If you watch pro cycling events like the Tour de France, then you’ll often hear commentators talk about how many watts the top riders are producing, especially on the big mountain climbs. This figure refers to the amount of power their legs are putting through the pedals, and is a key metric in the scientific and data revolution that has transformed the sport in recent years.
But power readings don’t just have to be the preserve of big stars like Tadej Pogacar or Geraint Thomas: they can be just as helpful for amateur racers and club riders wanting to improve their performance, too. In this guide, we’ll take a detailed look at how these power measurements work, especially with regard to the Functional Threshold Power (FTP for short).
What is FTP for cycling?
Your FTP figure is the highest average power level that you can put out over one hour of typical cycling, and is measured in watts. The calculations are traditionally done through a power meter, a piece of hardware that can be attached to a bike and measures output in real-time, as well as calculating averages.
However, as cycling-related technology has improved, there are many more software platforms that are also able to calculate FTP. For example, indoor cycling apps like Zwift and TrainerRoad can work out your FTP, and indeed will use the figure to tailor workouts to your theoretical levels of performance.
Why is FTP so useful for cyclists?
There are several reasons why working out your FTP for cycling can be so beneficial, even if you aren’t a pro racer.
Firstly, it allows you to accurately benchmark and quantify your level of fitness and performance, and gauge it against other riders you know or even your past performance. Indeed, with specific regards to performance improvement over time, it’s possible to calculate your power-to-weight ratio by dividing your FTP figure by your body weight (with the result expressed in watts per kg).
Another key benefit is being able to pace yourself and deliver consistent effort without going too fast too soon and ‘blowing up’. If you know what your FTP is, then you can ride to that figure for a certain amount of time, especially on a big climb or into a strong headwind. This allows you to complete a set distance at the fastest possible speed your body will allow – and it’s the same reason that pro cycling team directors will ask riders to put out specific wattages for certain periods of time.
How can I do an FTP test?
Testing to determine your FTP is much easier now than perhaps it used to be, thanks to advances in technology. Whether using a power meter, or a smart trainer with the right calculation software integrated within it, you can now easily work out what your FTP rate is in as little as 20 minutes.
After two short, hard warm-ups, you should ride as hard as you can for 20 minutes, after which the software will give you a reading of your FTP in watts. Of course, this will be the figure of what you can sustain over 20 minutes, and what you can manage for a longer period will naturally be lower. Many experts therefore recommend using an FTP figure between 90% and 95% of your 20-minute test result as your ‘working’ FTP figure for longer rides and races.
One thing is very important where FTP testing over time is concerned. As any scientist will tell you, consistent and comparable conditions are vital for getting a valid result. Make sure you run the same test in the same way each time, so that you’re comparing like-for-like.
What can I do to improve my FTP?
FTP is one of the few areas of cycling where you can’t just buy an advantage with your wallet through buying better and more expensive kit. If you want to boost your FTP rate, you’ll have to do it the hard way, through training, training and more training.
Having a baseline FTP rate to begin with can actually support a virtuous circle: by knowing what your limit is, you can try and ride slightly above that limit, which improves your fitness even further and improves your FTP, which you can then push on again in the same way. This enables you to formulate a highly specific training plan that’s tailored to your own body and fitness, and has a much better chance of delivering the results that you’re looking for.
Cycling training experts therefore recommend short-burst interval training at levels slightly in excess of your existing FTP level. For example, you may want to ride four eight-minute bursts at around 105% of FTP, with five-minute recovery periods in between each burst. You should expect to make major gains in a short space of time, but combined with a commitment to training and a healthy diet, you should be able to improve incrementally and consistently.
How much should I rely on my FTP figure?
As this guide demonstrates, there’s plenty of value you can derive from knowing what your FTP figure is and working to improve it. However, it should never be considered the be-all and end-all of your performance as a rider: someone who has an FTP of 300 watts isn’t automatically better than someone at 280.
There are several reasons why this is the case. Firstly, unless you’re going to be competing in a time trial that takes exactly 20 minutes, your FTP figure on its own isn’t going to be of much use to you in competition. It’s also worth remembering that human beings are in better condition on some days than on others, whether that be physical condition, mental motivation, any lingering fatigue, and how much energy you’ve taken on board when you’ve been FTP tested.
FTP levels can therefore change from day to day, and even over the course of a ride: after all, it’s much easier to go flat-out when you’ve only got five miles in your legs rather than 50. As a result, taking an average of many tests over a long period of time is therefore essential for getting the best results.
Additionally, the longer the ride or event, the less relevant FTP becomes. If you’re going to be riding all day in a sportive, or competing in a stage race over several days, endurance becomes more important than all-out power. In this kind of riding, it’s metrics like your exercise economy and your ability to oxidise fat that become much bigger differentiators.
Is it possible to measure FTP without a power meter?
In terms of getting an exact figure, the short answer is no. However, some riders have advocated a complex mathematical formula that allows a rough estimate of FTP to be generated.
The formula was devised by Dr. Allen Lim and works as follows:
Add together the weight of rider and bike in kilograms
Multiply by 9.8
Multiply by elevation gain in metres for the chosen route
Divide by the amount of time in seconds taken to complete the route
Multiply by 1.1 (this adds 10% to factor in rolling resistance and wind resistance
Riding the same route as quickly as possible a number of times and then taking an average of the results should therefore give you an estimated FTP reading. However, it should be emphasised that this is by no means an exact science, and the only way to get a fully accurate reading is to use a power meter. And in any case, if you’re taking your cycling seriously enough to want to know your FTP, then you’ll want to have the most accurate figure to hand anyway.
Get cycling insurance with SportsCover Direct
If you’ve invested in a power meter, you’ll know that they can be expensive bits of kit. That makes it all the more important to get them covered by insurance, in case they get lost, suffer damage that prevents them from working, or are stolen.
At SportsCover Direct, our comprehensive cycling insurance policies can be tailored to incorporate all your valuable accessories, including power meters. That way, you won’t end up out of pocket if you suffer unforeseen circumstances that aren’t your fault, and you can train hard and push up your FTP with confidence and peace of mind.
To find out more and explore our flexible monthly payment plans, take a closer look at our cycling insurance