In-flight exercise

Although Apollo occurred in the first decade of manned space flight, doctors had already begun to test the body’s reaction to weightlessness during the Gemini programme and had noticed how muscle tone and bone mass were lost after only a few days. Bxcrcisc was believed to be the key to mitigating these effects but this was next to impossible in the cramped confines of a Gemini spacecraft – the exerciser was an elasticated strap, and the astronaut would loop one end around a foot and then pull against the tension. The greater volume afforded by an Apollo cabin permitted some limited exercise, especially when the couches were folded away. Every Apollo flight therefore carried an ‘Exer-genic’ or ‘Exergym’ exerciser, a commercial gadget consisting of a rope with handles that passed through a cylinder. The resistance to pulling the rope could be adjusted.

’’We all did a little bit of exercise almost every day." said Armstrong after his flight. "We used either isometrics or callisthenics in place, or the Exer-genie. It got a little hot and stored a lot of heat, but it was acceptable.’’

Collins elaborated on how their little gadget was dealing with the heat from friction. ’If you got a good workout on the Exer-gcnie, it got so hot that you couldn’t really touch it.”

As military test pilots for the most part, these men tended to take their exercise seriously in life outside NASA. Collins did daily runs, and Scott and Irwin often played handball. Armstrong was the exception when it came to exercising for its owm sake. As strong, fit individuals, they felt the need to exercise hard, even using the spacecraft’s structure, as the Apollo 12 crew related. "The thing we had for exercise,” said Gordon, "other than just moving around using the struts and the flat areas in the LEB for doing pushups and armpulls or whatever you wanted to do. is the Exergym. We all used it on the way out a couple of times a day for maybe a half hour each time. I didn’t use it at all coming back. Л1 didn’t use it coming back because the Exergym rope was frayed. Pete was using it on the wray back when he noticed that fibres were coming loose. So we elected not to use the exerciser at all on the way back.”

Surface crews found that the demands of working on the lunar surface was a hard exercise in itself. The CMPs. on the other hand, needed as much extra workout time as they could get, as Worden did on Apollo 15. "The Exergym is good for keeping some muscle tone,” he said after the flight, "but I found that there was just no way I could get a heart rate established and keep it going. I finally decided on a combination of two exercises. I used the Exergym a little bit. just to keep my shoulders and arms loned, and I ran in place. I took the centre couch out and flailed away with my legs, just like running in place as a matter of fact.’’

Crews regularly wore biomedical sensors on their skin that allowed the Surgeon in mission control to monitor their normal heart rate and breathing, and also while they were exercising. "I didn’t say anything to the ground.” continued Worden, ‘but the doctors watching the biomeds called up and said, ’Hey. you must be exercising. We can see your heart rate going up.’ And they kept me advised of what my heart rate was. It worked out very nicely. I thought, because they could tell you that you’re up to 130. going up to 140 (beats per minute). Then 1 would exercise a little bit harder, and true, even though I wasn’t exerting any pressure on anything, just moving the mass of your legs around really gets your heart going. As a matter of fact, I thought I’d strained some muscles that I had never used before because I was just free wheeling my legs and wasn’t exerting any pressure on anything. I found out that with the centre couch out, there’s just almost the right amount of room. In fact, the same thing could be done up in the tunnel area. You don’t need a whole lot of space.”

Irwin added, "We strained against the struts, against the bulkhead, and against the straps. This was kind of an isometric form of exercise. I think it’s almost as good as the Exergym.”

Ken Mattingly was not a huge fan of the exercise they had from a practical standpoint. “I just can’t believe that the amount of exercise 1 had justified 30 minutes [of my time],” he said after Apollo 16. ‘T really think I’d have been just as well off to just forget the whole thing.”

When it came to the CSM, Mattingly was regarded as an expert and he felt that the spacecraft’s environmental control system (ECS) might not handle the extra heat of someone who was really working out: “If you go out there and work up a sweat, really do exercise like you ought to. the ECS will not handle that kind of a load. The ECS is marginal. It’s designed for three marshmallows laying there. It isn’t designed for you to go out and do any exercise. The other thing I worried about was lying there and banging into things, because you can’t do any reasonable exercise and maintain your body position."

Sometimes crewmen exercised so vigorously that the entire spacecraft felt it. "Bob, this is Jack," called Schmitt to Bob Overmyer at the Capcom position. "I’m going to try to get a little exercise. I’d be interested to know how high I can get my heart rate just fooling around up here."

"Okay, we’ll keep you posted. Jack."

As Schmitt started exercising. Cernan noticed that the CSM’s barbecue roll was deviating. "I just figured out what happened on my PTC. here.” he told Overmyer. "With his exercises. Jack is shaking all of America in all three axes."

"Roger. He finally got to 115 on the heart rate," said Overmyer.

"Yes, the rate needles are bouncing back and forth a half a degree," laughed Schmitt as he watched his movements show on the FDAI needles that indicated rate of rotation.

Even EECOM. watching the spacecraft’s tanks, could see the effects.

17, we’ve got a serious one here.” joked Overmyer. "You might be interested. ЛИ that exercise banging around in there has destratified tank three 02. so it stirred it all up good.” The movement of the spacecraft had achieved the same effect that an internal fan had prior to Apollo 13’s explosion. It had disturbed the unwanted separation of density layers in the tank.

”Yes, glad we brought him along then." returned Schmitt’s colleagues. "We found some use for him.”