[1] https://en.wikipedia.org/wiki/Persistence_hunting

    - Adopt a Paleolithic diet as much as possible: plenty of fruit,
      fish, vegetables, nuts, and meat while avoiding most forms of
      food not in existence in paleolithic time. It implies avoiding
      all processed food, and in particular junk food and food with a
      high glycemic load, such as sweets and cultivated crops like
      potatoes and cereal grains (in particular wheat).
    - Exercise frequently, but with a variety of durations and
      intensities (including rest periods) rather than doing always
      the same, extended routines in a gym or while jogging.
    - Perform a variety of complex "natural movements" (e.g. walking,
      running, jumping, crawling, climbing, carrying, throwing,
      swimming) that use the whole body rather than artificially
      constrained exercises that focus on specific muscles (like those
      afforded by most gym equipment).
    - Maximize contact with nature, e.g. by keeping plants, gardening,
      working with animals, hiking in the woods, or climbing trees (as
      also proposed by the biophilia philosophy).
    - Use a minimum of clothes and don't wear shoes: exposure to heat,
      cold, pressure, and other natural forces strengthens rather than
      weakens the body.
    - Expose yourself regularly to the sun or at least to natural
      light, to get sufficient vitamin D and prevent depression.
    - Try to sleep at least 8 hours a day, preferably in line with
      natural day-night rhythms (though people in pre-industrial
      societies do not sleep in contiguous blocks - see anthropology
      of sleep and segmented sleep).
    - Spend sufficient time relaxing, playing, and just "being in the
      present", without worrying about later.
    - Reduce overall levels of stress; avoid overworking in favor of
      downshifting and simple living.
    - Allow contact with dirt: soil contains plenty of beneficial
      bacteria that strengthen immunity. Eat fermented foods like
      sauerkraut, kim chi, kombucha, etc. Lifelong exposure to a
      variety of microbes may actually be necessary to prevent
      allergies and autoimmune diseases, as proposed by the hygiene
      hypothesis.
    - Rear children the way hunter-gatherers do: extended
      breast-feeding, carrying of babies on the body, co-sleeping,
      while allowing older children to play and explore
      autonomously.
    - Sit with legs level with rear end (essentially, in the squatting
      position), as people in indigenous tribes do.
    - Socialize and interact closely with a small group of real
      friends, instead of staying alone or "networking" with thousands
      of superficial acquaintances.

    - Die with 22 years from measles.

Not everybody accepts this though. Especially about point 2 and 3 I've had discussions, almost religious fights sometimes. People sometimes get offended when I question if just going to the gym and train a couple of standard groups or just jogging are sufficient exercises. They might be, just from the point of 'getting enough exercise', but I somehow believe it is better for your body in general to have way more types of movement trained, like the third point says. Not sure if this is backed up by research but it just seems logical to me? Another impression I have: the body of a person doing all kinds of sports always looks way more natural and healthy to me than persons doing only one or two sports where not all muscle groups are trained.

I'm wondering whether our ancestors did stretching exercises. I could imagine that the occasional yawn/stretch and a variety of different movements is sufficient to avoid contracture.