Individualized Versus Non-Individualized Resistance Training

A Tailored Intervention to Prevent Age-Related Declines in Muscle Power and Functional Ability

Preserving functional ability is crucial for healthy aging. Unfortunately, age-related decreases in muscle power often lead to declines in functional ability. As power is the product of force and velocity, decreases in power can originate from changes in muscle force, contraction velocity, or both, varying between individuals. The primary method to prevent functional disability is power-based resistance training. Although training interventions are effective for most older adults, they do not induce substantial improvements in a subset of the population. These inconsistent outcomes may arise from neglecting the observed differences in the force-velocity (F-V) profiles between individuals. Therefore, this study provides a novel approach to resistance exercise, in which exercise dose is tailored according to the individual's F-V profile. The effectiveness of the tailored method will be assessed in a randomized control trial, comparing the effects of an individualized and a non-individualized 12-week training intervention on muscle power parameters and functional ability.

Study Overview

• Status: Completed
• Conditions: Exercise Training
• Intervention / Treatment: Other: 12-week progressive power-oriented resistance exercise program

• Study Type: Interventional
• Enrollment (Actual): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Vlaams-Brabant
    • Leuven, Vlaams-Brabant, Belgium, 3000
      • KU Leuven - Department of Movement Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Community-dwelling adults
• At least 65 years old

Exclusion Criteria:

