I have learnt my lesson and concluded that the combination of:

• getting (half)naked sunbath for 30 minutes twice a week
• exercising
• proper sleep with unbroken 90-100 minute cycle phases (not waking up between a cycle, no erratic shitty alarms)
• no nocturnal peeing (do not overload with water before sleeping, pee before you sleep)

is the ultimate formula to a healthy, active and long lasting life.

Add a 10-15 minute power nap during midday/early evening and you are golden.