Design of the study and PA protocol
The study was a 12-week randomized controlled trial that
started in April (T0) and ended in July 2013 (T1), structured in three
physical training sessions per week (36 sessions in all) of 1-h
duration. The participants were instructed not to modify their
usual daily activities and dietary habits and not to engage in any
supplemental physical routine program for the entire duration of
the program. They were also informed that a maximum of three
days of absence, even not consecutive, was allowed before
excluding them from the study.
According to the American College of Sports Medicine (ACSM)
guidelines [7] the training intensity for the VPA group was set to
reach a value of the percentage of Heart Rate Reserve (%HRR
defined according to Karvonen, Kentala, & Mustal, 1957) in the
60–84% range. To this end, the HR signal was monitored during the
activity by means of a Polar1 T31 CodedTM transmitter (Polar,
Kempele, Finland) and also remotely transmitted using a Hosand1
Group Telemetry system (Hosand Technologies, Verbania, Italy) to
fitness professionals for continuous analysis during the session.
The individual HRR for each participant (i.e. the difference between
the maximal and the resting state heart rate) was calculated on
the basis of the maximal heart rate value (HRmax) derived from