Interview with Chris Cassidy

From being curled up in the capsule heading to the International Space Station (ISS) at record speeds and feeling like a cannonball, to orbiting the earth 2,656 times or 70 million miles, and back down, and now to conquering a demanding 140.6 mile Triathlon in Kona. It’s Hawaii, tropical, vacation paradise – How hard could it be, right? Wrong! It is only for the toughest and bravest of heart. And Chris Cassidy has what it takes.

Chris Cassidy is a NASA astronaut and Navy SEAL. He was the 500th person in space when he went on the STS-127 mission July 15-31, 2009. Chris went up as a flight engineer for expedition 35/36 launched aboard Soyuz TMA-08M. He was in space at the ISS between March 28-September 10, 2013.

Just what were all the effects of gravity-free?


We take our fluid balance here on earth for granted. Once Chris got into space his body thought that he had too much fluid. His heart had to accommodate. He had to pee a lot. His face was puffy. It took weeks to adjust. He also had a stuffy nose for a month. And once he adjusted and his body balanced out, he had a lot less fluid.

Before Chris left for his return trip to earth he drank a lot, or as he said, he ‘pounded lots of fluids’. He also took salt tablets in order to retain more fluids. Then once he landed on the earth he was given an IV of fluids.

Not everything remained completely in balance up at the ISS though, and we will get to that as we go along here…


As far as VO2 max, his oxygen level, was concerned, Chris remained without change. Therefore he stayed fit aerobically. With lifting strength Chris actually came back stronger than before he left for the International Space Station (ISS). Now, this would not seem possible, right?! At first glance, I would agree. However, when you have 2 hours a day dedicated to exercise and have the backing of years of research from NASA and top notch people planning and guiding your workouts, then it is really no surprise.

The workout times were all scheduled in advance since there was obviously only one of each piece of equipment, which had to be shared among all members of the crew. The computer housed all the schedules, which were made by the teams on earth. It was very important for each crew member to start and stop their workouts on time since every single thing on the ISS is part of a finely tuned machine and if any one thing is off schedule, then this can throw everything else off. That being said, any time humans and luck are involved, things happen and so you need to adjust accordingly.

Just what did the 2 hours of workout time consist of up at the ISS?

  • ½ Hour was for Cardio – either Treadmill or the Bicycle
  • 1 Hour was for Weight Lifting: Squats, Dead Lifts, Bench Press, Shoulders, Hips, Gluts, Legs
  • ½ Hour – The final ½ Hour was for getting dressed and preparing and taking down the equipment, etc.

Some members of the ISS crew were more intense with their workouts than others, just as they would be on planet earth. Chris said that he personally was demanding with the intensity of his workouts. He said that it was a time that was good to focus on the exercises, and he also knew that he needed to do it to maintain his muscle mass, bone density, etc. In addition, it was a good stress reliever for him. It is not like he could just go outside for a run whenever he felt like it, or even a walk for that matter. And of course, the astronauts never wanted to make a mistake on any experiments or procedures while there. Under those circumstances, exercise was a good antidote to the stress for Chris.

If time was not a factor, then Chris said that he could have worked out more sometimes. However, there was no additional down time for further exercise.


The other thing that is closely related with the workouts is sleep. On the ISS sleep was scheduled from 10-6 every day/night. In addition, there was a 2-hour pre-sleep period and a 2-hour post-sleep period. The sleep time was sacred, as it should be for everyone here on earth as well. Sleep is restorative and a time when muscles and systems are recovering for the following day. When we do not allow enough time, we create dysfunction and inflammation and problems ensue. Unfortunately, sleep cannot be stored up.

Chris did well with sleep for the most part. He had to get used to having no pillow, which was strange. He was in a sleeping bag that was tied to the wall. He would get hot though and would unzip the bag sometimes. One time he unzipped the bag a little. Apparently, he floated out of the bag and flipped around and ended up being totally disoriented. Chris woke up and did not know where he was – that was quite a night and he did not want to repeat that scenario!

