Stretching

 I have been doing full splits almost every time I work out since 1990. Here's a picture of me warming up for the 2018 Pacific North West Warrior Tipon Tipon gathering:

If you want to be able to do this when you are almost 50 like me, pay attention: 

1. Clean living ages well - smoking, drinking, drugs etc. do nothing for you that you can't get from fruit, while wasting your money. 
2. Stretch every day for 10 minutes. 
3. There are two very specific stretches that I have found the most useful, which are Axe Kick Stretches (a dynamic stretch) and the splits (a static stretch.) Of the two, the Axe Kick Stretch is easier and more important, and it is a decent warm-up exercise:

But the more coveted stretch is the splits, which is probably a better cool down exercise for you than a warm up exercise. I have just about much experience doing the splits as anyone else alive on Earth, but I recently found a YouTube video that even helped ME do splits with less pain and effort: