Taking the second half of your run at a faster pace is great prep for the negative split racing strategy; where you start out slowly, then push your pace at or just before the middle mark. Aside from being a racing strategy, saving your speed for the second half of the run means your body will be completely warmed up and ready to be pushed. Just because the weather is cooling doesn't mean you should leave your speed work out in the cold. Try a negative split run the next time you head out the door.
- Find an "out and back" run. I use Map My Run for this.
- Warm up by either mileage or time but pick some kind of physical marker, which will be your starting and stopping point for the main part of your run. I always use a specific intersection for starting the main part of my run after warming up for a half mile into my run for a short run, or a mile into a longer run. Once you start your main run, set your stopwatch.
- Run at your predetermined pace and when you reach your turn around point, check how long it took you to reach the midway point. If your watch has a lap/split button press it as you turn around.
- Return on the same route but at a slightly faster pace — 10 to 20 seconds faster per mile than your previous pace. If you're running without a watch or haven't set the distance marker to know the miles on your route. Just push yourself a bit, but just enough to maintain a steady pace on your return mileage. Check your watch when you reach the start spot for the main part of your run, and begin cooling down. Your return time should be less than the time it took you to reach the midway point.
- Finish cooling down. Note your time mentally and see if you can beat it next time.