Effects of Different Power Training Intensities in Older Adults

Condition(s) studied

Investigational drug(s) / intervention(s)

Moderate to high intensity (PTMH; 65-80% of 1-repetition maximum [1RM]) ): Power training performed at maximum velocity in the concentric phase with moderate to high intensity

low to moderate intensity (PTLM; 40-60% of 1-repetition maximum [1RM]): Power training performed at maximum velocity in the concentric phase with lower to moderate intensity

Study summary

Power (strength × velocity) is a crucial component for maintaining independence during aging. Therefore, investigating interventions aimed at improving this physical capacity is essential for this population. The aim of this study is to examine the effects of power training (PT) performed at low to moderate intensity (PTLM; 40-60% of 1-repetition maximum \[1RM\]) and moderate to high intensity (PTMH; 65-80% of 1RM) on muscle power, kinematic gait parameters, strength, muscle thickness, and functional performance in older adults. Participants will be randomly assigned to perform PTLM and PTMH. Data collection will occur before and after familiarization, as well as at weeks 8 and 16 of the training programs. Participants will undergo a series of tests in the following sequence: 1) muscle thickness and 1RM test; 2) muscle power, maximum voluntary contraction, and rate of force development; 3) functional performance. The primary analyses will be conducted on an intention-to-treat basis, comparing the effects of the interventions and groups over time. Generalized Estimating Equations (GEE) will be used, considering the factors of group (2 levels) and time (3 levels). Paired comparisons will be assessed using the Bonferroni post-hoc test to identify significant differences between groups and time points. All tests will be performed using JASP software (version 0.16.4.0), with statistical significance set at p \< 0.05 for all analyses.

Eligibility

Primary outcome measure(s)

• Muscle Power — Pre- and post-intervention (16 weeks of training)
  The power output during strength exercises is assessed using an encoder linear at two different intensities: 30% and 70% of 1RM in leg extension and leg press 45. Power output is the ability to generate force quickly and is a key measure of explosive strength. These tests are performed using different resistance levels to assess power across a range of intensities. Measurement Tool: Encoder linear (linear encoder or velocity-based device) Scale: Power output in watts (W) Higher scores indicate better power performance at each intensity.
• Muscle Strength — Pre- and post-intervention (16 weeks of training)
  Muscle strength is the ability of a muscle or muscle group to generate force against resistance. It reflects the maximum force that can be produced in a single effort and is essential for daily activities and overall physical function. One Repetition Maximum (1RM) is used to quantify maximal strength. Measurement Tool: 1RM testing Scale: 1RM (measured in kg) Higher scores indicate better strength performance.
• Rate of Force Development — Pre- and post-intervention (16 weeks of training)
  Rate of force development refers to the speed at which force is generated by a muscle or muscle group. It is a critical measure of neuromuscular performance, especially in activities that require explosive strength or rapid reactions. RFD is measured during maximal voluntary contractions. Measurement Tool: Load Cell Scale: Measured in Newtons per second (N/s) Higher scores indicate better neuromuscular performance.

Trial sites (1)

More Federal University of Rio Grande do Sul trials in Brazil