I just read an article in the October 2020 Harvard Magazine that’s an excerpt from a terrific new book by Daniel Lieberman called Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding (Pantheon Books). The article is terrific, and I thought you might be interested in a brief summary of the sections that I found most fascinating.
Everyone knows that regular physical activity slows the aging process and helps prolong life. As Lieberman says, “I doubt anyone was astounded when Hippocrates wrote 2,500 years ago that ‘Eating alone will not make a man well: he must also take exercise.’ ” *
One section of the book describes two different intriguing research studies. In 1966, a team of physiologists decided to compare the effects of sedentariness versus exercise on health by paying five healthy 20 year olds to spend three weeks in bed, followed by an intensive eight week exercise program. The bed rest was ruinous. When they were finally allowed to arise from their beds, the volunteers’ bodies resembled 40 year olds by many metrics: they were fatter, had higher blood pressure, higher cholesterol levels, less muscle mass, and lower fitness. The eight ensuing weeks of exercise, however, not only reversed the deterioration but in some cases led to net improvements. The take-home message was simple: “Humans were meant to move.”
All that might sound obvious; but read on; there’s more.
To evaluate how aging affects the effects of inactivity, the researchers had the bright idea of re-studying the same volunteers 30 years later.
Three decades of typical American lifestyles had not been kind not the original volunteers: they had each gains about 50 pounds, had higher blood pressure and weaker hearts, and were less fit and healthy in numerous ways. But they agreed to be studied once more as they tried to undo the consequences of 30 sedentary years with a six month program of walking, cycling, and jogging. Fortunately, this second late-in-life exercise intervention helped the volunteers lose about 10 pounds, and most astoundingly, largely reversed their decline in cardiovascular fitness. After six months of moderate exercise, the average volunteers’s blood pressure, resting heart rate, and cardiac output returned to his 20 year old level.
Lieberman goes on to eloquently explain why, physiologically, exercise is so effective in slowing down the aging process, but the point I found so exciting is that it is never too late to start moving again.
Even for people that have been sedentary for decades, it’s never too late!
*Everything in italics is a direct quote from: