Fifty years ago, there were no "rec" centers - if my recollection is correct. For me, there was the local YMCA.
The weight room and its users, alternately grunting and flexing in front of mirrors, were unfamiliar, except as a shortcut to the pool or the racquet courts. The weight-lifters with their overdeveloped upper bodies and spindly legs couldn't have outrun a toddler with a loaded diaper.
By the time of Arnold Schwarzenegger several decades later, there was better upper/
lower body balance and respectability. Pumping iron was almost a household term, but remained form over function. In academia, nothing stays the same, especially terminology - that's how most of us remain behind. "Pumping iron" now is referred to as "cyclical resistance training." Moreover, its health benefits are recognized as significant, especially in weight loss and in amelioration or prevention of Type 2 diabetes.
It is a given that there are no obese marathoners, whose Type 1 skeletal (and cardiac) muscle fibers, also known as slow-twitch, are trained to the max. In the last few years, Type 2 or fast-twitch fibers have been studied in mice and men. In mice, researchers at Boston University School of Medicine, led by Dr. Ken Walsh, alternately turned off and turned on the gene controlling Type 2 muscle growth. Fed the common fast-food, high-fat, high-sucrose diet, the mice became obese with Type 2 muscle shut off and lost weight with Type 2 fiber growth.
There were other benefits: improved blood-sugar levels and insulin regulation were observed, and these results now are being confirmed in humans. Type 2 fibers also may burn calories faster in their resting state than Type 1. There are some racial differences, and the effects may not be as prominent in women as in men. Consider the early astronauts and their weightless, zero-G environment. Their "inactivity" caused such bone wasting and calcium loss as to worry aerospace physicians about kidney stones and sudden incapacitation. Bed rest for weeks and months for ordinary humanoids is equally debilitating. The prescription for astronauts includes resistance training.
Nobody suggests a full-time or daily venue with the weights and mirrors. Endurance training (the Type 1 fibers) keeps us ahead of the toddler and is important for cardiovascular fitness. It is not to be discounted. There is evidence that the benefits of resistance exercise last for 48 to 72 hours. The true couch potato is the biggest loser - obesity, hypertension, diabetes (the metabolic syndrome) and heart disease.
One comment of Dr. Walsh's stunned me: "Beyond the age of 30, humans lose approximately six pounds of muscle mass per decade. Surprisingly, aging individuals predominantly lose Type 2 muscle." This comment begs the obvious question and its equally obvious answer. What replaces the lost muscle (and presumably bone)? Fat. Mirrors, anybody?
I'm anything but an exercise physiologist. For an exercise prescription, use common sense or an exercise physiologist. You'll find one of the latter on any street corner in Durango, standing between the orthopedist and the physical therapist. It's either them or a cardiologist.
Dr. Fraser Houston is a retired emergency room physician who worked at area hospitals after moving to Southwest Colorado from New Hampshire in 1990.