In my case, in my running 30 yrs ago, running TOO hard on my rest days was a killer, as Mr. Maffetone explains here. I got a HR monitor finally and this stopped my TOO hard of running, stopped my injuries, and I got faster... -- Not that others might help you but STAY with Mr. Maffetone and Coach Parry. Both have lived running and can help you.

There's guy, let's name him Gerald, who is 20 years old. He subtracted 20 from 180 and got to 160. Then he added 5 because he had been training consistently for 6 years. That gave him a maximal aerobic function heart rate of 165 bpm. Only trouble is, Gerald was tested in a lab with a VO2MAX protocol, and his maximal heart rate turned out to be 164. That formula isn't any better than most others. The only formula that I believe is worth it is the Karvonen formula, provided you know your true maximal and minimal heart rates. The rest is just trash. Or do I misunderstand those formulae?

Hey paul, could you say that this formula from phil is the training of zone 2 of mitochondria? Aerobic fat burning, anaerobic sugar, phil's formula is very good for training, I'm just waiting to buy a watch and chest strap.

Is it ok that i blast my cardio extra hard? I do like 180 heart beat for 40 minutes or so on a stairmaster and someone was saying oh thats too high of heart rate and thats for intervel training. I get in shape faster the harder I blast her so wtf? Is there really a max? Should i even care? Is the machine reading my heart rate wrong? I mean its easier than highscool wrestling whatever im doing so should be fine since I used to do that. This is my starting point by the way. I either never do cardio and look like im in shape, or I do this and get in better shape. Im basically an athlete. Im 41 years old.