If you think elite distance runners are spending every training session pushing themselves at superhuman paces, think again. In fact, while the mileage a pro puts in the bank each week is out of reach for most of us, much of this volume is done at paces that sound distinctly, well, human.
Why so slow? We asked world-class On athletes and coaches to explain how increased mileage at slower speeds can make you faster – and how we can incorporate it into our running regimes. Before we get to their run-faster recommendations, however, we need to understand a bit of sports science 101 – the difference between aerobic and anaerobic training.
Aerobic vs. anaerobic training
Aerobic activity is defined by the American College of Sports Medicine (ASCM) “any activity that uses large muscle groups, can be maintained continuously and is rhythmic in nature.” The key word in the definition as applied to running is “continuously."
Aerobic running is easy running at below 80% of your maximum heart rate. Running in this aerobic zone maximizes an athlete’s ability to burn fat as a fuel source. It’s running at the kind of pace where you think you could go forever. In the aerobic zone your body uses oxygen to power the muscles, fuelling them with both glycogen (carbohydrate stored in the muscles) and fat (its preferred energy source). With this power cocktail of fuel, your muscles can keep going. And going. And going.
Anaerobic training is what happens when you kick the intensity up a few gears. The ASCM defines it as “intense physical activity of very short duration, fueled by the energy sources within the contracting muscles and independent of the use of inhaled oxygen as an energy source.”
In plainer running terms, we are now out of the comfort zone and into the hurt locker at a pace we know we can’t sustain for very long.