Negative Splits

I’ve found that one of the hardest things for me to do is to negative split a course, whether it be running or riding.

This basically means the second half should be slightly faster than the first half. There shouldn’t be a huge difference, and as a general rule, the 51-49 principle is usually recommended. So the first half of a 10-minute or longer event (race, training run, etc.), should be completed in 51% of the total finish time. In road running, nearly all world records have been set with the first half run slightly slower than the second half.

Case in point was the Boston Marathon on Monday. Robert Kiprono Cheruiyot set a new course record with a time of 2:05:52. He ran the first half of the race in 1:03:27 (50.4% of finish time) and the second half in 1:02:25 (49.6%).

The main thoughts behind the 51-49 principle are the following: If you go out too slow, you will never be able to catch up. If you go out too fast (like I did in the Papa John’s 10 miler), acidosis increases rapidly and your body will never recover. It’s easier to tolerate high acidosis for short periods (like at the end of the race) than long (like the whole race). Your joints become more lubricated and muscles warm up when you start out slower. Best of all…you get to pass all those people that passed you early on in the race!

So why don’t people (including myself) follow this principle? First off, it’s tough to hold back at the start of a race. Adrenaline is pumping and you can be running faster than you think. Then there’s the confidence issue. If you come out “slower”, will you have enough left to pick up the pace during the last half? Some people even have the misguided belief that time “gained” early in a race by going out fast is greater than that gained late in a race.

The best way to learn/teach yourself to do negative splits is to practice them in your workouts (you race the way you train). I’ve attempted to do this several times, but with my RunKeeper App acting up lately, it’s been impossible to tell what pace I am actually running until I’m done.

I’m going to attempt to pull off a negative split during the mini-marathon on Saturday…more on that later this week.



Warm-up (1.2miles): 9:46 (8:08 min/mile pace), Avg HR = 143
1/2 mile intervals
1) 3:10 – Avg HR = 158
2) 3:14 – 161
3) 3:15 – 161
4) 3:17 – 165
Total workout – 3.20 miles in 27:48
The plan was to do a total of 8 intervals, but due to the lack of sleep the night before, I wasn’t feeling it, so I stopped after just 4. If there’s anything that I’ve learned, it’s that if your body doesn’t feel right…don’t force it!
After the running, I did an hour of weights (legs, chest, shoulders, abs).



I did a Fartlek run this morning. Which means that once every 10 minutes, I picked up the pace for 1 minute.
I ended up covering 7.16 miles in 54:06 (7:33 min/mile pace). This was a pretty good run and I feel good heading into Saturday’s race.


Warm-up (6:22 of drills)
Swam 0.6 miles in 20:47 (34:38 min/mile pace)
4 x 48yd (1 lap) intervals
1) 40.92
2) 40.90
3) 40.38
4) 39.94
Cool down (4 minutes of easy swimming)
Total Workout: 1776 yards in 37:24

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