Which mode of exercise is NOT typically associated with improving cardiorespiratory fitness?

Weightlifting is not typically associated with improving cardiorespiratory fitness because it primarily focuses on building muscular strength and endurance rather than enhancing cardiovascular endurance. Weightlifting involves short bursts of intense effort, which may elevate heart rate temporarily, but it does not maintain a sustained increase in heart rate over time like aerobic exercises do.

In contrast, activities such as swimming, running, and circuit training usually involve continuous movement that keeps the heart rate elevated, thereby promoting better cardiovascular health. These exercises effectively improve the body's ability to transport and utilize oxygen, an essential aspect of cardiorespiratory fitness. While circuit training can include both strength and cardio elements, it's typically designed to minimize rest between exercises, improving heart rate and overall cardiorespiratory endurance. Therefore, weightlifting is less effective in this context compared to traditional aerobic activities.