Do Altitude Tents Really Work?? Setting the Stage to Answer a Tough Question….

25 Jul

The Theory of Altitude Tents:

The theory of the altitude tent is relatively simple.  Sleeping in a hypoxic ( which means less oxygen than the “normal” 21% oxygen content of “air”) tent attempts to simulate some of the beneficial physiological responses that are well-established for athletes living in real-world high altitude environments.  Although there are several mitochondrial and metabolic changes that contribute to the benefits of high altitude living, the primary adaptation that people are after is:

Increased Erythropoiesis (what the heck is that?…it really just means making more red blood cells)

             When there are lower oxygen levels circulating in your blood (as is the case at altitude because the air is “thinner” and there is relatively less of every atmospheric gas, including oxygen, as compared to sea level) your kidney actually detects this low oxygen level and releases a hormone called erythropoietin, or EPO.  EPO then circulates in your body and tells your bone marrow to start producing more red blood cells.  More red blood cells result in increased oxygen carrying capacity of blood, hence increasing the oxygen in your blood to maintain the balance that keeps the kidney happy.  This increase of oxygen in the blood also boosts performance in endurance-related sports because more oxygen to muscle means the muscle can do more work, experience less fatigue and have less lactic acid produced for a given amount of exercise.  More oxygen carrying also implies a higher VO2max for those who like buzz words.  This EPO hormone is the same hormone that has made many professional cyclists infamous- the only difference is the injectable one is made in a lab, but it is the same hormone.  Interestingly, the primary legitimate medical indication for EPO use is kidney failure for the reasons described above.  The question remains whether or not a simulated hypoxic tent environment actually replicates this same biological response seen at altitude?

Diagram of Erythropoiesis (making more red blood cells)


Hypoxic Vs. Hypobaric:

A very important distinction to make when assessing altitude tents is the difference between hypoxic and hypobaric.  In the real world, high altitude is a hypobaric state.  Hypobaric means that all atmospheric gases are “thinner” at higher altitudes and therefore less abundant.  While less oxygen is available at high altitude, 21% of the “air” is still oxygen. The way an altitude tent works is different.  An altitude tent works under a hypoxic environment instead of a hypobaric environment.  The air has the same “thickness” as the altitude at which the tent is set up.  The hypoxic tent environment replaces part of the percentage of the “air” that is oxygen with nitrogen.  Hypoxic (and normobaric) means you are breathing less than 21% oxygen but the air is still “thick” like at sea level.  Unlike real altitude, there are lots of gas molecules around in a tent, just a little more nitrogen and a little less oxygen than the normal breakdown of air. The hypoxic vs. hypobaric distinction becomes very important when we look at the potential limitations of altitude tents and reasons why some physiological responses may be different. 

Of note, “normal” air is about 78% nitrogen anyways so nitrogen is very abundant and it won’t hurt you to breathe a little more of it for anyone who may think breathing nitrogen sounds scary. 

Responders Vs. Non-Responders

The term “responder” is a commonly used term in the altitude tent literature. It simply means that some people experience benefits from the tent in similar ways to altitude, while others do not. No one quite knows why it works for some people and not others. It is probably multifactorial and very complex.  There has been a particular interest in studying the association of a particular enzyme genotype, call the angiotensin converting enzyme, in association to whether or not someone is a “responder.”  This angiotensin converting enzyme is just a fancy name for an enzyme in our bodies that contributes to blood pressure control and it is postulated that it also plays a role in how we adapt to altitude, although the mechanism for this theory is not understood.  People inherit different versions of the gene that is in charge of this enzyme and it might make a difference what version of the gene you have. In short, some people may respond while others do not and we don’t really know why, but different gene makeups probably play a significant role.

So do the tents work….???

Ah ha!  So I have done a review of the current published scientific literature on this topic and I will be posting my impressions very very shortly….stay tuned….


Next topic up…Does compression wear really do anything?? Or are you just being duped into buying some really expensive old man tube socks??




4 Jul

Check out this sweet article written on by the talented Sarah Wassner. The article highlights me and two other professional athletes who are following their passion for sport while maintaining professional careers…very cool!

Philly Triathlon- 4th place

28 Jun

This past weekend was the philly triathlon. This is one of the coolest race courses on the circuit. The swim is a point to point, the bike is a hilly 2 lap course right through the most beautiful parts of philly and the run is an easy, flat double loop that is mostly shaded…amazing!

