Astronaut conditioning research

I saw this in the New Scientist - How to survive the long haul in space - it is about how to tackle some of the health problems associated with being in space.

It turns out that maintaining the strength of muscle and bone is really important.....and is also a real challenge when weights are weightless.

In terms of High Intensity Interval Training (HIIT) there are a few interesting ideas being tried out:

Short bursts of high-intensity resistance training, at around 70 per cent of the muscles' maximum capacity for 15 minutes, twice a day, should help, says Fitts. A range of studies in animals and volunteers confined to bed rest suggest this will protect muscles better than long periods of low-intensity aerobic exercise. It may also guard against bone loss. Dan Bikle of the University of California, San Francisco, who has studied bone loss in rats whose hindquarters are suspended off the ground, recommends intense weight-bearing exercise for 1 second in 10, for a few minutes each day

What also caught my eye though was the idea of using resistance bands. They have been using what NASA call an Interim Resistive Exercise Device (IRED):

There has been a bit published on the studies which they have done with the device. Interestingly while it helped preserve muscle it did nothing for the bone density.

Scientists found that the only way they could reverse this process was by using exercises that deformed the bone cells (think of them squishing, like a tennis ball you’re standing on). This, they found, slowed bone mineral reabsorption (a natural process in the body that weakens bones) and increased bone density. They thought the iRED would accomplish this. But it didn’t work.
“The elastic bands simply didn’t provide enough resistance,” says Garcia. “And the resistance they did provide wasn’t consistent enough to affect the bone mass of the astronauts.”

That is from this interesting commentary which has a few key principles of the sort we might be familiar with here:

Rule 1: Use heavy weights (at least 80 percent of your max).
“In order to sufficiently work muscle and bone fiber to the point where the aging process is slowed,” says Spiering, “people can’t just run and play sports.” In space, the NASA astronauts experienced accelerated atrophy — even if they ran on treadmills. Heavy lifting — rather than static loading, as during a jog — was the only way, NASA scientists found, to deform the bone cells enough to grow cortical bone. To achieve this effect on Earth, Spiering found that resistance training — exercises such as squats, bench presses, and dead lifts — at 80 to 85 percent of the maximum amount you can lift is the optimum way to stop bone and muscle deterioration.

Rule 2: Slow down. Lifting weights isn’t nearly as critical as how you lower them.
The iRED revealed that the fluctuating resistance due to its elastic webbing limited eccentric forces — the resistance generated by lowering a weight — by 60 percent. Although iRED users were able to gain some muscle strength from the machine, their bone density decreased rapidly. Schneider assumed that the machine’s inability to generate eccentric force was the culprit. So in 2003 she put a group of men on a steady diet of exercises with free weights, which increase eccentric force when lowered slowly. (This theory had been out there before. In the early 2000s, many fitness buffs began clinging to an exercise program called Super Slow, which promised to increase metabolism and lower bad cholesterol. It seemed to work — though people weren’t sure why — and soon after many people replaced it with more functional training like CrossFit.) After 16 weeks, she tested the men’s bone mineral density and found that it had improved dramatically from their pre-program levels.

Rule 3: Drop the number of reps (keep the intensity high).
Earlier this year Scott Trappe, the director of the Human Performance Lab at Ball State University, in Muncie, Indiana, used NASA’s data from nine astronauts aboard the ISS to conduct and publish a study about weightlessness and exercise in the Journal of Applied Physiology. Using MRIs and biopsies to measure muscle fibers, he concluded that intense movements, like sprinting, jumping, and throwing (see the exercises at right), along with lifting heavy weights, resulted in better muscle size, a key element to protecting bones and thus keeping them from aging too quickly. The discovery wasn’t exactly surprising, but Trappe’s study did bust one misconception about the amount people exercise. “Most people think that more is better,” he says. “But our study showed that exercise should be done much less frequently than conventional wisdom suggests — but with much greater intensity.” Says Garcia: “The most recent space flight research indicates that doing six to eight reps — not the typical 10 — best maintains muscle function and strength.” In a recent study, Trappe found that elderly men who had been training three days a week, at 80 percent of their maximum loads, were able to maintain their muscle mass with just one high-intensity workout a week.

I don't know where I am going with this, but it is an interesting bunch of stuff to read. Train hard, less frequently, with slow negatives using heavy weights. Arthur Jones, John Little and Doug McGuff would be proud of NASA!

I'm not sure what it says about resistance bands though, if anything.