Effects of Eccentric Training at Long Muscle Length on Functional Capacities of Elderly Adults

Condition(s) studied

Investigational drug(s) / intervention(s)

Home-based eccentric training at long muscle length: The training program will include conventional resistance exercises, with progressive increases in intensity and volume tailored to each participant's capabilities. In this condition, specific to the Arm #1, four specific exercises targeting the knee extensors and plantar flexors will be performed at long muscle lengths.

Conventional home-based training: The training program will include conventional resistance exercises, with progressive increases in intensity and volume tailored to each participant's capabilities. In this condition, specific to the Arm#2, four specific exercises targeting the knee extensors and plantar flexors will be performed in a conventional manner (i.e., at neutral or shorter muscle lengths).

Study summary

As aging leads to a decline in muscle function and overall physical performance, interventions targeting muscle strength and neuromechanical properties are critical for maintaining functional independence in older adults. Long-length eccentric training has shown promise in enhancing muscle performance, but its effects in older adults, particularly in a home-based setting, remain underexplored.

The aim of this trial is to assess whether a targeted home-based training intervention incorporating long-length eccentric contractions can enhance functional capacity and neuromechanical properties in healthy older adults. Participants will be semi-randomly allocated to one of two groups: an experimental group incorporating long-length eccentric contractions (Group 1) or a conventional resistance training group (Group 2), with group assignment stratified to ensure an equal number of men and women in each group. Each participant will complete three laboratory-based experimental sessions (i.e., two Pre-training sessions and one Post-training session) , during which five key evaluations will be conducted: (i) the 5-Time Sit to Stand test, serving as the primary outcome measure; (ii) the Timed Up and Go test; (iii) assessments of isometric and dynamic muscle strength in the knee extensors and plantar flexors; (iv) measurements of the cross-sectional areas of the vastus lateralis, rectus femoris, gastrocnemius medialis, and soleus muscles; and (v) evaluation of tendon stiffness.

Following the pre-evaluation, each participant will engage in a 24-session, semi-supervised, home-based training protocol over a period of 8 to 11 weeks. The training program will include eight exercises, with four targeting the upper limbs and four focused on the lower limbs. Group 1 will perform the lower limb exercises at long muscle lengths, while Group 2 will perform the same exercises in a conventional manner (i.e., at neutral or shorter muscle lengths). The total training volume (calculated as repetitions × sets, in arbitrary units) will be matched across both groups, ensuring that any observed differences in outcomes are attributable to the specific training modality rather than differences in workload.

Eligibility

Primary outcome measure(s)

• 5 times Sit to Stand — At baseline (i.e., prior to the start of training) and at study completion (i.e., within one week following the final training session
  The subjects will complete five times STS repetitions on a standardized armless chair. After the cue "ready, set, go!", the subjects will start performing STS repetitions as rapidly as possible from the sitting position with their buttocks touching the chair to the full standing position, with their arms crossed over the chest. Verbal encouragement will be given during the test. The STS test will finish when the subjects sit on the chair after the fifth STS repetition, and the time needed to complete the task will be recorded with a stopwatch to the nearest 0.01 s.

Trial sites (1)