Abstract
Behavioral modification (BM) is a strategy designed to sustain or restore well-being
through effects such as enhanced relaxation, reduced stress, and improved sleep. Few
studies have explored the role of BM delivered in the context of fitness programs
for healthy adults. Thus, the purpose of this investigation was to examine whether
BM combined with aerobic and resistance training programs would improve health and
fitness measures more than the exercise training alone. Thirty-two healthy fitness
club members (19 men) were randomized to receive a BM program (n=15) or an equal-attention
(EA) control (n=17). BM consisted of twelve, 10-min education sessions between a trained
fitness professional and the participant, coupled with weekly, individualized relaxation,
stress reduction, and sleep improvement assignments. All participants engaged in 1 h
of coached resistance training and remotely guided aerobic exercise thrice weekly
for 12 weeks. Fitness measures (aerobic performance, body composition, muscle strength
and endurance, lower-body power), sleep characteristics, and heart rate variability
(HRV) were obtained at baseline and after the 12-week program. BM resulted in greater
improvements in aerobic performance (increased maximum oxygen uptake, metabolic (lactate)
threshold, and percent of maximum oxygen uptake at which metabolic threshold occurred),
peak and average lower-body power, and body composition (decreased body fat percentage
and fat mass) compared to EA. BM also positively influenced parasympathetic tone through
increased High-frequency HRV. BM resulted in greater improvements in fitness measures,
body composition, and heart rate variability compared with EA. These findings have
intriguing implications regarding the role of BM in augmenting health and physical
performance.
Key words
behavioral modification - physical fitness - exercise - maximum oxygen uptake - heart
rate variability - sleep intervention
