The art of sprinting

If you've been watching the Tour or, especially for readers in the UK, read the sports pages of a newspaper, you will have marvelled at just how good a sprinter Mark Cavendish really is. Four victories in a single Tour are a rarity and, in someone so young (23), truly awesome - he's already proving to have more potential than Mario Cipollini and Alessandro Petacchi. If this, combined with the British cyclists ruling the sport at the moment, don't instigate interest in the media and the population at large, then cycling as a sport is doomed to play second fiddle to other sports at which... well, we suck.

Anyway, back to sprinting. I've been asked a lot lately about it - why I don't do it in my classes, what it really should be like, proper technique and how to improve it. Well, let's start with what sprinting is NOT - it's not about how fast your legs are moving. Many instructors will ask their members to pick up their leg speed to 130+rpm, some even asking them to pedal as quickly as possible, resulting in a flurry of uncontrolled and pointless activity. Many members like these "sprints" as they feel as if they're working really hard. Absolute tosh - they're doing the equivalent of pedalling downhill, as they will have insufficient resistance to apply any power to the pedals. In fact, it's so pointless that the freewheel was invented to allow us to relax while the wheels go ever faster downhill. Work is measured in power output - no resistance, no power... no matter how fast you pedal. Therefore, no resistance, no work. The key elements of a sprint are power, acceleration and a high cadence.

Too many novice riders will put their chain into the highest gear and then try to accelerate - this is a very slow build up, although it'll feel very macho. Instead, they should be using a slightly lower gear to accelerate faster to a high cadence (95-110rpm), then shift to a higher gear and raise the cadence again. With practice comes knowledge of exactly which gear is best suited for a top-level effort - it's not ideal to have to change gears 3-4 times in a sprint! Say you know you can handle 110rpm at a gear that's 9 (out of 10) - your fast pace before your sprint should be in gear 7, shifting to gear 8 once the sprint starts (when you "kick") and then up to 9 once cadence has reached 110rpm. Keeping your feet moving fast is the key to being able to accelerate quickly and the ideal situation is one where you do not reach your maximum cadence until the finish line - gear 9 at 110rpm on the final few seconds. If your legs are moving too quickly or top cadence achieved too soon, you have underestimated your power output and will begin to lose ground (unless you shift up yet again).

As for power output, it's a difficult point to illustrate unless you have power meters on your bike. The maths, however, is rather simple. Imagine what some instructors refer to as "sprints": 130rpm at gear 2. Say this gives 130 watts of power output. To a bystander, looking at the fast cadences, will think it amazing that anyone can work so hard! However, the equivalent in a proper sprint and all-out effort of gear 9 at 110rpm would be around 500 watts. How does that translate? Well, imagine your driving a Fiat Cinquecento at full speed... as you're overtaken by a Ferrari at full speed. Which car will win in a true sprint finish? Which is pushing out more power, more work? Which is using more fuel? Sounds negative for the Ferrari but, in humans, fuel = calories, so wouldn't you rather be using more of that fuel?

In my classes, I've only ever taught surges, accelerations on a hill and short bursts of extra effort - they are sprints of sorts, in that they require the sort of intense effort detailed above. However, the effort required to perform a sprint similar to those of Mark Cavendish, Chris Hoy, Victoria Pendleton, et al, would require a jump from 500W to over 2000W... beyond the realm of indoor bikes, let alone the capabilities of the riders - but that doesn't mean we can't do our best!

PS - if you have Keiser M3 bikes in your gym, fitted with a power meter, and have wondered what it would take to beat Mark Cavendish... imagine a climb at 60rpm at the highest gear (24). Then it's time to begin your sprint: with that same gear you bring your cadence up to 110rpm!

PPS - don't try it at home and certainly not unsupervised. Oh, and don't blame me if you can't walk afterwards....