Sex Differences

Question 1

What are the differences in hormones between males and females?

Answer 1

Males: Testosterone
Females: oestrogen, progesterone

Question 2

What are the differences in body size and composition between males and females?

Answer 2

Females lighter and shorter than males have more body fat, less fat-free mass and smaller surface area.
Females have gynoid shape (fat around lower body), males have an android shape.

Question 3

What are the differences in muscular strength and power between males and females?

Answer 3

Males are generally more powerful, females 2/3 as strong as males. Males stronger due to increased muscle CSA
Females have greater type 1 fibres (endurance)

Question 4

What are the differences in VO2 max between males and females? why?

Answer 4

Females have lower VO2 max than males caused by lower Hb and slightly lower SV and Q

Question 5

What are the differences in the pulmonary system between males and females?

Answer 5

Lung capacities and size are related to body size.
Females have a higher Ve working a higher %VO2 max for a given absolute workload. Ve is similar when workload is relative.

Question 6

What are the differences in cardiovascular function between males and females?

Answer 6

women have smaller hearts and less plasma volume leading to smaller Q and SV and a higher submaximal HR

Question 7

What are the differences in metabolism and substrate usage between males and females?

Answer 7

Females have lower BMR due to less muscle.
Females have lower RER, rely on lipids has a glycogen sparing effect, may lead to lower HLa- when exercising at a similar intensity.
- Women may be more fatigue resistant

Question 8

How does oestrogen affect substrate usage?

Answer 8

• decreased gluconeogenesis and insulin binding capacity

- increased mobilisation and oxidation of FFA

Question 9

How does progesterone affect substrate usage?

Answer 9

• decrease glucose intake into adipose tissue
• decrease gluconeogenesis
• increase hepatic glycogen storage
• decrease insulin sensitivity
• increase FFA storage

Question 10

How do hormonal contraceptives alter the menstrual cycle?

Answer 10

Contain estradiol and progestogen which inhibit endogenous hormone synthesis. Allows control over cycle.

Question 11

What effect does the menstrual cycle have on exercise physiology?

Answer 11

Females have delayed sweating response during luteal phase = slightly faster increase in core temp (0.5 degrees higher during luteal phase). Possible increased VE, increased hypoxic (low O2) and hypercapnic (high CO2) ventilatory response during luteal phase.
Does not affect CV function during exercises, substrate usage or muscular function.

Question 12

What effect does the menstrual cycle have on exercise performance?

Answer 12

• some debate

- hormones changes could alter substrate usage, core temp and ventilation.

Question 13

Describe the effect of exercise on menstrual function

Answer 13

Excessive levels of physical activity have been associated with amenorrhoea

Question 14

What is eumenorrhoea?

Answer 14

normal menses

Question 15

What is amenorrhoea?

Answer 15

later onset or loss of menses

Question 16

What is primary amenorrhoea?

Answer 16

when menses has not occurred by 16 or secondary sexual characteristics aren’t present by 14 yrs

Question 17

What is secondary amenorrhoea?

Answer 17

Absence of menses for > 3 consecutive months after onset of menarche

Question 18

What is Oligomenorrhoea?

Answer 18

intermittent menses

Question 19

What causes athletic amenorrhoea?

Answer 19

Insufficient energy intake is the primary cause. Leads to decreased GnRH which leads to decreased oestrogen and LH, leads to increased cortisol

Question 20

What is relative energy deficit in sports (RED-S)?

Answer 20

Impaired physiological function caused by relative energy deficiency;
including metabolic rate, menstrual function, bone health, immunity, protein synthesis, cardiovascular and psychological health