Chris’s bone density remained the same except for a small change, approximately less than ½%, which dropped in his heel and hip. This may have been due to his lack of walking with gravity.


The treadmill was Chris’s preferred method of cardiovascular exercise. Due to the lack of gravity he had to click in with a bungee cord and could adjust the amount of his body weight with a harness that pulled down from his shoulders as he walked or ran. The issue was that it felt somewhat like having a backpack on and even though the weight came through the hips, the majority of the weight was in the upper half rather than the lower half of the body as it usually is when we are walking and running on earth. Chris did a mixture of varying the percentage of his body weight and his speed.  He would wear the harness with the backpack and have approximately 70% body weight for walking, although he stated that the weighted harness was somewhat uncomfortable. For running he would wear the harness alone and be around 30% body weight. He varied his speed with the number of heel strikes for both.


Chris was surprised at how difficult the bike was initially. Before he was in space, he had done a series of protocols on a stationary bike and determined his VO2max. From his last VO2max his team prepared an exercise prescription for him to follow in space at the ISS. He had specific guidelines with a peak wattage that he was supposed to achieve. This had been predetermined from the testing that had been done in advance of his launch to the ISS.

The bike on the space station was not a regular bike as you would normally imagine. It was a box with pedals. There was no need for the person to sit due to the lack of gravity. They would just have their hands on either side. Once Chris was up in space he found that he needed to stop during his biking almost 15-17 times from sheer exhaustion. This was only 2-3 days after he got to the ISS. He could not understand how he could have lost his strength and endurance so quickly as to require 15-17 rest periods when biking. Chris spoke with his team at NASA and the fact was that up in space it is just the pedals and just the muscles of the legs working, namely, the quads and hamstrings pushing and pulling. There is no weight of the leg pushing down to assist. There is no assistance from the hands or the core, which usually adds a lot towards the overall workout.

Chris said that it took almost 2 months for him to get to a point where he felt adjusted to the biking. The remaining 4 of the 6 months were then fairly steady as far as the biking was concerned.

His muscles and body had adjusted to this new way of bicycling, which worked the quadriceps and hamstrings more, but possibly worked the core less.

Speaking of core, what happens with balance on and off the space station? Obviously, balance is not an issue when on the ISS. With no gravity, the body is taken care of in space in every direction. One does not need to worry about falling. Is there even such a thing as falling in space?


I asked Chris what was the most difficult thing to manage once he returned, and he definitively said BALANCE. It took a long time to get it back to within functional limits, 3 weeks, although the bulk of it did return within the first week.

When Chris first came out of the capsule, approximately 1 hour after touchdown, he was immediately put into a chair in a reclined position. For his first few steps he had other people spotting him. He was wobbly, but he was able to walk.

Then he and the other astronauts went through some testing.

  • First, he had to stand for 10 seconds.
  • Second, he had to lie on his stomach for 1 minute, then stand for 3 minutes; this was hard according to Chris. He said that he could feel his back, bottom, and stomach muscles firing, but they were not in synch and did not feel efficient at all. The muscle memory was not there yet. For me, I would think of it like the 5 year olds playing soccer – they all run around and have the muscle power within them, but they do not know how to put it all together. Compare this with division 1 college or professional soccer players who pass with finesse, have strong muscles and use these muscles efficiently. That is where Chris was and will get back to soon.
  • Third, he was asked to cross his arms and walk heel to toe as one would with a sobriety check. This was impossible for him to do at that time.

Once the above-mentioned testing was completed, then he took a 2 hour helicopter flight and had an IV and felt OK after that. Following an airplane flight to Houston and 24 hours later, Chris felt pretty much OK and was within normal to walk short distances. However, he did say that he would grab things to stabilize himself.

Chris was very pleased that he was fortunate enough to have 45 days of physical therapy for 2 hours a day once he returned. For the first week the focus was balance related and agility activities.

