Deliberately entering physiological activation and then cognitively calming the mind can raise one's stress threshold and capacity.

“And there's also a way in which you can use things like cold showers, or if you exercise and you bring your heart rate up very high, you kind of go into that high-intensity realm where your heart is beating a little bit harder than you're comfortable with and that you're just you feel, some people think it's lactic acid. No one can agree on this what the burn is, whether or not it's lactic acids or it's buildup of hydrogen or whatever. I don't want to get into that, but we're all familiar with the intense feeling of your muscles kind of burning because you're working very hard physically. The key in those moments is to learn to relax the mind while the body is very activated.”