For me it’s bodyweight fitness (which is olympic gymnastics for newbies), following the recommended routine from the reddit /r/bodyweightfitness community, plus exercise bike every day.

Used to do weight training, the chance of injury becomes higher as you age. Also, as you add muscle mass and more training, you will need much more time to recover. Also always watch for overtraining symptoms.

Our body is the most precious thing we will ever encounter, or possess in life.