• Systematic engagement in resistance exercise during the past year
• Unstable cardiovascular disease, neuromuscular disease, acute infection or fever
• Recent surgery
• Lower-extremity injuries
• Low levels of functional ability (i.e., SPPB score ≤ 9)
• Cognitive malfunctioning (i.e., Mini-Mental State Examination < 24)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Individualized resistance exercise program; Individualized exercise dose. All individuals perform resistance exercises at a load that targets their deficit. Individuals with a velocity deficit train at low loads while individuals with a force deficit train at high loads.	Other: 12-week progressive power-oriented resistance exercise program; 2x/week, 35-45 min sessions, on leg press machine
Active Comparator: Non-individualized resistance exercise program; Non-individualized exercise dose. All individuals perform resistance exercises at a load that does not target their deficit. Individuals with a velocity deficit train at high loads while individuals with a force deficit train at low loads.	Other: 12-week progressive power-oriented resistance exercise program; 2x/week, 35-45 min sessions, on leg press machine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal power (Pmax)	Participants performed explosive unilateral leg extensions with the dominant leg at five submaximal loads on a pneumatic leg press (Leg Press Air 400, Keiser, USA). Submaximal loads were scaled to the estimated maximal isometric force derived from the familiarization session. The three lighter loads were performed three times each and the two heavier loads twice, with the repetition yielding the highest mean concentric velocity retained for analysis. Participants subsequently performed single repetitions at incrementally increasing loads until 1-RM was reached. Rest intervals were adjusted according to the load of the preceding trial: 60 s after the three lightest loads, 90 s after the two heavier loads, and 120 s during the incremental trials leading to 1-RM. For each load, the mean concentric velocity of the best trial was used to establish the individual force-velocity (F-V) relationship using linear regression, from which the maximal power (Pmax; W) was estimated.	Change from baseline at 6 and 12 weeks
Maximal isometric force (F0)	Participants performed explosive unilateral leg extensions with the dominant leg at five submaximal loads on a pneumatic leg press (Leg Press Air 400, Keiser, USA). Submaximal loads were scaled to the estimated maximal isometric force derived from the familiarization session. The three lighter loads were performed three times each and the two heavier loads twice, with the repetition yielding the highest mean concentric velocity retained for analysis. Participants subsequently performed single repetitions at incrementally increasing loads until 1-RM was reached. Rest intervals were adjusted according to the load of the preceding trial: 60 s after the three lightest loads, 90 s after the two heavier loads, and 120 s during the incremental trials leading to 1-RM. For each load, the mean concentric velocity of the best trial was used to establish the individual force-velocity (F-V) relationship using linear regression, from which maximal isometric force (F0; N) was estimated.	Change from baseline at 6 and 12 weeks
Maximal unloaded velocity (V0)	Participants performed explosive unilateral leg extensions with the dominant leg at five submaximal loads on a pneumatic leg press (Leg Press Air 400, Keiser, USA). Submaximal loads were scaled to the estimated maximal isometric force derived from the familiarization session. The three lighter loads were performed three times each and the two heavier loads twice, with the repetition yielding the highest mean concentric velocity retained for analysis. Participants subsequently performed single repetitions at incrementally increasing loads until 1-RM was reached. Rest intervals were adjusted according to the load of the preceding trial: 60 s after the three lightest loads, 90 s after the two heavier loads, and 120 s during the incremental trials leading to 1-RM. For each load, the mean concentric velocity of the best trial was used to establish the individual force-velocity (F-V) relationship using linear regression, from which maximal unloaded velocity (V0; m/s) was estimated.	Change from baseline at 6 and 12 weeks
Force-velocity slope	Participants performed explosive unilateral leg extensions with the dominant leg at five submaximal loads on a pneumatic leg press (Leg Press Air 400, Keiser, USA). Submaximal loads were scaled to the estimated maximal isometric force derived from the familiarization session. The three lighter loads were performed three times each and the two heavier loads twice, with the repetition yielding the highest mean concentric velocity retained for analysis. Participants subsequently performed single repetitions at incrementally increasing loads until 1-RM was reached. Rest intervals were adjusted according to the load of the preceding trial: 60 s after the three lightest loads, 90 s after the two heavier loads, and 120 s during the incremental trials leading to 1-RM. For each load, the mean concentric velocity of the best trial was used to establish the individual force-velocity (F-V) relationship using linear regression, from which the F-V slope (Ns/m) was derived.	Change from baseline at 6 and 12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Short Physical Performance Battery (SPPB)	Total score on the SPPB (min 0, max 12, higher scores indicate better performance)	Score at baseline
Hand grip strength	Maximal grip strength (kg) of the dominant hand using an isometric dynamometer adjusted for hand size	Change from baseline at 6 and 12 weeks
Maximal gait speed	The average time (s) to walk 10m as fast as possible	Change from baseline at 6 and 12 weeks
Countermovement jump	The jump height (mm) in a countermovement jump	Change from baseline at 6 and 12 weeks
Timed up-and-go	The time (s) needed to stand up from a chair, walk 3 m, turn, walk back and sit down again as fast as possible	Change from baseline at 6 and 12 weeks
5-repetition sit-to-stand time	The time (s) needed to complete the 5-repetition sit-to-stand test	Change from baseline at 6 and 12 weeks
5-repetition sit-to-stand power	The average power (watt) produced during the 5-repetition sit-to-stand test	Change from baseline at 6 and 12 weeks
30-second sit-to-stand repetitions	The number of repetitions completed during the 30-second sit-to-stand test	Change from baseline at 6 and 12 weeks
30-second sit-to-stand power	The average power (watt) produced during the 30-second sit-to-stand test	Change from baseline at 6 and 12 weeks
Stair ascent time	The time (s) needed to ascend a flight of stairs	Change from baseline at 6 and 12 weeks
Stair ascent power	The average power (Watt) produced during the stair ascent test	Change from baseline at 6 and 12 weeks
Exercise adherence	Number of sessions attended as a percentage of total sessions planned	Total adherence over 12-week period
Absolute training load	The absolute load (kg) used during training sessions	Consistently recorded throughout the 12-week intervention
Relative training load	The relative load (%1RM) used during training sessions	Consistently recorded throughout the 12-week intervention
Number of repetitions	The number of repetitions (n) completed per set	Consistently recorded throughout the 12-week intervention
Highest movement velocity within a set	The velocity (m/s) of the fastest repetition in a set (Vmax)	Consistently recorded throughout the 12-week intervention
Lowest movement velocity within a set	The velocity (m/s) of the slowest repetition in a set (Vmin)	Consistently recorded throughout the 12-week intervention
Velocity loss	The percentage difference between the highest and lowest movement velocity in a set = ([Vmax - Vmin] / Vmax) × 100	Consistently recorded throughout the 12-week intervention
Set-volume index	The number of repetitions × relative load (%1-RM) per set	Consistently recorded throughout the 12-week intervention
Session-volume index	The sum of set volumes per session	Consistently recorded throughout the 12-week intervention

Collaborators and Investigators

• Sponsor: Universitaire Ziekenhuizen KU Leuven

Publications and helpful links

General Publications

• Deboutte J, Delecluse C, Thomis M, Van Roie E. The Effects of Force-Velocity Profile-Based Load Prescription on Muscle Power and Functional Performance in Velocity-Deficient Older Adults. Scand J Med Sci Sports. 2026 Nov;36(11):e70392. doi: 10.1111/sms.70392.

Study record dates

Study Major Dates

• Study Start (Actual): May 20, 2024
• Primary Completion (Actual): December 4, 2025
• Study Completion (Actual): December 4, 2025

Study Registration Dates

• First Submitted: March 5, 2024
• First Submitted That Met QC Criteria: June 5, 2024
• First Posted (Actual): June 10, 2024

Study Record Updates

• Last Update Posted (Actual): November 6, 2026
• Last Update Submitted That Met QC Criteria: November 5, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: S68434

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No