Endurance athletes typically spend about 70% of their training time at low intensity, which is crucial for improving VO2 max. The choice of exercise modality—whether running, cycling, or even unconventional options like sled dragging—can vary, but the key lies in the intensity and the specific demands placed on the muscles. New exercisers should be cautious with high-impact activities to avoid soreness, while experienced athletes can freely mix different forms of training for optimal results.