In Running, Fast and Slow - Part Three, we covered running fast and the importance of developing your maximum speed and overall potential. In this post, we'll cover the other end of the spectrum, the aerobic energy system.
The body's efficiency to produce energy out of fatty acids is a critical part of our endurance capacity. The goal is to maximize your output while still using fat as fuel. In recent years, the fitness community has shifted away from this approach, as short-term gains can come as a result of high-intensity training fueled by glucose.
However, our ancestors knew that the days between successful hunts were uncertain, but the fat stores they had developed could sustain them for long periods of time. See persistance hunting video below. Furthermore, a long hunt meant the body had to survive off fat reserves. Finally, bountiful amounts of sugar did not exist as berries and tubers did not pack the same amount of sugar as grains and refined sugar.
The point is, we have an existensively developed aerobic capacity and the potential to run for long periods of time at relatively high speeds is incredible. However, you have to train your body to stay in low gear and not shift out and start burning carbs for fuel.
Mark Allen, six-time Ironman world champion was a strong advocate for base training. He would do long buildups where he never let his heart rate pass 140bpm. For a good athlete, this is a very manageable pace. However, he was said to be able to maintain a 6:00min mile at this effort level.
Running coach Matt Fitzgerald has emphasized the 80/20 rule, whereby good endurance athletes have been seen thriving on low, easy efforts 80% of the time. Only 20% of training is spent doing hard, anaerobic work. For a good runner, this means that for every 100miles of training per week, only 20miles are at hard efforts.
A big part of running slow is to accept that slow is slow. Egos have to be left at the door, and your intensity must be stored away for your hard days.
Here are a few ways to get into the slow running game and build your aerobic system:
1. Wear a heart rate monitor to keep you honest and find out what speed to maintain while staying under 60% of your max heart rate. This is normally around 130-150bpm, but you can try the Mafetone Method as another formula.
2. Music and podcasts come in handy for these sorts of runs. You're simply trying to get some time in, so go slow and enjoy some tunes.
3. Run with friends who are slower than you. Your slow runs are a great time to socialize with friends who you might not be able to run with you at fast paces.
4. Experiment with a fasted run. Training at an aerobic level means you can tap into your fat stores for fuel while not feeling the same bonk that you would get when you run fast without much food in your system.
5. Believe in the long run. For many runners, Sunday long runs are a religious ordeal. Long and slow, these runs build the foundation to your running. Get in a long effort once a week.
Here's a clip of Dennis Kimetto running the Berlin Marathon in 2:02.57. This is a 4:41 mile, an example of speed and a huge aerobic base.
Here's a clip on persistance hunting (running your prey down until they get too tired) which some anthropologists claim have led to our species success and prosperity.