Take care of your body. Stretch. Warm up. 30 is the threshold where you start to really lose the ability to heal. You can injure yourself now and your body just won't heal back to 100%. Ever.
[0] https://www.healthline.com/nutrition/lysine-benefits
[1] https://www.amazon.com/Amazon-Elements-Complex-Vitamin-Veget...
What is important is being healthy enough to heal. That means you need to eat well, exercise regularly and give yourself time to heal if you have to.
Edit: to be clear the injuries are obtained through risky sporting activities not through general wear and tear and general exercise.
To clarify my point about healing, most people don’t give themselves time to heal properly at any age and end up with a compromised outcome.
Right... isn't that what they're saying happens if you don't exercise enough so proving their point?