It sounds strange and counterintuitive, but believe it or not, the key to running faster is to run slow. In fact, most elite athletes spend 70% of the time training at Zone 1 or “low intensity.” They only spend 20% of time at Zone 2 or “moderate intensity,” and 10% at Zone 3 or “High Intensity.” Yet, the average athlete (non-elite) runs almost 50% in the “moderate intensity” range.
Why? They naturally push the pace to make their runs count more. However, this is more taxing on the sympathetic nervous system and running at this intensity day after day will lead to a burden of fatigue that is carried throughout the training process. This prevents them from getting as much out of their running as they would if they ran the same amount, but at a slower pace.
Zone 1: Light Intensity – average heart rate less than 80% of maximum heart rate.
Zone 2: Moderate Intensity – average heart rate between 80% and 90% of maximum heart rate.
Zone 3: High Intensity – average heart rate above 90% of maximum heart rate.
Running uses the aerobic energy system, which primarily relies on oxygen and fat for fuel. If you run too fast, your body will use carbohydrates instead of fat, which will not help improve your body’s ability to utilize fat stores for energy. This is critical during endurance races because glycogen (carbs) is a limited fuel source. If your body is not efficient at using fast for fuel, you will “hit the wall,” and run out of energy.
Slow running uses slow-twitch muscles and this increases the mitochondria (both in number and size), which allows your body to better utilize oxygen. It also increases the number of red blood cells and the amount of hemoglobin contained within them, giving your blood a more efficient oxygen-carrying capability. Lastly, it increases muscle capillary volume, providing more oxygen to the muscles.
Aside from the physiological benefits, slow running reduces chance for injury because it’s less stress on ligaments and joints. In addition, it allows you to get more out of hard work out days because there is less residual fatigue. Moreover, high intensity workouts take a large mental toll that may result in burnout or overtraining.
What can you do? Invest in a heart rate monitor so that you can track how hard you’re running. That way you can see objectively whether your intensity level is light, moderate or high. However, you need to know your heart rate training zones, which vary depending on age, body size, maximum heart rate and resting heart rate.
A simple calculation is to take 207 and subtract 0.7 times your age. For example, if you’re 40 years old (207 – 40 x 0.7 = 179 beats per minute.
Light Intensity: Under 143 beats per minute (under 80% maximum heart rate)
Moderate Intensity: Between 143 to 161 beats per minute (80% to 90% maximum heart rate)
High Intensity: Above 161 beats per minute (above 90% maximum heart rate)