Everybody wants to live longer, few actually understand how to structure their fitness and lifestyle to see meaningful and measurable improvements in key metrics efficiently and effectively. Each training interval should take you to 85% and above your maximum heart rate (use 220 - (your age) to approximate) and each recovery interval down to 50% and below. In my case, as a 27 year old, my max is estimated at 193bpm, so my working intervals need to be 164bpm+, and my recovery intervals need to be 96bpm- Quickest way to do this is through compound movements that use as much muscle mass in as little time as possible. Sprints are my favorite and very functional/evolutionarily consistent. Takes about 2-3 min to replenish enough creatine phosphate for you to approach your next set with similar or higher intensity. Creatine supplementation helps, I like thenocompany_ (not an ad) Do this on high recovery days, when your physiology is primed to derive as much of an adaptive response from ...