Nov 27 – Cardiorespiratory Endurance
The decrease in muscle mass is a big factor in the decrease of anaerobic power. We
aren’t able to provide energy to the body as quickly as well. As we age, our
buffering capacity decreases as well.
Anaerobic Responses in Adulthood
• Anaerobic performance is stable
• Training – if we train, research has shown that we can almost halt these
decreases in anaerobic capacities. Training will maintain muscle mass and
will keep our systems working to optimal level. Our bueffering capacity wil
remain constant as well
• There is a decrease in anaerobic power
• There is also loss of muscle mass
Anaerobic Training Effects Research
• Preadolescent and adolescent boy:- there is no improvement in anaerobic
training in preadolescent and adolescent boys. There is small or no
improvement in anaerobic capacity. There is improved metabolism of energy.
Training before puberty will have little changes. However, training after
puberty will result in many changes.
• Prepubescent girls:
• Older adults – master athletes: when elders partake in activity, they can
maintain their anaerobic capacity and maintain their buffering capacity. They
can increase their rates of energy metabolism.
Aerobic Responses in Childhood
The rate limiter in sustaining activity is oxygen supply and circulation. When we
exercise, our heart rate increases, this increases blood flow, increasing cardiac
output. We also breathe faster and oxygen comes in quicker. Highly trained people
have larger stroke volume. Hypokinetic Circulation: children have hypokinetic circulation. They have lower
cardiac output than adults. Due to them having a smaller heart than adults, they
will have a lower stroke volume. Children will have a higher heart rate than adults
for a workload. Children are better at pulling oxygen from the blood into the
working muscles than adults. Children are able to metabolize quicker than adults.
Heart rate: as we exercise longer, our heart rates will come back down to normal.
The more trained you are, the faster your heart rate returns to normal.
Hemoglobin: children will have lower hemoglobin in the blood. They wont be able to
carry as much oxygen in the blood.
Children have an efficient system but cannot exercise for as long as adults can.
Children have smaller bodies. Children don't have the reserves needed to extend
exercise for a prolonged length of time.
Changes in Aerobic Response With Growth and Maturation
Heart Size: as we age, heart size increases. Theres an increase in stroke volume
Hemoglobin Concentration: as we grow, our hemoglobin concentration increases
Oxygen-extraction ability: as we age, our ability to extract oxygen decreases.
As we see these increases, we see an increase in duration of anaerobic activities.
With children, we don't really long anaerobic activity. Their body size and maturity
level gives us an indication of how much work they can do. The one who has
reached puberty will be able to do more work.
Relationship Between Maximal Oxygen Uptake and Age
As we age, our VO2 linearlly increases
As boys and girls age, boys improve their vo2 max while girls vo2 max tapers off
When looking at weight, we need more muscle mass to increase a VO2 max rate.
With women, they are gaining more fat mass so it wont help them increase their
When looking at children, the most important thing when looking at a child and
looking at their performance on a VO2, is body size! Not the sex of the child! When looking at kids and trying to measure their performance, a straight VO2 may
not be the best measure. Threshold levels may affect results.
Structural Changes in the Heart With Aging
In adults, our relative VO2 will peak in the 20’s and fall 1% per year. This
decline has been found in longitudinal research and cross sectionally. In
athletes, we can maintain a higher VO2 than our sedentary friends.
The main reason for decrease in VO2 is a decrease in muscle mass.
Circulatory and respiratory system experience some changes and gradual
decline as we age. There will be a progressive loss of cardiac muscle.
• Loss of cardiac muscle
• Loss of elasticity in cardiac muscle – if its not as elastic, it wont be ablet o
stretch as well, decreasing stroke volume.
• Thickening of left ventricle – the muscle for the left ventricle will thicken so it
will take up more space in the heart, making the space in the chamber