First, people that exercise more have cells that look younger than those that rarely exercise, according to a new study:
Telomeres cap the ends of chromosomes, the structures that carry genes. Every time a cell divides, the telomeres get shorter. When the telomeres get too short, the cell can no longer divide. Scientists believe that aging occurs as more and more cells reach the end of their telomeres and die — muscles weaken, skin wrinkles, eyesight and hearing fade, organs fail, and thinking clouds.
Spector and his colleagues analyzed the telomeres from white blood cells collected from 2,401 twins participating in a long-term health study, examining whether there was a relationship between the subjects’ telomere length and how much exercise they got in their spare time over a 10-year period.
“We’re using telomere length as a marker of our rate of biological aging,” Spector said.
The length of the twins’ telomeres was directly related to their activity levels, the researchers found. People who did a moderate amount of exercise — about 100 minutes a week of activity such as tennis, swimming or running — had telomeres that on average looked like those of someone about five or six years younger than those who did the least — about 16 minutes a week. Those who did the most — doing about three hours a week of moderate to vigorous activity– had telomeres that appeared to be about nine years younger than those who did the least.
And in a related note, it’s hard to get started exercising for a reason:
The substance that allows your muscles to contract is called adenosine triphosphate, or ATP. Your body has several ways to synthesize it using such materials as creatine, lactic acid, glycogen and a bunch of enzymes, all present in the body. A couple of those methods can be tapped quickly to support an increase in activity — when you pop up the stairs from the company lunchroom, for example, or run a sprint.
However, those initial energy sources can keep pace for only the first few minutes. After that, the body turns to its real energy powerhouse: aerobic glycolysis, a process in which glucose (the basic sugar that the body uses for fuel) is broken down with the aid of oxygen to produce ATP. It’s a very productive system, by some estimates yielding 30 or more molecules of ATP for each molecule of glucose. That’s why it can sustain all those crazy bouts on the elliptical, not to mention a marathon run.
But it takes time to stoke up. In the interim, we suffer.
“[The process] is physiological, but it becomes a psychological issue,” said Walt Thompson, a professor of kinesiology and health at Georgia State University in Atlanta. “The first half-mile [of a run] is like, ‘I am going to quit.’ . . . But I know exactly where I am going to feel better.”
Carla Sottovia, an exercise physiologist and assistant fitness director at the Cooper Fitness Center in Texas, said those first few minutes of exercise amount to a state of oxygen deprivation, with the body struggling to keep up with the suddenly increased demand, then finally reaching a steady, sustainable state.
It’s a feeling that can be particularly discouraging for beginners, mistaken as a sign of being out of shape (only partially true) instead of understood as a manageable transition into exercise.