Doing regular exercise for 12 weeks helped improve heart and lung fitness in obese black South African women, as measured by their ability to use oxygen during exercise. This finding is from the...

After a tough weight session, women tend to breathe harder during their cardio workout than after an easy weight session or no weights, but men don’t show this difference as clearly.

Doing short bursts of intense exercise for 12 weeks doesn't improve the maximum oxygen your body can use during exercise in people with excess body fat, even though they can exercise longer before getting tired.

After 10 months of high-intensity circuit training, sedentary overweight women experienced a 27% increase in aerobic capacity and muscle strength, and about half of those gains remained after stopping training for 5 months.

In obese Black South African women aged 20–35 with a BMI of 30–40 kg/m², a 12-week exercise program done four times per week at high intensity increases the body's ability to burn fat during steady exercise and improves maximum oxygen uptake.

Both short, intense sprints and steady, moderate workouts boost teenage boys' stamina just as much after six weeks — either way, their bodies get better at using oxygen.