One critical mistake runners make when flying to a race - DOC

One critical mistake runners make when flying to a race

Today on the Doc On the Run Podcast, we’re talking about the one critical mistake runners make when flying to a race.

Destination races hold a lot of appeal. Awe inspiring scenery. Amazing cultural experiences. Fast, flat courses. We spend countless hours and significant sums of money just getting to some of these destination marathons and triathlons. 

Obviously, if you are heading to a key race in a far-away place, you want to have the best race possible. Incredibly, many runners make one simple but crucial mistake that can truly hamper the chances of success in finishing under your goal time.

A few years ago I was racing Ironman France. At the beginning of that year at our annual kickoff meeting, a  large group of us in the SF Tri Club decided to all do Ironman France. 

Ironman France is not an easy course and we all wanted to do well. For months and months, we trained. Cold group bike rides starting in the early mornings. Long runs in the mist and rain. Track sessions in the dark. 

We all put in a huge amount of training to be at our best when we it was finally time to dive into the Mediterranean and begin our 140.6 mile day. 

Nice, France is a long way from San Francisco.  If I remember correctly, it took about 17 hours to get there. 

Nathan, a member of our group and qualified ring-leader had arranged a large apartment close to the beach, where several of us would stay. As soon as I got to the apartment, I found David who has arrived just a little earlier. We decided to head out to the grocery store to stock up on supplies for our stay.  

David is an interesting guy. He is a strong athlete, and a professional pilot. He had flown in the military. He is also a little taller than me, at about 6’ 3”.

While we were walking down the sidewalk, we were talking about how stiff and uncomfortable we both were from the long flight. Then he said, “Man, my legs feel all ‘jiggally’ every time I take a step.”

At the time, we were both Ironman race-ready and seriously fit. I was at an unhealthy but typically race-fit low body fat level. Because of that, my legs were simply covered in veins. 

When David commented that his legs were ‘jiggally,’ I looked at David’s legs. No veins visible anywhere. 

There are basically only 2 reasons you can’t see the veins in your legs.

1.You have a lot of subcutaneous body fat hiding the veins in the skin.

2. You have fluid in the legs making the veins less visible. 

David was a super-trained Ironman triathlete. He was anything but fat. We had trained together for months and our fitness was pretty much the same. Our build and body composition was also about the same. But our legs looked completely different as walked down the sidewalk to the grocery store in Nice. 

“Dude, tell me you didn’t fly all the way from San Francisco to France without wearing compression socks!” I asked.

“What are you talking about? I thought compression socks were for old people.” he answered.

“Okay, David. Seriously. I know you’re not a foot doctor, but isn’t it kind of common knowledge among pilots that your legs can swell when you fly? What exactly do they teach pilots in the military? Don’t you have to take some kind of classes on flight physiology or something?” I asked.

After we go back from the grocery store, we assembled our bikes and went out for a ride to spin some of the fluid out of our legs. 

Knowing he was going to have a rough time running on swollen legs, I offered a pair of my compression socks to David. I told hime to put them on, and keep them on for the next 24 hours.”

The next morning I was in the kitchen making coffee when David got up. 

“Hey, man…look. My Ironman veins are back!  Those socks are magic. They made me look fit overnight.” David beamed. 

 If you really think about it, it is just amazing that runners will thinks about the weight of their running shoes, and refuse to add any additional shoe insert weight, yet they will allow dead weight, in the form of fluid retention to pool in the legs the way to run a marathon. 

Every sing step of the way, you have to pick that extra fluid up, swing those swollen legs through the air and repeat, for the entire 26.2 miles. 

Skinny legs are lighter legs. Swollen legs are heavy legs. Which do you want to want have to move.

When you sit in a cramped seat for long periods of time, like when you are traveling on an intercontinental flight, you cannot move much. Movement is the vehicle that mobilized the fluids in your legs. 

When the muscles in your legs fire, and tense up, they squeeze and squish the veins sandwiched in between the muscles. The compression of the vessels, pushes the fluid up out of the legs. 

To make matters worse, the large veins in the back of your thighs are both bent and forcible compressed while you sit. Your weight sitting on those veins, couple with the minimal movement combine to increase the odds of fluid pooling in the legs. 

In addition, the decrease pressure in an airplane cabin at altitude and can also contribute to swelling in the legs. You have to take action to make sure you land with legs that are light and 100% race ready.  

Compression socks are the simplest and most effective tool every runner should use on any flight to a marathon, triathlon, ultra-marathon or any other destination race. 

I fly to a lot of medical conferences. Several times a year I am invited to teach doctors about running injury treatments. I never, ever fly without compression socks. 

Even when I wear shorts on a flight to Hawaii, I wear compression socks. And yes, it does look silly wearing knee-high compression socks with shorts. In an effort to minimize appearance of ridiculousness, I carry compression socks in my backpack. I get through security, walk thorough the airport, an then, after I sit down in my seat on the plane, I pull out my compression socks and put them on for the flight. When the plane lands, I take them off again.  

If you don’t believe me and you really don’t think compression will make a difference, try flying with only one compression sock. I am betting you will notice a difference in the visibility of the veins in your legs between the compression sock leg and regular sock legs.

When you buy compression socks you will almost certainly find the range of choices overwhelming. But here are a couple of simple tips to make your sock shopping simpler. 

Get full-length knee-high socks. Don’t use calf sleeves. Get full socks. Do not get open-toe compression socks. The socks should cover everything form your toes all the way up to just below the knees. 

Compression is measured in ratings expressed in mm/Hg. You want to find something in the 20mm/Hg range. To further confuse you, medical grade graduated compression socks also have two numbers. 

For example, compression socks rated at 18-23mm/Hg means that the socks apply 23mmHg of compression at the toes and gradually decrease in compression to a level of 18mmHg of compression at the knee. 

Basically there is more elastic material (and hence more compression force) sewn through the toes and less at the knee. The reason for that is you want to squeeze the fluid up from the foot and out of the leg toward the big veins in your torso. If the compression was higher at the knee, the sock would actually act like a tourniquet and increase fluid retention by holding fluid captive in the legs. 

The exact brand of socks doesn’t really matter that much. I have my favorites, but none of them sponsor the podcast nor give me socks, so I’m not going to play favorites. There aye many high quality brands. 

In general my opinion is compression socks made of nylon material generally have the most even compression and highest level of durability. They last longer. Cotton and wool compression are more comfortable.

The cotton and wool compression socks I have tried really do feel better, but they seem to stretch out and lose some of their compression faster than the nylon variety. Regardless of the material, all compression socks will last longer if you air dry them and refrain from baking them in a hot dryer. 

Be forewarned of impending sticker shock. High quality medical grade compression socks are expensive. Most of the compression socks I have cost $35 to $45 per pair. But they are worth it. 

If you don’t believe me, just ask David. One day in Nice, in one pair of compression socks his legs went from fat to fit, overnight. 

One last tip, that I almost forgot. There is a right way and a wrong way to put on compression socks. So I made a quick video for you to show you exactly how to put on the socks without as much stress and strain, and to help ensure you get steady even compression. Check it out. It’s free. Just go to the show notes for this episode under the podcast tab at .


If you have a question that you would like answered as a future addition of the Doc On The Run Podcast, send it to me And then make sure you join me for the next edition of the Doc On The Run Podcast!