The Effects of Variable Load Exercise on Muscle Function and Blood Pressure Regulation: a Randomized Controlled Trail

This study is being conducted to determine whether a novel training approach (variable load exercise) is an effective countermeasure to attenuate for rapid declines in muscle power, function, contractile capacity and fiber type distribution that typically originate from aging and muscle disuse.

The present study is planned over a 24-month investigation period, including ethics application write-up, equipment calibration, participant recruitment, general health examination, familiarization trails, pilot study, data collection in the main portion of the study, data analysis and paper write-up for peer-review journal.Collaboration with Institute for Kinesiology Research of Koper (a municipality in Slovenia), University of Split, University of Udine and Padua is planned. In addition, recruitment of students of Applied Kinesiology at University of Primorska, to collaborate on data collection so they could use data acquired to write their final papers or master thesis is also planned.

After obtaining ethical approval, seniors will be recruited from the Primorska region in Slovenia, via presentations in Daily Activity Centers, social medial and local newspaper. Exclusion and inclusion criteria will be applied as outlined in the next paragraph and those applicants remaining will be randomized into different groups. Data collection will be carried out on eight separate occasions, including familiarization, pilot testing, main portion of the study and follow up data collection, in a randomized counter balance crossover fashion. Following familiarization and pilot study all participants will be randomly assigned to either (I) RT or (II) variable load exercise (VLE) before a crossover of experimental protocols is executed, after a minimum washout period (2x times the duration of experimental protocol) and a follow-up measurement will take place two weeks after experimental protocols are completed. Each participant will be allocated into RT or VLE with pre/post measurements preceding each condition, for eight consecutive weeks following a structured linear periodization model, previously used in healthy older adults (Colon et al., 2017). In total of 2 weeks of familiarization period (to ensure reliability of assessment and avoid learning effects), 4 weeks of pilot study (comparing old and young participants) 16 weeks of different training protocols (RT and VLE, plus 4 weeks of washout period) accompanied with follow-up measurements two weeks after completing training protocols, since training effects are in general dose-dependent and their effects are reversible. Lastly, testing procedures will be conducted at the same facility, by the same researchers using the same equipment at the similar time of the day across the investigation.

The selection of participants will consist of both male and female adults established on a purely voluntary basis. We will follow a strict inclusion and exclusion criteria (in brief):

1. Inclusion criteria: (Signed informed consent and doctor's permission; Age >50 years)
2. Exclusion criteria: (Any cardiovascular disease or ECG examination abnormalities (at rest and under load); hypertension (resting BP > 140/90 mm Hg); previous history of musculoskeletal and neurological disorder/injury; previous history of neurological disorders; supplement or drug consumption that may interfere with training outcomes; alcohol consumption and smoking; BMI >30 kg/m2).