Sleeping position is indeed an important aspect of overall health and recovery. As discussed with Jeff Cavaliere on the podcast, sleeping on your stomach is generally not recommended due to the excessive extension of the lumbar spine and the awkward positioning of your hands and neck.
Sleeping on your side can be beneficial, especially for those with conditions like sleep apnea, but it's important to avoid pulling your knees up towards your chest, as this can lead to prolonged hip flexion.
Sleeping on your back can be a good option, but be mindful of your feet. If your sheets are too tight at the end of the bed, it can lead to prolonged plantar flexion, which can shorten your calves over time.
Lastly, I'm a big believer in nasal breathing during sleep, which can be trained using a simple piece of medical tape. Remember, the goal is to find a sleep position that is least abrasive to your body while still ensuring a good night's sleep.