Riding down hills is hard.
Not only is mountain biking down hills really physical, but you need to brake at the right places, handle some gnarly terrain, pick the best lines, and pump and flow if you want to go fast.
There’s a lot to think about and there’s a lot for your body to do. Add in pedaling and it’s even harder.
But do we really need to be doing all that pedaling?
I wrote before about pacing, but this one is all about coasting– and getting confident in being able to do it!
It’s true that we can’t all coast our way to World Cup DH victories like Aaron Gwin, but why are we not practicing coasting all the time?
One of my original research studies looked at coasting.
And specifically, how much energy it took to coast versus how much energy it took to pedal on a 1km MTB descent.
We had riders ride up a hill at their threshold, and then blast down the hill at race pace. The first run was practice, and the second and third were either coasting all the time or pedaling whenever they wanted (in a random order). We also measured vibrations and added a road descent of the same length at the same speed.
We measured their VO2, heart rate, time and power output the whole time.
Their average VO2 (that’s representative of the energy their bodies are using) was lower in the coasting and road trials than when pedaling.
And there was no difference in the time it took to get down the track when coasting or pedaling.
Everyone was really surprised by these results–even the riders who were testing! Each rider felt much slower when coasting, but the stopwatch did not lie.
But how is it possible to go fast without pedaling?
Hills are free energy (aka FREE SPEED)
When you get to the top of a hill on your mountain bike, the mountain is your oyster.
You can do with it what you please.
And if you let it, it will let you go really, really fast!
This is thanks to the POTENTIAL ENERGY we have as we look down the trail.
[Skip this part if you hate maths]
Potential energy = mass x gravity x the height of the hill
And we can convert this to kinetic energy as we let gravity do its thing. This is the energy of us while we are moving and actually riding down the trail.
For simplicity, let’s say you weigh 100 kg and you are staring down a hill that loses 10 meters in elevation.
If we round up gravity, your potential energy is 10,000 joules. That’s actually quite a lot of free energy!
This is equal to the energy of you sprinting at 1,000 watts for 10 seconds. Or 5,000 watts for 2 seconds. That is a really good sprint!
Thanks, hill 🙂
We are our own worst enemy
As we start riding down the trail, we start do do a few things–some good, some bad.
We might hit a corner perfectly, pump a roller or float over a pile of rocks and roots.
Or we might sprint hard into a corner and slap on the brakes at the apex and through the turn.
These are not that good.
If we can pump and flow and brake perfectly every time, we will have fun and ride safe and fast. But if we sprint all the time, we will eventually get tired.
When we get tired, we start making mistakes. We stop being able to pump and flow when we get tired. We smash into holes. We brake at the worst times. We ride sloppy and slow overall.
Considering the simple equation up above, it is possible that by adding in a lot of pedaling energy, we are forcing ourselves in to the position of taking away all the free energy through poor braking and bad lines.
But the hill is basically gifting us a few hundred sprints! Why not let the hill “sprint” for us?
Or at least: what if we let the hill do its own work at least some of the time?
Why do we fight against ourselves?
Let’s face it: there are times when we absolutely need to pedal or brake. If there is a 30 second climb in the middle of the track we will absolutely need to dig deep to get up it.
But, there are also times when pedaling is not making us go any faster– it is only making us more tired and forcing us to brake more!
In our test, we hypothesized that riders were able to focus better the entire descent – and make smarter, smoother choices – because they did not overexert themselves by sprinting!
We need confidence in the coast!
Every rider looking to get faster needs to practice coasting down hills more.
While it is definitely true that you can’t always coast your way to a win like Aaron Gwin, you can learn how to execute a good coasting strategy for yourself and for each kind of track or terrain.
I recommend for every athlete to regularly do timed practice races and compare their speed in coasting versus pedaling runs.
Time and time again, riders say they feel much faster during their pedaling runs and much slower on their coasting runs.
And no matter what the stopwatch says, they always finish the coasting run feeling fresh.
Being fresh is good!
Just like the riders in my study, we all know we ride well when we are fresh! This is why we get fit, even if we race downhill and enduro!
When we talked about riding singlespeed enduro, we talked about forcing ourselves to focus on MAINTAINING SPEED rather than on SPRINTING TO ADD SPEED.
In the end we can make better decisions and continue to ride smooth and maintain our speed when we are fresh.
It is all about that balance of going fast and making sure we continue to go fast.
How you can try
Set up your own pseudo race with one or two separate mountain bike descents on terrain similar to your next race. Follow your normal warmup routine, and complete a series of race-runs, alternating between coasting and pedaling each time.
Record your time, your power output, your heart rate and how you felt on each run.
Head home and analyse your data.
Did the pedaling make you much faster? Is it possible to remove some of the pedaling for your next run and only pedal in key sections? Will this help you ride smoother in other sections?
When you know, you know
If you don’t try this you will never know what you will be able to get away with or understand how smooth you can ride stage after stage and day after day.
It may be you can simply start with a reasonable off-the-line sprint and pump and flow to the finish. Or that you need to sprint in the middle on the small rise. Or that you need a strong sprint at the start and again at the finish.
It’s worth finding out–it could make the difference for your race 🙂