Answer :
Final answer:
Alex's basal metabolic rate (BMR) is influenced by factors such as her body surface area, weight, age, gender, and body fat percentage. Her height and weight suggest she might have a higher BMR due to a larger body surface area. However, without specific calculations using the Harris-Benedict equation or similar, we cannot provide an exact number for Alex's BMR.
Explanation:
The basal metabolic rate (BMR) is the amount of energy expended while at rest in a neutrally temperate environment, in the post-absorptive state (meaning that the digestive system is inactive, which requires about 12 hours of fasting in humans). The BMR affects and is affected by several factors such as body surface area, weight, age, gender, and body fat percentage. Alex's BMR can be influenced by her height, weight, and exercise habits.
Body surface area tends to correlate well with BMR and taller, thinner individuals usually have a higher BMR. Given Alex's height of 5'8" and a weight of 145 lbs, her body surface area would be a significant factor. Additionally, the metabolic rate for females declines more rapidly from the ages of 5 to 17 compared to males, but Alex is 20 years old, so her BMR would be moderately affected in this regard.
Since Alex has healthy eating habits and exercises three times a week, she would likely have a lower body fat percentage and, consequently, a higher BMR, as muscle tissue consumes more energy than fat tissue at rest. Nevertheless, one would typically need to use the Harris-Benedict equation or similar, which includes factors like age, weight, height, and gender, to calculate an individual's precise BMR.