What is Negative Splitting?
Monday, August 17, 2009 at 1:00AM A coaching client recently asked me "What is negative splitting?" Here was my response.
A negative split is where you do the second half of a workout or race faster than the first. Essentially, what it forces you to do is restrain yourself a little bit on the first half, giving yourself the energy to actually finish strong. Finishing weak makes you go really slow at the end, which is far slower overall than if you simply escalated your speed gradually.
You mentioned how there's no structure to your workouts. Negative splits are not only essential for longer workouts, but they are the ultimate expression of control of a workout. Anything that's an hour or longer, you should go for negative splits. Sometimes you'll accomplish it, sometimes you won't, but the goal is to try. Again, this is because people have the tendency to start off too fast and then crater towards the end. Science and timing proves again and again that you will go faster overall if you go faster the second half than you did the first.
Your workouts will give you better results if you use it. Believe me, your competition is.
On something longer, like a 40k bike race, you'll have even better results if you break it up into smaller portions. Work backwards from what you want to do at the end. 24 mph the last quarter, 23, mph the third quarter, 22 mph the second quarter, 21 mph the first quarter. Mph is hard to use as a gauge of effort on the bike, so you're actually better off using wattage or heart rate instead. Mph can be affected by hills and wind far more than your effort level. To do splits properly, you'll need to have a watch that does pacing and laps. I have a Suunto T6c that tells me my pace and I can pre-set laps based on time or distance. Your Garmin does the same, I'm sure. You should have your watch avg your HR per 10k in the race. The 1st 10k could be 155 bpm, the next 165 bpm, the next 175 bpm, and the final whatever bpm you can max out at. Again, you should engineer your target bpms backwards from what your max can be.