“Everyone loves the idea of a single silver bullet solution, but it’s not that easy,” Sherry says.
Supporters of traditional high-volume run training are understandably skeptical about HIIT. High-volume running has been the training cornerstone of millions of runners since Lydiard developed it and turned a group of New Zealand runners into world-beating superstars in the late 1950s and early 1960s.
“The first response [from HIIT proponents] is it makes you run faster but what does it possibly do negatively?” questions Daniels. Unfortunately, there can be too much of a good thing and there are drawbacks of HIIT, particularly the potential for injury, he says.
Out-of-shape runners looking for a short workout that also offers high gains would be especially drawn to HIIT; however, they are not the ideal HIIT candidates in the same way that barefoot running isn’t appropriate for new runners or those who have been wearing substantially cushioned shoes for years.
“The bad thing about high-intensity work for someone who is deconditioned is they might injure themselves,” Codish says. This can be remedied easily with a more gradual approach that begins with lower-intensity workouts and graduates over time to adding in more intensity.
“I don’t think pitchers are throwing 100 mile-per-hour fastballs on the first day of spring training,” Daniels says. “I assume they’re throwing fairly comfortably and build up to the faster stuff. It’s the same for running. You can’t start doing fast stuff on the first day of practice.”
The same approach works for even the most conditioned athlete. A fit runner may easily handle slow miles; however, adding in a new stress such as HIIT is strain on the body and can result in injury. Gradually adding HIIT workouts into training over several weeks helps the body to adjust and become comfortable with the new training stimulus.
Adding HIIT to a training program can also put a mental strain on many runners. After decreasing his runners’ mileage to accommodate the added stress of HIIT, not all of McLaurin’s runners were thrilled.
“It plays with their minds when they see their weekly mileage go down a little bit,” McLaurin says. “But they need to understand that lower mileage doesn’t mean lack of effort.”