You probably already know that running is a stellar form of exercise. It provides a host of health-boosting benefits, including improved heart function, boosted mood, and reduced risk of a bunch of chronic diseases.
But if you’re looking to maximize these gains, what’s the better pick: fast running or slow running?
On the one hand, fast running may seem like a smart way to bolster the efficiency of your sessions, allowing you to burn more energy and log more miles in less time. That said, slow running aligns with the zone 2 cardio trend, which promises ample cardiovascular benefit, plus minimized injury risk. So, it is a toss-up? Or does one reign supreme?
To settle the debate, we tapped two running coaches. Read on to learn what distinguishes fast running from slow running, the unique benefits of each, and the ideal breakdown within a training program, depending on your goals.
What do we mean by “fast running” and “slow running”?
“Fast” and “slow” are subjective terms. What may be considered fast for a beginner runner–for example, a 10-minute per mile pace–would likely qualify as super slow for an Olympian, whose fast may be, say, a 5-minute per mile pace.
So instead of assigning universal paces, a better way to think about the distinction is how easily you can hold a conversation as you stride. With slow running, your effort level should be low enough that you can talk no problem, Matt Campbell, a certified personal trainer and run coach at PRO Club / Bay Club in Washington state, tells SELF. “You’re not out of breath,” he explains.
For beginner runners, this often means taking regular walk breaks to ensure you maintain that ability to chat, Campbell says. Another way to think about it: at the end of a slow run, you should feel like you could have kept going, exercise physiologist and running coach Janet Hamilton, founder of Running Strong in Georgia, tells SELF. Slow running, she adds, should feel comfortable and easy.
If you’re someone who tracks heart rate during exercise, slow running typically falls into zone 2, which means your heart is beating at about 60 to 70% of its maximum rate, Campbell says.
On the flip side, fast running is pretty much the opposite of slow running. With fast running, talking is…not really an option, Campbell says. The run itself should feel hard and uncomfortable, and your heart rate will likely be 75 to 90% (or possibly more) of your maximum, Campbell says. This translates to zones 3, 4, and 5. No matter your fitness level, fast running will likely leave you feeling gassed.


