Pushing the boundaries of human physical performance in space
On Sunday 24th April, UK astronaut and Blue Abyss supporter Major Tim Peake ran the London Marathon whilst on the International Space Station (ISS), 400 kilometers above 39,000 of his fellow athletes. Completing a time of three hours, 35 minutes and 21 seconds on behalf of the Princes Trust, Tim set a new Guinness World Record for the fastest Space marathon.
But what does it take to run a marathon in Space? Blue Abyss’ very own Space Life Scientist, Professor Simon Evetts, gives us the lowdown and Tim Peake spares a few moments to tell us how it went for him.
The biggest problem when running a marathon in Space is counteracting the effects of weightlessness. The astronaut must be anchored to the treadmill to stop him or her from floating away. In Tim’s case, this was by means of a weighted harness strapped around his waist and shoulders with chains connecting to a bungee system attached to the treadmill. Up to around 75% of body weight is normally applied in this manner. So, although astronauts have the advantage over conventional marathon runners of not carrying full body weight, because the loading is concentrated on the shoulders and waist, it can be very uncomfortable and can cause painful pressure sores.
“The run went better than expected,” Tim says. “I thought I'd stick to a steady 7.5mph, but when I got to 10 miles I realised I could run faster and found that the longer stride made it less painful on the shoulders. So I went to 8mph for a while and then to 8.6mph at the end. So my legs paid the price but my shoulders were grateful!”
Astronauts don't load weight on their feet like we do on Earth, so the tough skin on the soles of the feet becomes ‘baby soft’ after a few months. For this reason, it's possible for blisters to develop on the feet a little easier during a Space marathon.
Resistance exercise in Space provides muscles with the necessary stimulus to give astronauts' bones and muscles a good workout. This ensures that they don’t lose muscle mass and bone density, which happens around 7 times faster than it does on Earth when we don’t exercise. Generally, astronauts will train for around two hours every day to try to retain their pre-mission fitness, although it’s common for aerobic fitness to deteriorate after a few months in Space. As a consequence, a marathon might feel a little tougher!
Because food doesn’t settle or get digested in quite the same way in Space, timing when to eat before a Space race needs careful consideration. Balancing the need for fuel later in the race (once it’s digested) against feeling bloated and full early in the race isn’t easy.
In Space, colder, heavier air doesn’t drop and conversely, lighter, warmer air doesn’t rise. So convection currents are not possible which means that gases tend to remain static. Without a ventilation system to keep the air moving, carbon dioxide can build up around the astronaut’s head triggering a nasty headache.
Exercise generates perspiration, no matter where you are. Rather than falling to the ground, in Space sweat assembles in patches around the skin and needs to be wiped away, adding extra irritation for the Space athlete.
Astronauts’ ability to control body temperature is altered in Space. It appears that they become a little hotter, almost like having a mild fever, and after they exercise it can take a little longer to cool down.
Lastly, keeping motivated during a long race without the camaraderie of other competitors and a sea of spectators around you can be challenging.
Watching the live marathon on BBC the whole time was a huge encouragement – I had thought I would watch a movie (‘2001: A Space Odyssey’ was ready to go) or listen to my #Spacerocks playlist, but in fact it was extremely motivating watching the coverage of the event and hearing the stories of some of the 33,000 people taking part. In addition to that – I was able to compare my progress to the live event since I had the RunSocial app giving me an excellent view of the streets of London as I ran the marathon,” says Tim.
We’ve looked at the many challenges that face the Space athlete, but astronauts enjoy one major advantage over their counterparts on Earth. Once disconnected from the harness, weightlessness provides the perfect environment for recovery. Muscles completely relax and the body recovers from aches and pains much faster than it would on Earth. So after a race, astronauts can take the weight of their feet… literally!
And whilst Tim puts his feet up, he shares one last word with the Blue Abyss community, “Good luck with the final kick-off stages for Blue Abyss!”
Image credit: ESA – Major Tim Peake 28/04/2016
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