Is too much cardio bad for women over 40?

Nikkiey is clear that your heart is a muscle that needs work, and cardio is good for endurance and overall health. The trouble is volume without support. On Ep. 228 she explains that lots of cardio without the nutrition to back it up puts your body under stress and raises cortisol, which can lead to muscle loss. That is why months of boot camps can leave you with nothing to show for it. On Ep. 294 she adds that your body adapts: the more cardio you do, the more efficient it gets, burning fewer calories for the same work. On Ep. 402 she points out that cardio burns calories mainly while you're doing it and doesn't build the muscle that creates definition.

She also notes that other things, including hormonal changes, can cause these same signs. Her advice is not to write it off as aging. Get checked, advocate for yourself, and work with your doctor.

The fix is order, not more effort. On Ep. 228 Nikkiey puts nutrition first, weights second and cardio third, with cardio as the cherry on top: 10K steps a day, a spin class, some HIIT, or Orange Theory once or twice a week if you enjoy it. On Ep. 10 she describes doing two endurance days a week with the rest strength training, and suggests shorter, more intense sessions over excessive cardio, without overdoing HIIT either. Fuel properly, prioritize sleep and recovery, and keep your strength training progressive. If you've been grinding on the treadmill with nothing changing, it's the plan, not you.