Harold J. Reilly, owner of a New York gym during the 1930s and 40s, promoted the idea of using children as exercise equipment. Pick them up and swing them around, he urged parents, as one would a dumbbell or kettlebell.
The advantage of using kids as dumbbells, he pointed out, was that as they grow older their weight will increase, thereby naturally helping the parents to develop their strength.
It's an intriguing idea, although a set of dumbbells is a lot
cheaper than having children. And won't break if you drop them.
Minneapolis Star - May 31, 1942
"Reilly recommends that parents (or grandparents) work out by swinging their youngsters around from childhood. Says it helps both out."
NY Daily News - May 2, 1948
Pittsburgh Sun-Telegraph - Aug 3, 1941
Text from the Pittsburgh Sun-Telegraph - Aug 3, 1941:
Some years ago Mr. Reilly was thumbing through a volume of Greek mythology when he read how Hercules, as a boy, started lifting a small calf every day. As the calf grew, so did Hercules' strength so that when it became a full-grown bull Hercules could still lift it.
Mr. Reilly thought that the story could be given a modern twist and proceeded to do so. He became "Hercules" and his infant son and daughter the small "calves."...
For years he carried out this theory conscientiously with his own children and it worked so well that it prompted him to write a recent book about physical culture in which he advocates that both fathers and children will benefit greatly if the former raise the latter as dumb-bells.
"I'm not suggesting that you bring a bull calf into the house and go to work on it. After all you're not Hercules," Mr. Reilly points out in "The Secret of Better Health," published by Carlyle House, "But you can work out the same idea by starting to exercise with your pride and joy when he's only a year old, and keeping it up until he's ten, 15 or even 20. The child will benefit, and so will you...
"You may start when your child is an infant," says Mr. Reilly. "But as babies are delicate, don't begin by wrestling with him. Just manipulate the baby's arms and legs. Wiggle them around, being careful not to twist harshly... Then as the child begins to walk, you can swing him by the arms."...
"From three to six, you can become a little more strenuous. Pick the child up and swing him around, holding him by the arms. Let him lie on his back and take his two hands in one of yours and his ankles in the other and swing him around that way, back and forth, sideways and between your legs as though he were a medicine ball...
Mr. Reilly says that the swinging-around game should be kept up during the six-to-nine period of the child's age. In addition he should be picked up by the ankles and walked around, wheelbarrow fashion...
"From nine to 15 keep up the same exercises, if you can, and begin to box and wrestle with him," says Mr. Reilly. "It is just as easy with a daughter, for a little girl is a natural tomboy. She doesn't begin to be a female until around 12 years when adolescence sets in. Then a certain amount of care is necessary. But until then, treat your daughter the same as your son."
Found a video of a guy using his kids as weights.