The nutritional status of this
athlete influences her energy supply and her capacity to generate force
for movement. However, since the links between nutrition and physical movement
aren't apparent by merely looking at a body in motion, we start our search
for those connections within a skeletal muscle and its individual muscle
fibers. At this level we can begin to appreciate the role of nutrition in
physical performance.
Requirements for
energy metabolism during ongoing muscle contraction include the following:
Oxygen and fuel substrates must
be available
Heat and waste products need to
be removed
Fluid and electrolyte balance
must be maintained
Key points
Chemical energy stores within
skeletal muscles supply mechanical energy required for muscle contraction
Energy stores are present in blood,
muscle, and fat tissues
Skeletal muscle use four major
fuel sources
Exercise intensity and duration,
training status, nutritional status, and gender all affect fuel use during
exercise.
