Found on Competitor.com and written by Roy Stevenson
Using some basic strategies, you may find yourself finishing faster and feeling more confident each time you toe the line.
First we can look at the three standard racing tactics and strategies used by semi-serious runners and middle of packers:

Spectators applauding for marathon runners
Positive Splits
Race out as fast as you can and hang on as long as you can. This tactic is definitely not recommended. Read on to find out why this should be avoided.
Negative Splits
Start slowly, gradually speed up then come through with a roar in the last mile or two.
Even-Paced Racing
Run at a steady, even pace the entire distance, so your two halves of the race are nearly identical. This has some great advantages and is how most runners get their best times, and world records are set. Perhaps a better way to explain it is “even effort,” meaning that your effort is distributed evenly along the course. So when you come to hills, you will still slow down, but your effort is maintained.
Benefits Of Steady Pace Or Negative Split Races
A slow early pace conserves greater stores of glycogen, whereas fast early pace depletes glycogen supplies at a horrendous rate — a critical concern in any race over 5K. The rapid glycogen burn results in a large increase in lactic acid — translating into a much slower pace.
A moderate early (even) pace or negative split race minimizes the threat of glycogen depletion and reduces your chances of premature exhaustion — your energy is economically burnt during the entire race. Laminate a pacing chart and hang it under your race numbers where you can refer to it easily.
Base Your Race Plan On Your Desired Race Pace
Numerous factors come into play when planning your race strategy. It’s all about setting the right pace to get you to the finish in your fastest time with little energy left. Your pace must be set according to your fitness, the topography of the course, and ambient weather conditions.
An example or two best illustrates the interplay between these factors. If it’s a hilly 10K course, 80 degrees, 80 percent humidity, with a 5 mph headwind and you are not particularly well conditioned, clearly you would need to set a conservative pace only a notch above your standard training pace for this distance.
“Hills can figure considerably into tactics,” says marathoner Cliff Richard. If there’s a big uphill late in the race, I know I need to save energy for that.”
On the other hand, if you’ve just finished a three-month conditioning phase, the course is flat, with a near perfect temperature of 50 degrees and low humidity, your pace should be near maximal. Regardless of the weather conditions, your early pace must be slower than your desired race pace, at least for the first mile.
German marathoner Uli Steidl plans every race beforehand, and generally, “I try to run at even pace. But race tactics for any particular depends on many factors, including but not limited to my current shape, other runners present, weather, race goal, course profile, etc.”
Heat And Humidity
According to research, runners start to slow down past 55 degrees, and start suffering at 65 degrees. When humidity is thrown into this mix, the slow down is even more dramatic. Going out too fast in extreme heat and/or humidity can even cause heat injury.
Therefore in high heat and humidity, the prudent runner starts off at a pace he can maintain, perhaps as much as 30 seconds per mile slower than normal. Galloway recommends slowing your goal pace by 3-5 percent in 60 to 70 degree temperatures; 7-12 percent in 70 to 80 degree temperatures; and by 20 percent above 80 degrees.
The Start
How many of us are guilty of flying off at a suicidal pace in the first mile or two of a 10K because we were so excited?
“The longer the distance, the more energy conservation and muscle recovery come in to play,” says marathoner Ann Armstrong. “Spend it early and you will be miserable in the end.”
With competition, our adrenal glands dump large amounts of stress hormones like adrenalin into our bloodstream, causing us to start far too quickly. So hold yourself back and start very slowly — up to 30 seconds slower than your desired race pace. Don’t worry about losing time this way — you’ll make it up when it counts later in the race.
While Armstrong doesn’t intentionally go out fast, it often happens.