Lecture 4 Cardiovascular Responses To Exercise: Changes During Childhood. Development Of vO2 Max In Children

Question 1

Rest: Reductions in resting cardiac output relative to body size are accounted for by decreases in…
A) Resting heart rate
B) Stroke volume
C) Body surface area
D) a-vO2 difference

Answer 1

A) Resting heart rate

Question 2

In children between the ages of 6 and 16 years, maximal heart rate:
A) increases in proportion to body mass as children get older
B) is inversely related to changes in body mass
C) is independent of age and body mass
D) is considerably lower than in adults

Answer 2

C) is independent of age and body mass

Question 3

During dynamic exercise a greater a-vO2 difference in children versus adults compensates for what?
A) lower cardiac output
B) higher blood pressure 
C) vasodilation
D) poor fluid balance

Answer 3

A) lower cardiac output

Question 4

Which of the following statements about childrens’ submaximal responses at a given work rate is correct?
A) boys have lower stroke volumes than girls.
B) girls have higher heart rates than boys.
C) girls have faster post-exercise recovery heart rate than boys.
D) sex differences may be explained by higher haemoglobin levels in girls.

Answer 4

B) girls have higher heart rates than boys

Question 5

Which of the following is true regarding the development of VO2 max in children?
A) increases in VO2 max (expressed relative to body mass) are highly correlated with endurance performance
B) consistent with adults, levels of habitual activity in children are a useful predictor of VO2 max
C) Cardiac size increases in concert with muscle mass in order to match oxygen delivery to consumption within the exercising muscle
D) when body size and composition are taken into account, girls have greater maximal aerobic power than boys

Answer 5

C) Cardiac size increases in concert with muscle mass in order to match oxygen delivery to consumption within the exercising muscle

Question 6

As children age there is a reduction in resting cardiac ouput when expressed relative to body size. What is primarily responsible for this decline?

A) A decline in resting stroke volume
B) A decline in resting blood pressure
C) A decline in resting heart rate
D) A decline in maximal stroke volume

Answer 6

C) A decline in resting heart rate

Question 7

Some research suggests that boys have slightly higher stroke volumes and slightly lower heart rates compared with girls at a given exercise intensity. Once individuals reach adulthood what happens to these sex differences in stroke volume and heart rate?
a) The gap between the sexes is reduced, i.e. men have
marginally larger stroke volumes and marginally lower heart
rates compared with women at a given exercise intensity.
b) The gap between the sexes widens, i.e. men have substantially larger stroke volumes and substantially lower heart rates compared with women at a given exercise intensity.
C) The gap between the sexes disappears entirely, i.e. men and women have very similar stroke volumes and heart rates to each other at a given exercise intensity.
d) The gap between the sexes stays the same, i.e. there is no affect of ageing on gender differences in stroke volume and
heart rate for given exercise intensities.

Answer 7

b)
The gap between the sexes widens, i.e. men have
substantially larger stroke volumes and substantially
lower heart rates compared with women at a given exercise
intensity.

Question 8

In growing children, how do changes in cardiac size, in particular left ventricular mass, relate to changes in lean body mass?

a) Lean body mass increases first and then left ventricular mass develops 2-3 years later.
b) There is no significant relationship between left ventricular mass and lean body mass.
c) There is a negative correlation between left ventricular mass and lean body mass.
d) There is a positive correlation between left ventricular mass and lean body mass.

Answer 8

d) There is a positive correlation between left ventricular mass and lean body mass.

Question 9

Do changes in VO2max (relative to body mass) accurately
reflect improvements in endurance performance
(e.g. running performance) as children grow?
a)
No, increases in endurance performance as children grow
are independent of VO2max and are instead linked to
improvements in submaximal exercise economy.
b)
Yes, increases in endurance performance as children grow can
be accurately predicted by changes in VO2max.
C)
Yes, but only in boys. Increases in endurance performance as
boys grow can be accurately predicted by changes in their
V02max.
d)
Yes, but only in girls. Increases in endurance performance as
gilrs grow can be accurately predicted by changes in their
V02max.

Answer 9

a) No, increases in endurance performance as children grow
are independent of VO2max and are instead linked to
improvements in submaximal exercise economy.