Many of you will be racing the Phoenix Half Marathon and Marathon this weekend, so here are some notes about pacing. If you read nothing else, this article can be summarized thusly: These races are about how fast you can finish, not how fast you can start!
Half Marathon Pacing
The Phoenix Half Marathon course is slightly downhill, but mostly flat, so this course should be approached just like most half marathons.
- Run the first two miles at level 2 heart rate*.
- Run at the third mile at level 3 heart rate. Time this mile. Whatever pace you hold over this third mile is the pace you should hold until mile ten.
- Heart rate and perceived effort will start to drift upward as the race goes on, but hold on to that pace.
- At mile ten, try and lift the pace to level 4-5a for the last 5K or hold what you have.
- You should cross the line with nothing left to give, but not fading either. Your fastest miles of the race should come in those last three miles.
Half Marathon Nutrition
Eat 100-150 calories per hour (gel every 45-60 minutes), drink water as desired (17 ounces per hour on average). If you are a heavy sweater or plan on being out there for more than two hours, then take in at least 400mg of sodium per hour as well.
This is a downhill course which can tempt people into running too fast in those early miles. The name of the game on a downhill course is to bank energy not time.
- Run the first 13 miles at level 2 pace as though you were on flat terrain. Notice, the intensity is written as level 2 pace – not heart rate. Your heart rate may only reach mid to high level 1 when running downhill. Do not force your heart rate up into level 2 and run 30 seconds per mile faster. If you do this, you will over-stride on the downhill and, very casually put, beat your quads up. This will lead to muscular fatigue by miles 15-18. So, keep things ridiculously easy on the downhill and get ready to run well over the last 13 miles of the course.
- At mile 13, try and hold a solid level 2 to low level 3 heart rate.
- You can start to work a little bit once you are past half way. Your goal is to get to mile 20-22 feeling strong.
- At mile 20 (aggressive) or mile 22 (conservative), start your finishing kick. Over these last miles you may push yourself to level 3 and up. Again, some of your fastest miles of the race should occur in this last section.
- The key to the entire race is to save your legs and your energy on the downhill section. Many people will try and run faster on the downhill in order to get ahead of the goal pace and will have their legs shut down in the last 10K from muscular fatigue.
Eat 100-150 calories per hour (gel every 45-60 min), drink water as desired (17 ounces per hour on average), take in at least 400mg of sodium per hour.
Good luck and have fun!!!
*Heart rate intensity levels are determined through lactate threshold testing. In lieu of that, here is a key based on subjective words related to rating of perceived exertion:
|Lev 3||Somewhat hard|
|Lev 5b||Very hard|