What the Heck is That Hack?

Most people who push hard in a stair race get a nasty cough afterward. Sometimes it lasts for a few minutes and other times it can last for a few days. The common assumption is that the air quality in the stairwell is less than optimal, with dust and/or stale air cited as the likely culprits.

The fact is, it has nothing to do with the air in the stairwell and everything to do with your airway.

“Track Hack” was coined long ago by middle distance runners (i.e. 800 meter to mile runners). Mountain runners get it too. So do aggressive hikers, who call it “Hike Hack.” Even cycle sprint racers get it, although they don’t have a clever name for it that I know of (“bike hack” doesn’t seem to have the same pop to it). These athletes are in their anaerobic zone during most of their event and are breathing as hard as their lungs will let them. They are breathing so hard in fact, their airway gets eroded from the air passing through it. This erosion causes irritation in the airway. This irritation causes a tickle in the throat and this tickle causes the cough.

This irritation can even cause the mucous membranes to produce mucous for protection and lubrication, which can lead to some phlegm in the cough. It can also affect other airways like the nasal passages, which cause sneezing in that case. This erosion can even break little capillaries in the airways causing the taste of blood, or a metallic taste in the mouth.

Sounds bad for you, right? Well, it’s not. It’s just a nuisance.

Vertical training like stair racing tends to produce the hack more often and more severely than other sports. The vertical component of locomotion tends to make us breathe deeper and faster than other sports, mainly because we aren’t adapted to going “up” fast for more than a minute or so. We are more adapted for flatter surfaces because that is what we do most of the time.

The shape of your throat has a lot to do with it too. Some people don’t get the hack no matter what their exertion or fitness level. Others practically get it just thinking about a stair race. I’m one of those lucky few. Even though I train on stairs often and have done over 30 stair races around the US, I still get it when I train hard or when I do a stair race.

What is the solution? Well, there are two as far as I have found. Either slow down so you don’t breath very hard, or wear a mask. My mask (pictured above) causes me to breathe back in my own warm moist air. This warm moist air is easier on my airways so I don’t get the hack or the sneezes. Other people see me in a mask and they assume it’s further confirmation of their suspicion about the dusty stairwell, but that’s not it at all.

Since this is such a common assumption and resulting complaint, many race directors have had the stairwell air tested. In every case, the results have come back showing the air to be just as good as anywhere else in the building and no more dusty – even later in the race after lots of people have gone and the stairwells are crowded. The oxygen levels haven’t changed either, which is another conclusion people jump to.

In fact, because the stairwell is more humid and warmer later in the day from the other racers’ bodies and breathing, you will be LESS likely to get the hack.  Cold dry air is the worst for causing the hack, so doing fast stairs outside on a cold dry day will give it to you worse than any indoor stairwell could. Especially if it is a long stairwell or aggressive hike beyond 10 minutes of sustained high levels of effort (i.e. 80% or more of your max heart rate).

Training does help as your throat will adapt and get tougher, but if you are a “hacker” like me, you probably always will be to some extent. Even as your throat gets tougher with conditioning, so do your legs, heart and lungs, so you are able to put more into it, therefore increasing your ability to erode your airway and continuing to cause the hack.

So is it hopeless for us hackers? Not really. You can learn to live with it or train in a mask like I do. You can also run part of the race in a mask, take it off when you feel too restricted and then whip it back on at the top as you cross the finish line, keeping it on for about 5 minutes until your breathing gets back into the normal range. My climbing buddy Jeff does this and while he still gets the hack, it is greatly reduced.

The mask does slow me down a bit, but not as much as you might think. I estimate it slows me down about 15 seconds  in a race like the 69 floor Columbia Tower in Seattle. That drops my overall place down about 5 spots, but it’s worth it to not have the inconvenience of coughing and sneezing for 4 days. If I feel particularly competitive, I’ll race without it and live with the after effects, but it’s also a nice excuse to pull out of my pocket when one of my stair climbing friends beats me by just a few seconds.  😉



  1. I’ve read about this a few times now – and your article clears it up. It’s traumatic on the lungs to be breathing at such an intense level. Over here in Thailand I’ve not had any hack – no matter how long or far I push myself – whether stair climbing, running, cycling… the air is always nice and humid. Even in the stairwells – the doors are open so the humid air gets in I guess. I do remember running in the frigid, dry air of Pittsburgh for miles and miles and I don’t prefer that air at all. Reading more of your site today – good articles here! Cheers, Vern.

  2. Thanks for this thorough explanation. I’m new to stair climbing, but encountered this big time yesterday in the Oakbrook Terrace climb which was only 31 floors!

  3. Awesome article. Thanks PJ, the outstanding fitness/stair climb expert scientist. And I agree with Vern above. I did my toughest climb- Taipei 101 Run Up in 2011. By floor 33, my perspiration was like water coming out of a faucet. However, I never remember if I even coughed once during or after the race. The temperature was 100 F outside and inside the stairway maybe hotter. But it was in June and very hot and humid. It was so humid that I barely coughed.

  4. Rob Fischer says:

    Great info, I’ve just done a few stair climbs, first time I was coughing up blood, the past 2 were not quite so bad, but still tough. I’m not too bad through the climb, but when I finish it takes a while to settle down and has me almost vomiting. The mask sounds great for during the climb, any tips on how to stop it and get breathing back to normal after the race? I’ve had yoghurt and bananas suggested?

Speak Your Mind