Fitness

We have plenty of studies that exercise improves sleep, both in people with regular sleep patterns and those struggling with insomnia.

This particular study, which concludes that yoga and tai chi are even better than most exercise, seems to be based on more limited data.

Rather than chase after the type of exercise that has the best results in a particular study, it's probably better to try for the type of exercise you're most likely to stick with on a regular basis, for better adherence to the general idea of regular exercise. Then get the general benefits of exercise, including improved sleep, that have been broadly proven with many studies.