The body likes fat. It likes to be fat. It rewards you for doing things that make you fat, like sleeping and eating. The body likes muscle and bone, but to a much lesser degree. Why? Fat serves as a calorie reserve for hard times, which were a lot of times when we were evolving. Fat gets you through famine. Fat is also easy to maintain. You don’t need a lot of extra calories to support those tissues. They are metabolically cheap. Fat is like an extra gas tank that doesn’t take too much energy to haul around. Muscle and bone are a calorie drain. They are expensive tissues to maintain, sucking up calories even when you are sleeping. This is one of the reasons people with a lot of muscle find it easier to keep the weight off. They draw more calories even while asleep. The body’s survival strategy has always been to trim down muscle and bone to only what you need on a day to day basis. If you don’t prove to the body that you need them, they get reduced because they cost too much in calories to maintain. Muscle does not turn into fat, but muscle can thin out, and fat can fat in.

When a person exercises they expend energy in the form of calories but they also put a strain on the muscle and bone. Body tissues are piezoelectric. That means when you put a strain on body tissues they generate an electric field. This electric field signals the cells to build more muscle and bone. As you exercise you build muscle and strengthen bone internally. If you stop, there is no more electric field and the cells stop putting on muscle and bone. Muscle and bone eventually reduce to whatever you need to get through the day. You have to exercise twice a week to maintain what you have, more if you want to build up. Muscle and bone don’t fade away to nothing because we are still exercising somewhat by dragging our bodies across the surface of the planet. Where there is gravity there is resistance. The body reinforces itself to resist strain exerted on it. The more the strain, the more the reinforcement. This x ray of the foot reveals the internal structure of the bones.

If bones were solid bone they would be stronger – and three times heavier. That’s a lot to drag around. Instead the bones are mostly hollow with fine filaments inside to reinforce them. The filaments are aligned in the best way to resist stress on the bone. Note that most of the filaments in the calcaneous (heel bone) are running parallel from the heel to the ankle, matching the lines of force on the foot when the heel strikes the ground. Even as you read this there are groups of bone cells eating away unnecessary filaments and other groups building new filaments to resist stress more efficiently. The whole skeleton is replaced every two years or so. Its unchanging appearance is but an illusion.

The astronauts don’t have this resistance and their bodies suffer for it.  Their muscles and bones start to weaken after about three days. Who needs bones in space? Despite exercising a lot most of them end up with severe osteoporosis. When they come back to earth they often have to be carried off the space capsule on a gurney. Back on earth their bodies recover, but not completely. Going to Mars sounds like fun, but unless somebody comes up with artificial gravity like the Starship Enterprise,

we aren’t going anywhere. In the year or more in space it would take to get to Mars an astronaut would turn to jello. NASA has all sorts of strategies for this problem. They have resistance equipment on the space station but it’s not enough.  Nothing beats dealing with gravity 24/7. (Those strap on electric stim machines they sell in the TV guide so you can “exercise” in the Barcalounger while eating nachos don’t work either.)

The body likes exercise somewhat. Muscle and bone is good for some things; you could run out to the candy store for example (or away from a predator). The body rewards us for exercise with endorphins and serotonin, more feel good neurotransmitters, but you have to get going. Like most people, I never want to exercise, but I know that about five minutes into it my blood is up and then it’s good, or at least ok. I always feel better afterwards. You do have to get over that initial hump though. It also takes a certain amount of discipline. Like a diet, you need to make it an integral part of your routine.  Diet and exercise are lifelong. That being the case, try to find something that you like. I like nature so for me it’s swimming, biking, hiking, and skating. Some people like dancing, some are attracted to martial arts.

If you are social, take classes or find a workout partner. Keep trying different things until you find what works for you. It doesn’t have to be huge. A twenty minute walk at a good pace three times a week does wonders. Even a little exercise, if done on a regular basis will have real effects.

The piezoelectric effect mentioned earlier is found in many materials including collagen, a major structural protein of the body. The Body Electric, by Dr. Robert Becker and Gary Selden is an excellent book for all the wonderful things electricity does in your body.