What significantly improves during physical activity?

• A. Blood pressure
• B. Glucose intolerance & insulin sensitivity
• C. Bone mineral density
• D. Resting heart rate

Answer: (B)

During activity, the body's ability to handle glucose improves markedly because exercising muscles demand more glucose and become highly efficient at taking it up. This happens quickly as GLUT4 transporters move to the muscle cell surface to increase glucose uptake, even before insulin acts. With regular training, the muscles’ responsiveness to insulin also improves, helping insulin to more effectively promote glucose uptake and regulate liver glucose production. The net result is better glucose tolerance and higher insulin sensitivity, which reduces the risk of impaired glucose metabolism and type 2 diabetes.

Other options don’t show this same robust metabolic change in the same way. Blood pressure rises during exercise as a normal acute response, not an improvement. Resting heart rate tends to decrease over time with training, rather than something that changes during activity. Bone mineral density increases with long-term, load-bearing training but changes are gradual and depend on sustained mechanical loading. The standout benefit tied to exercise is the significant improvement in glucose handling and insulin sensitivity.