CSSD Body Composition 5

Question 1

A CSSD uses DXA to assess a 55-year-old masters female triathlete. Which body composition change is most expected compared to her values at age 30?

Accepted Answer

Decreased lean mass and increased fat mass even with maintained exercise habits

Answer

Sarcopenia (age-related muscle loss) and hormonal changes with menopause lead to decreased fat-free mass and increased fat mass, even in athletes who maintain training, making body composition monitoring important in masters athletes.

Question 2

A sports dietitian notices that a male cyclist's skinfold sum has increased 10 mm over 6 weeks despite maintained training. The most appropriate next step is:

Accepted Answer

Assess energy intake, training load changes, and stress or recovery status before making dietary changes

Answer

A meaningful increase in skinfold sum warrants a full assessment of diet, training, sleep, and stress before intervening, as multiple factors can drive fat gain and nutrition changes should be evidence-based.

Question 3

Which of the following best explains why athletes from African American backgrounds may have DXA body fat estimates that are lower than their actual fat mass?

Accepted Answer

DXA software is calibrated using European reference populations with lower bone mineral density

Answer

DXA reference equations were largely derived from European populations; African American individuals tend to have higher bone mineral density, causing DXA to over-attribute tissue to lean mass and underestimate fat mass.

Question 4

In the context of sport, what does 'percent body fat at which performance is optimized' most accurately reflect?

Accepted Answer

The individualized fat level at which power-to-weight ratio and health markers are both favorable

Answer

Optimal performance body fat is highly individual and sport-specific; it represents the balance point where power-to-weight or strength-to-weight ratio is maximized without compromising health or hormonal function.

Question 5

Which equation is most appropriate for estimating percent body fat from body density in lean, highly trained male athletes?

Accepted Answer

A population-specific equation validated in athletes, such as the Withers or Modlesky equation

Answer

Athlete-specific conversion equations account for the higher bone mineral density and lower total body water percentage in elite athletes, producing more accurate body fat estimates than general population equations.

(CSSD) Board Certified Specialist in Sports Dietetics Practice Test

(CSSD) Board Certified Specialist in Sports Dietetics Practice Test

CSSD Body Composition 5