For example, he worked on the following:

  • Balance
  • Stabilization
  • Agility – Cones, ZigZag, Wiggly Ball &Platform, Bosu

Chris felt that he was approximately 85% to normal by the end of the 1st week. And by the last 2 weeks he felt that he really did not need it, although it was nice to be able to continue to review it.


For 2 months Chris felt that his stamina was not there. The interesting thing is that the data, the numbers state that his endurance should be fine. He talked with others who had returned from the ISS and they apparently felt the same way – their endurance just was not there right away.

This makes sense to me since there is specific endurance training. Think of training in the pool and then trying to adapt that to running or some other endurance sport. It takes time to adapt to that specific sport.


So, speaking of endurance, how did the Ironman come to fruition?

While Chris was on the ISS he and Luca Parmitano sent an email to the Ironman World Headquarters in Tampa asking about the possibility of doing a triathlon once they returned from space. Luca is an Italian astronaut in the European Astronaut Corps (ESA) who was on the ISS during the same time as Chris.

Luca had a neighbor who did Ironman triathlons and Chris was interested in doing one as well. In February/March 2014 Chris found out that he and Luca would be doing the Kona Ironman Triathlon as TeamAstro. He had approximately 8 months to really train for the race. Chris had done sprint triathlons previously, but even that had been a couple of years. In the time since then, Chris spent 6 months in space without any gravity. He returned in September 2013. Despite this, Chris did manage to get one half Ironman triathlon in for training during the summer 2014 before Kona. It felt good, but he knew that Kona and the full Ironman and the elements would be a different story.

For Chris, the overall distance of the Ironman Triathlon did not feel too bad. That may have had to do with the race day excitement or his preparation or a combination thereof. Before the start of the race the atmosphere is almost electric and athletes literally feed off the energy of the crowd. You can feel the buzz. For some athletes it is their profession, this is what they do and who they are. For the majority, this is something that they do because they want to conquer a bigger challenge. It is like going into battle for these athletes. For Chris, it felt in some ways like another mission, only this one was on earth – and he would definitely be fighting gravity every step of the way. But for all athletes regardless of their age or reason for racing, I think that they would all agree that they never felt more alive than at the start of the race. Each and every athlete was ready to discover what she or he was made of and how well s/he could do against the elements in Kona. Now was their time and their moment to shine!


Chris found the swim to be hard with the mass start. He had people touching and kicking him the entire 1 ¼ miles out and 1 ¼ miles back in the choppy waters with growing swells that just got more and more difficult to navigate. According to the race officials, there was an offshore storm that created the roughest conditions that the race had in years.


The wind was a factor as usual with the bike portion of the Triathlon. It was windier than usual and did blow people over on their bikes. Chris found the bike to be difficult due to the winds, but also because of the hills. He trained in Houston where there are no hills and therefore the hills in Kona were more than what he was used to riding in Houston.


Chris said the run was hard, but he was excited during the run and felt that it went by quickly, all 26.2 miles. He could hear people while he was running whereas he could not during the swim or bike. And he was able to High-5 people, both adults and children, during the run and this felt great and helped to motivate him and make the run go by fast.

Chris enjoyed doing the Kona Ironman Triathlon very much and finished in 10:15.11. This was below his personal goal of 11 hours. His time placed him at 555 overall. Pretty amazing for someone gravity free less than 1 year before the race!

As far as future Triathlons are concerned, Chris figures that he now has the gear, so he may as well do some more Triathlons – maybe some of the local ones in Texas for starters. He already misses the training that he was doing for Kona! Chris mentioned that there are even Triathlons that you can do for you and your dog – now that would be interesting!

Chris can now add Kona Ironman Triathlete to his long list of accomplishments, which includes NASA astronaut, Navy SEAL, visitor at ISS twice, father of 3, and more. He always has his sights set on something. There will likely be more races in his future, and he would like to head up into space again and maybe even visit the moon, and who knows where else because…the sky’s no limit for Chris Cassidy. He is One Who’s Won, and Chris will continue to do so.

Thanks for our One on Won – Dr. Mary Ann