Your pacing strategy
What’s the best way to hit your time goal? Some marathoners go out hard and try to hang on. Others aim for an even pace. A few go easy early on, then run the second half faster (known as a negative split). You need to understand the physiology involved with running the marathon, and its implications for your optimal pacing strategy. Your ideal marathon pace is close to your lactate threshold pace. Run faster, and lactate accumulates in your muscles and blood. Hydrogen ions associated with lactate deactivate enzymes needed for energy production, slowing you down. Plus, exceeding lactate threshold pace also means you use more glycogen, depleting your stores faster. This means your best strategy is even pacing. If you run much faster than your overall race pace for part of it, you’ll use more glycogen and accumulate lactate.
Most runners shouldn’t try to run dead-even splits, however, because during the marathon you’ll gradually fatigue your slow-twitch muscle fibres and recruit more of your fast-twitch fibres. Unfortunately, these fast-twitch fibres use oxygen less efficiently, so your running economy will decrease slightly during the race, along with your lactate threshold pace. The result is that your optimal pace will be slightly slower during the latter stages of the race. The most efficient pacing strategy is to run the second half two to three per cent slower than the first. If you run negative splits, the chances are you ran below optimal pace in the first half and therefore could have clocked a faster finish.
For world-class marathoners, optimal pacing is different. They’re so highly trained they have a lower tendency to recruit fewer economical muscle fibres so, for them, the most effective strategy is running the second half at the same pace as, or even slightly faster than, the first. Most recent world records have followed this: Paula Radcliffe’s 2:15:25 at the 2003 London Marathon split into 68:02 and 67:23; Patrick Makau’s current WR 2:03:38, set in 2011 at Berlin, saw him hit halfway in 61:44 and run the second half just 10 seconds slower – almost perfectly even.
Even world-class marathoners often run the second half 30-90 seconds slower than the first, though. And most marathoners will run optimally by gradually increasing their effort over the second half in an attempt to run close to even splits, which often results in a second half a few minutes slower than the first 13 miles.
The first half
It’s easy to get carried away with a fast first mile, but control yourself and run at, or even a bit slower than, your goal pace. You won’t have done much of a warm-up, so your body won’t be prepared to go faster than race pace. Also, as mentioned earlier, going out too fast will burn extra glycogen and produce lactate. After the first mile, relax and try to settle into a rhythm. Establishing a comfortable style early on helps you avoid tightening up later. Go through a mental checklist: shoulders relaxed; body upright; breathing steady; stride rate even; and any other cues you use to maintain your form.
Have a sports drink at the first station. It’s good to take in carbs from the start rather than waiting until you feel tired and light-headed, when it’ll be a case of too little too late. The longer you can postpone glycogen depletion, the longer you’ll be able to hold your pace. Drink fluid at every station, guided by thirst – for more detailed info, see Filling your tank, page 52. Mentally, the first half is the time to cruise. Save your mental and emotional energy for the much tougher second half; try to get the first half out of the way at the correct pace using the minimum mental energy.
To group or not to group?
If you’re running into a headwind, there’s a substantial advantage to running in a group and letting others block the wind. You may need to do your share at the front, but you’ll still save considerable energy compared with running on your own. Even on a calm day, it’s better to deviate slightly from goal pace rather than run long stretches by yourself. In big city marathons, you’ll be among runners at any pace, but in smaller races, you have a reasonably high chance of running miles alone. In that situation, it may be worth running a few seconds per mile faster or slower than planned to stay with a group. Drafting behind other runners gives you a small energy advantage, but the key benefit of staying with a group is psychological. It means you don’t have to worry about setting the pace; you can simply relax and go along with the group.
As a rule of thumb, don’t deviate from your goal pace by more than eight to 10 seconds per mile during the first 20 miles. The best way to judge whether to speed up in order to latch on to a group or not is by how you feel. If your breathing is uncomfortable and you sense you can’t maintain that intensity to the finish, relax and let them go. The group won’t carry you the whole way beyond your level of conditioning. During the final six miles and 385 yards, be more independent. If no one else is running at your pace, go it alone. The chances are this will work well for you psychologically, because if you’ve prepared well and run a fairly even pace, you’ll be passing other runners throughout the final miles. And nothing lifts the spirits quite like overtaking late in the marathon.