What's the weather doing this week? Chances are you'll know, because you're a bike rider. There are few more diligent weather geeks than we who enjoy riding bikes outside – because it can have such a dramatic effect on the enjoyment of it.
But what, really, is the bike rider's nemesis? Ice, surely, is right up there, but many of us would also single out rain. And wind. The invisible and capricious foe that might offer a helping hand – or conspire to ruin our progress and enjoyment, often both within the same ride.
Which leaves us in a quandary.
When you look out of the window on the morning of a ride and see the trees bending in a stiff breeze, do you celebrate because you know you're going to enjoy a tailwind? Or do you feel instantly demoralised at the thought of an inevitable headwind.
Assuming you don't decide to sack it off altogether, which way do you head out the door? Because unless you're riding from A to B, you're going to experience both head and tailwind on the same ride.
"Unfortunately, we're all at the mercy of more headwinds than tailwinds," says Dr B. Xavier Disley of aero experts Aerocoach. "You're going to be going slower and spending more time into the headwind than you will do coming back with the tailwind."
This is because you'll almost inevitably be going slower for any given distance into a headwind than in a tailwind, and therefore taking more time over it. Take a hill with an ascent and descent of the same length and gradient – you'll take longer over the ascent than the descent because of your speed. Head and tailwinds work in the same way.
Just for fun?
Disley points out that your riding goals can dictate how you approach the wind. The big question is whether you want the headwind first, or the tailwind.
"Is it a training ride, or is it just a fun ride?" says Disley. "If it's a training ride and you want to get the most benefit from it, then you want to make it as hard as you can when you can. So you'd want your headwinds up the climbs.
"Whereas if you wanted to even out your speed, you'd probably want to have your tailwinds up the climbs, and then your headwind on the descent part. And then that keeps everything a lot more even."
Like a lot of people, Disley says he prefers to head out straight into the wind while he's still fresh, rather than saving it for the second half "so when you're knackered you're not struggling into a headwind and killing yourself".
There is more besides. Because of the exponentially growing nature of drag, you might consider attempting to engineer your ride so that the headwind falls at the part where you would naturally be riding slowest. This is because it would have less effect on your speed – or at least, the power required to maintain that speed – than it would if you were riding faster.
But the mental and emotional equations need balancing against the scientific ones. If you had the choice would you really want to save the headwind and hills for the second half of your ride? While the science insists the headwind would affect you less, knowing you had by far the hardest part of the ride to come could damage morale and spoil your ride.
Doing it this way would also mean you would be more tired when you hit the headwind, meaning it would be liable to slow you down more.
The other side to this coin is that your freshness in the first half of the ride means you can more readily adopt an aero position to combat the wind. Sixty miles into the ride, your arms and shoulders and back might put up a good deal more fuss when you try to hunker down low.
Friend and foe
Throughout this piece we've examined headwinds, essentially, as the enemy. But it can be worth reframing that. Headwinds might rarely (never) be enjoyable, but they can make for a useful training aid.
A little like a hill, riding into a headwind requires more power for a given speed. No hills? No problem. This can be particularly effective on a flat road if you want to carry out an interval session. (It goes without saying that this is a quiet road and you're being careful, right?).
Doing the efforts into the wind means you'll go slower and not as far for each effort, making it more practical.
It also offers a handy push back to the start.
Headwinds on the average cycling loop are very difficult to quantify, because the shape of the route is almost never uniform, and even the wind itself can change direction.
A perfectly straight out and back, for example, or a perfectly circular loop, might result in equal parts head and tail, but this is rarely the case.
As Disley says: "It's a tricky one to determine, because winds are so changeable and weird. You could have a bit of a crosswind for most of your ride, which can actually give you a bit of a boost at certain points when you turn direction.
"I think the thing to understand is that you'll spend more time in the headwind than you will in a tailwind, all things considered," he concludes.
So, there are various ways you can approach a headwind, but one thing you can't do is make it go away. Tackling it head-on (quite literally) in the early part of the loop is going to make for the most pleasant ride. But if suffering is your goal (or at the very least raising your VO2 max) then you can use it as a tool for efforts, or even save it to the end if you're feeling particularly masochistic.
Either way, you'll appreciate those perfect windless days that come along every now and then even more.
