NFS284 Chapter 13 – Exercise, fitness, and health
This is how you improve your fitness. The more you exercise, the more you will adapt to
physical activity. You have to push yourself a little bit beyond your comfort zone.
Aerobics makes your heart stronger. It allows your heart to deliver oxygen to the body much
more efficiently. Therefore, you can exercise for much longer without getting tired.
As you exercise the muscle, you are also putting stress on the bone. The stress stimulates the
bone to take up calcium. If you have adequate level of calcium in the body, you will increase the
density and the strength of your bones.
Fit adult male
Unfit adult male
Exercise increases energy expenditure
Regular exercise increases muscle inreased resting energy metabolism (REE)
The BMR is higher for the regular exerciser because more muscle. You expend more energy per
pound of muscle compared to per pound of fat, so if you start changing your body composition in
favour of lean body mass, you will increase your energy requirements, even though you are not
doing any more exercise. If you exercise continually and you change the body composition, you
will increase your energy requirements, which makes it easier to maintain a healthier body
The Toll of Physical Inactivity in Canada
Exercise reduces the risk of many of these diseases. Slide 11
When you are working your muscles, you are also simultaneously putting resistance on your
bone. This stimulates the uptake of calcium into your bone, so the mineralization of bone makes
your bone stronger. This is so the bone doesn't fracture as you get older.
Strength training allows you to build muscle because it stimulates the synthesis of more muscle.
Aerobic metabolism is an efficient process. Anaerobic metabolism is important for a quick burst
of energy, but you can't sustain exercise for a long period of time.
You want to get the heart pumping as efficiently as possible. You want to get the muscle using
the oxygen to fuel exercise as efficiently as possible. You want to get the CO2 out of the body.
At rest, you are mainly using anaerobic metabolism.
Stored ATP and creatine phosphate is a 10-15 second supply of energy (e.g., a rapid su