Integrating breath-hold exercises during workouts, such as on a bike or during a run, can improve CO2 tolerance.

“working on things like nasal breathing and even doing some breath hold work while doing training like there's no reason why you can't hold on an exhale or an inhale when you're actually working out now i wouldn't do that while lifting weights because blood pressure changes can be really impacted and you can actually drop yourself but you sit on a bike or you go for a run”