Effectiveness of individualized training based on force–velocity profiling on physical function in older men

Abstract

The study aimed to investigate the effectiveness of an individualized power training program based on force–velocity (FV) profiling on physical function, muscle morphology, and neuromuscular adaptations in older men. Forty‐nine healthy men (68 ± 5 years) completed a 10‐week training period to enhance muscular power. They were randomized to either a generic power training group (GPT) or an individualized power training group (IPT). Unlike generic training, individualized training was based on low‐ or high‐resistance exercises, from an initial force–velocity profile. Lower‐limb FV profile was measured in a pneumatic leg‐press, and physical function was assessed as timed up‐and‐go time (TUG), sit‐to‐stand power, grip strength, and stair‐climbing time (loaded [20kg] and unloaded). Vastus lateralis morphology was measured with ultrasonography. Rate of force development (RFD) and rate of myoelectric activity (RMA) were measured during an isometric knee extension. The GPT group improved loaded stair‐climbing time (6.3 ± 3.8 vs. 2.3% ± 7.3%, p = 0.04) more than IPT. Both groups improved stair‐climbing time, sit to stand, and leg press power, grip strength, muscle thickness, pennation angle, fascicle length, and RMA from baseline (p < 0.05). Only GPT increased loaded stair‐climbing time and RFD (p < 0.05). An individualized power training program based on FV profiling did not improve physical function to a greater degree than generic power training. A generic power training approach combining both heavy and low loads might be advantageous through eliciting both force‐ and velocity‐related neuromuscular adaptions with a concomitant increase in muscular power and physical function in older men.

The effects of being told you are in the intervention group on training results: a pilot study

“…There were no significant differences in any of the included measures regarding the effectiveness of the "individualized training", independent of the placebo group allocation (Table 3 ). To the authors' knowledge, eight experimental studies have evaluated the effectiveness of individualized training based on force–velocity profiling 13 – 20 . Four studies did not find any effects in favor of individualized training based on the FV-profile 17 – 20 .…”

“…All participants lay supine on an examination bench with knees fully extended. The measurement was taken at ~ 40% from the lateral epicondyle of the knee to the great trochanter major 20 . Ultrasound settings (Gain, frequency, depth) were optimized for each subject and kept constant at each test session, to best highlight collagenous tissue that constitutes muscle aponeuroses and surrounds muscle fascicles.…”

“…Therefore, in practice, two participants can be doing the exact same workouts, but it is "optimal" for one subject and "non-optimal" for another. The concept is found to be highly effective in some studies, while other studies have yielded different findings 13 – 20 .…”

“…In practice, athletes with a "force-oriented profile" (i.e., velocity deficit) are commonly prescribed training with a focus on high-velocity exercises, whereas athletes with "velocity-oriented profiles" (i.e., force deficit) get prescribed high-force exercises. Athletes with a "well-balanced" profile, then get training prescriptions with a balanced combination of both high-force and high-velocity training 13 – 20 . When training according to the FV profiles, the subjects get "individualized" training based on a performance test.…”

“…When training according to the FV profiles, the subjects get "individualized" training based on a performance test. The performance test that determines which form of training is "optimal" is a "black box" for the participants, which makes it a perfect setup to investigate the placebo effect (i.e., participants can easily be randomized and told they get optimal or control training without knowing which is actually "optimal") 13 – 20 . Therefore, in practice, two participants can be doing the exact same workouts, but it is "optimal" for one subject and "non-optimal" for another.…”