release and utilization of fat displays remarkable rhythmicity across the 24
hour day with peak levels occurring during the sleeping period. The timing and
amplitude of these metabolic rhythms is influenced by a number of factors
including the solar light-dark cycle, sleep-wake cycle, energy status, and daily
exercise patterns. Our group has preliminary data showing that aerobic exercise
performed during the daytime enhances sleeping patterns of fat utilization in
men but not women. We believe the ability to increase fat utilization during
sleep is important for the regulation of body weight over time and it is not
known why exercise impacts sleeping fat metabolism differently in women
compared to men.
Rynders CWHR project will examine sex-differences in the effects of aerobic exercise
on fat utilization during sleep. The significance of this study is that it will
lay the groundwork for investigating factors that upregulate or downregulate
the ability to release fat from storage depots during sleep in women compared
to men. The study will also provide insight into why weight loss through
exercise differs between women and men.