor and extensor muscles) will be assessed through isokinetic dynamometry at low (60°/s) and high (180°/s) velocities. Finally, physical performance will be measured using various functional tests and batteries widely used in the literature, such as the 30 seconds chair stand (30sec-CS) and 30 seconds arm curl (30sec-AC) for muscle strength/endurance of the lower and upper limbs; time up and go (TUG) for dynamic balance/agility; the six-minute walking test (6MWT) for aerobic endurance; five sit-to stand.

Eligibility Criteria:
Inclusion Criteria:

* Age \&gt; 60 years
* Physically independent (able to walk 100 m without a walking aid and climb 10 steps without rest)
* On the registration waiting list for physical activity at their respective Municipal Activity Centers for Older People (MACOP).
* Sedentary lifestyle (less than one hour of physical activity or exercise a week during the previous six months).
* Medical certificate of suitability or fitness to practice resistance training activities.
* No plans to leave the area during the intervention.
* Cognitive ability to understand and follow the instructions and sign the informed consent form.
* Free of any antioxidant supplements for at least six weeks before the start of this study.

Exclusion Criteria:

* Presence of cardiovascular, musculoskeletal, renal, liver, pulmonary, or neuromuscular and neurological disorders that would prevent the participant from performing the exercises.
* Current or prior (past six months) use of hormone replacement therapy.
* Body weight changes \&gt; 10% in the previous year.
* Intake of prescription medications or supplements (e.g., vitamins C, E) that were expected to alter the results of the study (ergogenic, dietary aids, estrogen, beta-blockers, steroid hormones, calcitonin, corticosteroids, glucocorticoids, thiazide diuretics, anticonvulsants, bisphosphonates, raloxifene).
* A history of malignant neoplasms.
* Terminal illness with life expectancy of less than one year.
* Engagement in regular strength training (more than once a week) during the previous six months.
* Participation in another research project (within the last six months) involving dietary, exercise, and/or pharmaceutical intervention.
* Mini mental State Examination lower than 23/30.
* Severe visual or hearing impairment.