I was happy with my race and effort. I defiantely need to perk up my swimming a bit though. I was about 40 seconds further down than I usually am (the lead girls got to draft off the men because we started together and that front pack cut the last buoy- bummer for me who stopped and redirected myself around that last buoy =( ) Starting a little further back after the swim was tough on this course because it is so turny and hilly that you can’t see anyone up the road. Nonetheless, I had a similar bike in terms of watts to last week – which means I was hammering the bike- and my run was better than last week I thought. The run was cool under the shade and temps were in the 70s- perfect for a fast day. The top 3 women broke the course record so it was evident that conditions were perfect. All in all a good day putting me second in the series now- I am definitely consistent if nothing else! My coach and I have some new things to try for swimming and time to go back and work on that now… There is always something to work on when you are doing 3 sports. Next race I will have Wes there too- which always seems to be a lucky charm for me!!

At the end of the day, I would highly recommend this race because of the unique and beautiful course, especially if you like hills!

Washington DC Race Report- 2nd Place

22 Jun

Maybe it is all about the bike?

So this weekend I came 2nd behind a formidable Alicia Kaye by 30 seconds even. I was really pleased with this result and even more pleased that I learned a ton about myself and about strategy. Greg has been telling me to hammer the bike but I am not quite sure I understood what that meant before this weekend. I’ve been swimming and biking a lot more in the past two weeks and it really paid off during the race. Unfortunately I still ended up swimming alone for most of the 1500m but I emerged only about 1 minute down from the leaders. Getting on the bike I was quite far back in about 15th place – this field seemed to be very heavy with super-swimmers and I passed only a few people in the first lap of the bike. Then I had this moment of revelation- about ¾ of the way into the first bike lap I thought to myself, “What if I tried to pretend this was a 40k TT all out with no run afterwards?? Maybe I should just see what happens?”

I have never really bonked on a run in triathlon before- I actually think this is my greatest strength. When it is hot or freezing or I drop my water bottle and have no water or lose my nutrition or it is terrible conditions- I can always hang on in the run while most of the field falls apart around me. This strength has caused me to probably over-perform in several races already (like 3rd at USAT elite nationals last year behind Laura Bennett and Sarah Groff in my first ever ITU race- of course I wasn’t at that level yet but it happened to be 95 degrees when we started the run….so the entire field came back to me) How can I leverage that strength in races when it is not 100 degrees out? I think drilling the bike may be the answer for me and a unique asset of my physiology? Or maybe this is what everyone does in Olympic distance racing and I just caught on for the first time last week..? Either way- it worked.

Anyways, so I took the risk and went really hard on the bike. Wes was there giving me split times away from the leaders every time I saw him and that was super helpful- he knew exactly what I needed and just kept telling me to keep hammering. Thanks Wes!!! Barry, Cathy and the young family were also there cheering me on which was incredible. I posted the fastest bike split by 30 seconds and put myself right behind the leaders going into the run. My run was probably 30-45 seconds slower than it has been but I still had the second fastest run split and I am waiting to train up my run until we get closer to big races later in the season. I still ended up way ahead of the game at the end of the day with an awesome result for me at this point- I didn’t bonk on the run and I finally learned how to utilize what I have known for a while is a strength in a race. I just can’t wait to put all the pieces together when the time comes…how exciting!! Having a great race and learning something that you can use in future races is the best feeling ever!!!

I think the take away point that everyone can use is: Try to identify your strengths. Maybe they are a little unconventional and a little more specific than, “I am a good swimmer.” Maybe they seem situational and difficult to leverage but then keep thinking about it and brainstorming creative ideas to use your strengths. It wasn’t obvious to me at first, but now I see it clearly. Just keep meditating on it and it will come to you eventually. Then you will know the most successful strategy for you…

A different kind of pro triathlete blog….

8 Jun

So every Pro Triathlete has to have a blog.  But I don’t really find the topics of what I eat for breakfast or my favorite summer smoothie recipe to be all that intriguing (although there is nothing wrong with those blogs of course- I am just not that exciting =)  ).  If I am going to write something, I want to contribute to triathlon content in a way that is different and offer information that is hard to get other places.  I have decided that using what I know best is the best way to get there. 

This blog will talk a little about my races and experiences as a pro triathlete; but I will primarily discuss topics that utilize my background in biochemistry, medicine and research to take hard scientific questions about performance related topics and translate them into information that can be digested by everyone.  A lot of the topics I have chosen are still question marks in the scientific literature and they require thorough literature reviews to get the most current information.  My job is to do comprehensive research on tough topics and then communicate the most up to date key information to you.  Your job is to enjoy!!

Topics on deck: 

Do altitude tents actually work?

Compression Wear- Commercial Gimmick or Simple Science?

Nutrition: Decoding the relationship between glycogen stores and the right race day nutrition.

Mitochondria: The unsung hero of exercise adaptation