Other recent research out of the University of Copenhagen showed similar results via a seven-week training program. After instructing a group of runners to reduce their mileage by 50 percent and add in interval training sessions three times each week, participants improved their 5K times by nearly a minute. This was all despite the fact that they were actually running less.
If that's not convincing enough, there's even a study that shows runners actually tend to enjoy intervals more than steady-state running. Perhaps too much LSD leads to mental staleness in the same way too much too much high-intensity training did. To be sure, balance is key.
A Simple Approach to Interval Training
Setting the science aside, Coach Jay Stephenson, founder of GoGo Running in Rome, Georgia, says it's all about common sense. "If you're trying to run a certain pace for 5K, at some point in the week you are going to want to run 5K race pace," he says. "If I want to be better at shooting free throws in basketball, I go shoot free throws, and I get better at it. It's the same idea in running."
Ken Rickerman, head coach for 5 Speed Running based in Southern California, agrees. "You can train all the energy systems with interval training, including stamina, threshold, strength and speed, and it also helps to improve mental discipline."
Luckily, understanding how to organize training can simplify the process and lead to real jumps in fitness and performance. When it comes to training intensity, the widely cited rule for endurance athletes is to do 80 percent of your training below your lactate threshold and 20 percent at or above it. Put simply, your lactate threshold is the intensity at which lactic acid begins to build up in your blood stream. It is important to teach your body to deal with that accumulation of lactic acid, but too much work done at that intensity will just leave you exhausted and possibly injured.