The best workouts for improving cardiovascular endurance include activities that elevate the heart rate over sustained periods. Examples include running, cycling, swimming, and rowing. These aerobic exercises enhance the body’s ability to deliver oxygen to muscles, increasing efficiency during physical activity. High-Intensity Interval Training (HIIT) is also effective, as it alternates between intense bursts of exercise and rest or lower-intensity periods, further improving both aerobic and anaerobic fitness. Consistency in these workouts can lead to significant endurance gains.