Lecture 16 - Sex Differences Flashcards
testosterone leads to…
- inc bone formation, larger bones
- inc protein synthesis, larger muscle
- inc EPO secretion, inc red blood cell production
estrogen leads to…
- inc fat deposition (lipoprotein lipase)
- faster, more brief bone growth
- shorter stature, lower total body mass
- inc fat mass, percent body fat
muscle strength between sexes
Muscle strength differs between sexes
upper body: women 40-60% weaker
lower body: women 25-30% weaker
- due to total muse mass difference, NOT
difference in innate muscle mechanisms
No strength disparity when expressed per unit of muscle cross-sectional area
Causes of upper body strength disparity
- women have more muscle mass in lower body
- women utilize lower body strength more
- altered neuromuscular mechanisms
this is not necessarily tru in 2023 - women have smaller cross sectional area
proportion of muscle fibre types in men vs women
Men
1. Type 2a
2. type 1
3. type 2x
Women
1. type 1
2. type 2a
3. type 2x
important when considering strength vs aerobic disparities
physiological response of the cardiovascular system to acute exercise
- CVS function differs greatly between M/F
For same ABSOLUTE submaximal workload - same CO
- Women: lower stroke volume, Higher HR (compenstory)
- smaller hearts, lower blood volume
For same RELATIVE submaximal workload - Women: HR slightly inc, SV dec, CO dec
- leads to dec O2 consumption
how do women compensate for decreased amounts of hemaglobin (at submaximal intensity)
compensate or decrease hemaglobin via increasing (a-v)O2 differences
- lower hemaglobin means lower oxidative potential
- (a-v)O2 difference untimately limited, too
sex differences that we see in respiratory function
- differences are due to differences in lung volume, and body size
- similar breathing frequency at same relative workload
- women increase frequency at same absolute workload
are untrained and trained physiological responses to acute exercise fair when doing sex comparisons
Womens VO2 < Mens VO2
Untrained sex comparisons are unfair
- considering past dats, the male test subjects were non athletes but active and female were sedentary non athletes
Trained sex comparisons are better
- similar level of condition between sexes
which factors limit womens VO2 max
womens lower hemoglobin and lower CO
- SV limited by heart size, plasma volume
- plasma volume loading in womens help
sex differences in lactate and lactate threshold
- peak lactate concentration lower in women
- women are more type 1
- lactate threshold occurs at same percent of VO2
body comp changes in M/W with exercise training
- decrease in total body mass, fat free mass, percent body fat
- increase in FFM (more with strength vs endurance)
- weight bearing exercise maintains bone mineral density
- connective tissue injury not related to sex (biomechanics plays the role, not physiological)
~~same in men and women~~
strength gains in M/W
- less hypertrophy in women vs men, though some studies show similar gains
- neural mechanism more important for women
- for a given BW, trained men have more FFM than trained women (consider fewer trained women in studies)
cardioRespiratory adaptations to exercise training
CRS changes are not sex specific
are VO2 changes sex specific
NO
- both will adapt with training
- lactate threshold wil increase
- blood lac for given work rate dec.
