Go The Distance: 3 Reasons To Trade Intervals For A Long Run

These days, you hear a lot about high-intensity interval training (HIIT). In fact, it’s become so popular that the long run—once a staple of runners’ training regimens—has fallen to the wayside. It’s understandable: Long runs are harder to squeeze into a busy schedule and some coaches and trainers even argue that they’re unnecessary.

Exercise physiologist and online coach Greg McMillan, author of You (Only Faster), admits that high-intensity training has many benefits. “You can lose a lot of weight, get strong, and improve energy-system capacities,” says McMillan. He also acknowledges that high-intensity training can increase endurance, stamina, and lactic threshold. Still, he believes long runs are crucial to a well-rounded program. “If you run easy all the time, you’ll be missing the higher-intensity work you need to perform better,” says McMillan. “With runners, incorporating complementary styles of training is beneficial.”

And, he adds, you only need to run long once every week or two (although he says many runners fall in love with long runs and do them more often). “While it doesn’t fit into a hack-your-life, squeeze-it-in mentality, there is beauty in going out easy for an hour,” says McMillan.

Still not convinced? Check out all the ways long runs can help you go the distance.

1/ Build Running Efficiency
Better than any other training technique, going long teaches your body to burn less fuel at the same speeds, a concept known as running economy or efficiency. This is important because it allows you to run longer before fatigue sets in.

Here’s how it works: As you run, your body begins draining stores of easy-to-use glycogen (i.e. stored carbs). When those stores get low, your body starts to think about conserving energy by making every movement more economical and burning fat instead. Your large, slow-twitch muscle fibers (which enable long-distance running) start to fatigue and call upon your fast-twitch fibers (used for powerful, explosive movements like sprinting), which up until then have just been going along for the ride. This teaches them to act aerobically and get more endurance-oriented, which helps you to move more efficiently.

If you never opt for long, steady runs, you won’t effectively build running efficiency. “We know that high-intensity training improves the capacity of different energy systems, but it doesn’t do a great job at working on efficiency,” say McMillan. “If you’re training for a road race, you’ll perform better if you can be more efficient.”

 2/ Establish Aerobic Plumbing
Going long is also the easiest way to build your “aerobic plumbing.” In short, your body gets better at processing oxygen by increasing blood volume, building muscle enzymes, creating denser capillary beds, and adding bigger and more plentiful mitochondria (the energy-producing powerhouses of the cells). While a lot of intensity can yield similar benefits, it’s more stressful on your muscles, joints, and hormonal system, which is why going hard consistently might not be the best method. You’re also far more likely to burn out or get hurt. Going long gently builds a base that allows you to doing more work in the aerobic zone.

3/ Foster Mental Fortitude
A final benefit is honing the mental toughness required for higher-mileage events. “If you’re training for longer races, then you have to have the mental stamina that’s needed for a steady effort,” says McMillan. “If you always have a break [between short, hard intervals], you don’t learn that as well.”

Add Long Runs to Your Training Routine

How long is long? Start at a distance that you can comfortably finish while holding an easy, steady pace. “If that’s 30 minutes, do that,” says McMillan. Then, gradually increase the duration of your long run. “If you can go from an easy 30 minutes to an easy hour, you’ll see a gigantic boost in your overall fitness,” says McMillan. “Srength, mental clarity—everything will be much better.”

Tacking on another 30 minutes will help take your fitness to even higher levels. Unless you’re training for a marathon, feel free to stop there; the little benefit you’d get by going past the 90-minute mark doesn’t justify the time spent. “I think there’s a big value in an hour to an hour-and-a-half run for almost every type of runner,” says McMillan.

No matter how much you love running long, however, don’t go overboard. Always seek to strike a balance. In the end, the answer isn’t “or” but “and.” The best training includes both short, intense interval workouts and long, steady easy runs.

Jonathan Beverly

Jonathan Beverly is freelance writer and author of Your Best Stride and Run Strong, Stay Hungry. The former editor-in-chief of Running Times, he draws on decades of experience in the sport. He has run 26 marathons with a 2:46:04 best. Jonathan also coaches high school cross country.