Do You Run Faster with Shaved Legs?
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When you’re working towards a running goal, there are times when you would consider almost any possibility in an effort to achieve it, even possibilities that seem a bit crazy. One of the crazy ones is shaving your legs to help you run faster. While crazy, it’s actually pretty popular. Does it actually work?
No, shaving your legs will not make you a faster runner. Not in any noticeable way, that is. You’ll see much greater speed gains from overall body position and posture than leg or arm hair.
Trying to get any advantage you can, you may still be poised with your razor, ready to test the theory of whether your leg hair is actually the culprate holding you back from faster speeds. Let’s dive into the popularity of shaving in sports and why it won’t make you a speed demon.
What’s the Theory Behind Shaving and Speed
The obsession with leg hair and speed has to do with “aerodynamic drag” or “air resistance.” This basically refers to the resistance of an object as it moves through space because of air hitting it and pushing against it. The bigger an object is, or area it has, the more drag it will have. There’s just more space for the air to push against (source).
The theory is that leg hair contributes to drag. The more hair you have on your legs, the more area you have, which increases your drag. Basically, leg hair makes you slower.
But, is this really true? And, if so, how much slower does it make you? To understand shaving and running speed, we first need to understand shaving and cycling speed.
Shaving DOES Make Cyclists Faster
Cycling is one of the sports where shaving originally became popular. Triathletes, professional cyclists, and even hobby bikers started shaving their furry limbs. It seemed like a good idea, but it’s hard to isolate variables and actually know what’s contributing to speed gains without running an official experiment.
So, that’s just what Jesse Thomas did. As a pro triathlete, Thomas wanted to put some speed theories to the test. How would outfits, helmets, wheels, positioning, and yes, leg hair contribute to his speed? Jesse spent some time in a wind tunnel to find out.
The results are not what you would expect. Here are Thomas’ speed savings with each component (source):
Yeah, that’s right. Shaving his legs saved Thomas a whooping 15 watts. Special equipment that bikers would pay thousands for couldn’t even match those speed games. Granted, Thomas had fairly thick leg hair. Not crazy, but pretty hairy. To give you some perspective, researchers created a Chewbacca scale from 1 to 10, with 1 being silky smooth and 10 being Chewbacca status hair. Thomas came in at a 9 on the scale. That’s only 1 point away from the hairy Chewbacca we know and love (source).
Researchers used this Chewbacca scale to measure the hair growth of 6 pro cyclists. Then they had them shave and put them to the test. On average, riders saved 70 seconds per 40 km when they shaved their legs (source). That’s not bad!
So, it does seem like shaving has a positive speed impact for cyclists. Shaving is only one component of the speed puzzle though. As we saw from Thomas’ results, there are numerous factors that can increase speed. 15 watts of speed is great just from shaving legs, but 15+8+5+3 is even better. It’s important to look at the whole picture and not just assume that shaving alone will be the magic factor. It does help though!
Does Shaving Improve Running Speed?
Alright, so if bikers can see such great speed gains from shaving their legs, runners must find the same benefits, right? Well, no, not exactly.
Remember that cyclists are moving really really fast in comparison to runners. A Tour de France rider can hit speeds of 28 mph. These cyclists might as well be super heroes though. Let’s look at average riders who normally top out around 18 mph (source). Now, let’s look at runners. If you’re running at about an 8 minute mile pace, you’re running at 7.5 mph. The speed differences between 18 mph and 7.5 mph are pretty different to say the least.
When you’re running, you’re just not moving fast enough to make your leg hair a big factor. In fact, being aerodynamic in general isn’t a big factor in running. Yes, professional runners wear form fitting suits and sleek gear, but the focus isn’t on aerodynamics in the same way it is with cycling. Things concerning aerodynamics like building momentum, coasting down hills, and reaching maximum speeds just aren’t as important with running.
Also think about how much time cyclists spend thinking about finding aerodynamic bikes, clothes and helmets. As runners, we spend very little time thinking about these things in comparison. If we aren’t even worried about the drag of our shirts or pants, why would we be worried about the drag on our leg hair? Heck, some of the people that are worried about their leg hair have 10x more hair on their heads!
I haven’t found any running-specific scientific studies that address leg hair, but that might be because it’s a non-factor. No one is going to invest the time and money required for a legitimate scientific experiment if there isn’t a worthy hypothesis behind it. Leg hair and running just doesn’t deliver.
Is There Any Value to Shaving My Legs as a Runner?
If we forget speed, there are actually some good reasons to shave your legs as a runner. Some are obvious, but others might have you nodding your head with a new sense of appreciation for shaving.
1) It makes you feel good
This is one of the obvious reasons. If you like the feel of smooth legs, you don’t need any other excuse to shave them. Just say that you like smooth legs and move on! There doesn’t need to be some greater purpose like improving your aerodynamics and speed. Embrace that it makes you feel good and embrace it. On the other end, if you enjoy NOT shaving your legs, you don’t have to feel like you’re sacrificing your running speed by keeping your leg hair. When it comes to leg hair, you do you!
2) It makes KT tape and bandages easier to take off
I’m no cry baby, but I will admit that it hurts to take off KT tape and bandages off of unshaved limbs. If you use these tools often, you may want to consider shaving your ges. If you don’t, you may end up with bare legs anyway given how much hair that gets pulled out every time you pull off a bandage.
3) It’s easier to manage injuries if you fall
It’s rare for me to write a post for BTA that doesn’t talk about falling. I fall a lot. It’s quite a specialty of mine. This has allowed me to run my own, unscientific experiments. I’m a runner who shaves my legs, but not my arms. On those fun falls where I manage to bang up both my arms and my legs, the wounds on my legs are much easier to manage. On my arms, cleaning and bandaging just takes longer. It also hurts given what we talked about in #2. While I wish you a fall-free running life, a shaven surface is easier to deal with if you do.
So, what’s the moral of the story with shaving and running? Go with whatever floats your boat and don’t worry how it impacts your running. It’s unlikely that shaving will influence your running speed in any way. If it does, it will be minimal. You would get much more bang for your buck focusing on your form, stamina, and overall endurance. As far as running is concerned, shaving is not a big factor.
Hey, I’m Diana! I’m an occupational therapist and a long distance runner. I’ve run more races than I can count from 5ks through full marathons, including the Boston Marathon. Right now, my PR for the marathon is 3:09 and 1:26 for the half. I’m a bit obsessed with running and sharing what I’ve learned along the way. Let’s crush some running goals together!