Results
Subjects in the training group were able to gradually
increase their daily distance swum from the start of this
investigation (Fig. 1). For the first 3 weeks (30–40 min
per session), subjects swam 879 ± 54 to 1235 ± 93 m/day.
During the final week, subjects averaged 1591 ± 80 m/day.
The mean distance swum during week 10 was significantly
(P < 0.001) greater than that during week 4 (the
start of the 45 min per session swimming). The swimming
training group completed an average of 94% of the
scheduled exercise sessions.
The energy intake and dietary composition estimated
from dietary records did not differ between before and
after swimming training. There were no significant
changes in total energy intake and macronutrient intake.
Potentially confounding variables for arterial blood
pressure, including alcohol (5 ± 3 versus 7 ± 4 g/day) and
sodium (3346 ± 390 versus 3440 ± 359 mg/day) intakes,
also did not differ between before and after training.
The body composition data are presented in Table 1.
Although obesity was not an inclusion criterion, all of the
subjects were obese. Their mean body fat percentages
prior to the study were 36 ± 2% for the training group and
36 ± 4% for the control group. There were no significant
differences in body mass and body composition between
the groups. Neither training nor control group members
experienced significant changes in body mass, lean body
mass and relative percentage of body fat during the study.
Swimming training resulted in a significant (P < 0.05)
reduction in resting heart rate whereas the mean heart rate
value for the control group was not altered (Table 2).
Systolic, diastolic, and mean arterial blood pressures in the
control group at seated rest did not change during the
study. In contrast, there was a significant (P < 0.05) reduction
in seated systolic blood pressure in the swimming
training group after 10 weeks of swimming training. It is
important to note that the seated systolic blood pressure
decreased in 11 of 12 subjects in the training group. The
reduction in systolic blood pressure was approximately
6.6 mmHg from an initial value of 150 ± 5 mmHg. Seated