My experiences with training in Phoenix summers

Over the past several years I’ve seen a lot of posts in the Maffetone Method and Extramilest Facebook pages about summer training in the heat, and I’ve been wanting to share my experiences with training in the heat and what I’ve learned.

I live in Phoenix, Arizona where daytime temps from June through mid September range from the 100s to 110s and nighttime from the 80s to low 90s. In July and August we have high humidity that comes from the monsoon flow from the south, so it makes it especially miserable. I’ve trained in Phoenix summers since 1993 and have learned a lot. Every now and then I like to train for fall ultramarathons, which makes summer training very challenging. Luckily I live two hours from the high mountains of the north, so on the weekends I can escape to temperatures that are 30-50 degrees cooler and do my long 4+ hour runs there. But much of my training is in the desert heat.

When you go from cooler spring to summer heat, here is what I guarantee will happen:

1. You will slow down, probably 1-2 min/mi, or even more.

2. Your perceived effort will go up, along with your heart rate.

3. You will sweat a lot more, will require a lot more fluid and you will need to be much more mindful of how to manage the heat.

So what can you do about the heat? How do you train? Can you improve at all? Here are recommendations based on many years of experience:

1. Drink more fluid and along with that, more electrolytes. I like Tailwind and Precision Hydration. How much you need depends on how much you sweat. In fall/winter/spring when it’s cool I carry no fluid up to 2.5 hrs. For summer I drink 2-3 bottles (about 50 oz, about 1.5 L). Even on a 5 mi/8k run I take a 20 oz bottle.

2. When summer heat kicks in, I don’t compare my pace with what I did when it was cool. Higher heat means slower running and a higher perceived effort. So every June I set a new baseline to try and improve upon. Throughout the summer, I will repeat the same run or runs every 2-4 weeks and see if I improve at the same effort level compared to the baseline. I usually do improve in the summer, though it’s never as fast as what I do when it’s cool. But sometimes it comes close, though still it’s about 5 beats higher on average than when it’s cool.

3. I do much of my running well under MAF, about 10-25 beats under. If I try to run at MAF, I don’t last long, maybe 30 minutes at the most. If I try to push past that, the run becomes pretty miserable and can wreck the rest of my day. Running at a lower heart rate allows me to deal with the heat much better because I’m running at a lower effort. It’s far less stressful on my body.

4. I limit my summer runs to 2.5 hours at the most in the heat, and if I go that long I keep the effort very easy, like 10-25 beats under MAF. Any more than 2.5 hours is too stressful and makes me feel terrible throughout the day. I do most of my runs in the mornings, which are still quite brutally hot. I very rarely run in the middle of the day because I feel it’s too stressful on the body. If I do, I limit my exposure to 45 minutes.

5. In summer, leave your ego at the door. You will run slower, and that’s the fact of heat running.

6. If you are going to do intensity, do it indoors on an indoor track or treadmill. You’ll get a much more quality workout. You will remove the stress of the heat and can focus on maintaining a harder pace.

7. Maintain hydration throughout the day after the workout. Avoid junk food. I don’t watch salt intake because I sweat so much and my body seems to do great with it, but if you need to for medical reasons, listen to your doctor.

8. Adaptation to the heat takes about 4-6 weeks. Those 4-6 weeks are usually very tough mentally and physically. But during the latter part of the summer when the adaptation has taken place, although the running can still be uncomfortable, my body deals with the heat remarkably well as long as I stay on top of hydration and electrolytes. I usually see improvements in my aerobic running in the latter part of summer.

In #2 above, I describe setting a new summer baseline and trying to improve. Below is an example of a 10 mile very hilly run I was doing this past summer. It involved doing 6 summit repeats of the same mountain, essentially hiking/jogging up and jogging down at an effort level 5-25 beats below my MAF. Note the winter time at the bottom. Then note the baseline I set in June and the most recent I did it toward the end of August. At almost the same heart rate and effort I improved by 18 minutes in two months of the summer. And compared to winter it’s not much slower, with just an average heart rate of 4 beats higher in summer.

Training in the heat is a tricky process. It requires patience and it requires adapting your training practices. You can’t do the same training in the summer as you do when it is cool. You have to change how you approach the training and teach your body how to adapt. Your mind will play tricks on you because you’ll believe you’re losing fitness because you’re going slower, but trust me you are not losing fitness. As a matter of fact, when the cool fall weather comes, you’ll be amazed at how quickly you improve. Everyone reacts differently to training in the heat, and through experience you will find out what works for you.