Long Slow Distance Saturdays

Saturday miles should be completed at least 45 to 90 seconds SLOWER than your race pace.

Slow running builds your endurance. You are training your body and your brain to tolerate the distance you will cover in your half or full marathon. Long slow running will teach your body to burn fat for fuel. Carbohydrates are essential fuels but they burn quickly and are used up first. Even if your presonal percentage of body fat is low (I wish mine were) you still have enough to fuel your efforts for many hours. BUT you have to teach your body to use it. Research has shown that running at lower intensity for long periods maxmizes the body's ability to burn fat for fuel. This article explains this fairly well. It's full of a lot of numbers and science but stick with it and you'll find the english as well. Here is an excerpt that summarizes the process.

Conversely, when you teach your body to rely on fat for fuel, your combustion of carbohydrates goes down, thus "sparing" carbohydrates. This benefits performance in endurance events. You become very fatigued when you run too low on carbohydrates. We store only a very limited amount of carbohydrate (glycogen) in our bodies. Compare this with a relatively unlimited supply of fat. Even an athlete with only 6 percent body fat will have enough fat to fuel exercise lasting for many hours. When you use more fat, you generate more energy and your carbohydrate supply lasts longer.


Follow the principle of specificity. If you want to teach your body to use more fat for fuel, then create training conditions that generate high fat metabolism. Your body will eventually learn to prefer fat.

In short, teaching your body to burn fat for fuel delays the onset of fatigue and hitting 'the wall' during your race and training. Running slow also allows your muscles to get used to the distances as we add miles from one week to the next. You should finish each Saturday long distance feeling accomplished, perhaps tired but not ready to drop. If you go home needing a nap you probably worked too hard. You should feel like you could go just a bit more if you had to but happy that you didn't have to.

The challenge is that running slower goes against our competitive nature. Even back of the pack runners typically run their training runs too fast. At the beginning of our run we are full of energy and going slow feels weird. Left alone, most of us would start too fast. So at USAFit/Philly we assign a pace leader to a group of similar paced individuals. The pace leader will do his/her best to keep the group at the proper training pace. Each member of the group can play a part in this effort as well. Work together to keep the pace down and spirits up.

A common question is "Won't running slow make me a slow runner". Yes, if that's all you do. That is why it is important to follow the FULL weekly schedule. Completing tempo, hill and speed workouts during the week will give you the strength and speed you seek.