The more the body moves, the more it has to replace cells, when this happens faster than the body can expel, the body ages. As long as you never exercise to the point of feeling tired, your AOK, but if you experience that "Burn" effect, your also experiencing allot of acid created by the process of excessive exercising. Thats why I stopped it along time ago other than "PLAY" and use zero weights while playing and the only sweat I work up is while working in the sun too long. A few will take this a step further and believe you have X amount of breathes and the more you exercise the faster you burn your body up cell by cell, I am not sure about the breathe thing, but the YOGA experts sure try hard to reduce the amount of breathes taken in a days time.
I say do what you enjoy the most in life............
Henry Ford wrote that when you can sit, sit, when you can lie down, lie down... But he sure didn't believe his slaves should have that luxery!!
pH paper never lies... While fasting you know your done when the pH paper is 7 and the acid has stopped being expelled. Normally the acid is driven up and out the skin and this effect gives you new skin. So there are 2 possibilities here, either you don't have an acid condition or you are creating more than the body can deal with by means of too much exercise/work.
Most people believe in exercise and exercise is GREAT, but the human body does best with stretching exercises. The trampoline is a great exercise, but you need good guts to keep it all together and a good heart. The inversion machine is an excellant exercise that needs no work to do and to me the leg shaker machine replaces all known exercises, even yoga is not as good. Take a long hot bath, get out and do 15-30 minutes on a chi machine and then go to bed, it will do wonders and keeps the person from needing a chiropractor as often if ever.
What your doing is great because your having fun doing it. Why your body is not going alkaline aka reversing age can only be because your burning up more cells than you can eliminate is my best guess. An example: look at Jack LaLane, I seen him last about 5 years ago and he looked way over 100 years old in appearance, yet the guy is still superman because of his exercises, but this is not saving his life as the face never lies about pH.
I suggest you do as your doing always to the point of just having fun and NEVER seek the "burn", that burn while exercising is your calcium coming out of your bones to neutralize the acid and when you pee your bones down the drain faster than you make bone, we call that ageing.
Many Blessings,
MH