One of the most common debates in training is whether it is better to base workouts on time or distance. In the world of ultra races, running based on time is an accepted approach, even in competition. (In 24-hour races, the runner who covers the most distance in the allotted time wins.)
The popularity of using distance to gauge a workout might be due to the fact that most races are defined by their length. You’ll be hard pressed to find a training plan that doesn’t include specifics such as 400-meter repeats, a 2–4-mile tempo run or a defined-distance long run.
In hopes of shedding light on some of the differences between running based on time and distance, a study published in Medicine & Science in Sports and Exercise tested 38 children in a 750-meter run. While most of us are more experienced runners than these children, the results provide an interesting perspective on how our adult training practices come into play.
First, the researchers had all 38 kids run a 750-meter time trial as fast as they could. Then they split them into two groups — one ran the 750-meter trial again and the other ran for the amount of time it took them to run the first trial. For the former group, they managed to cover the 750 meters in about the same amount of time. The other group that ran based on time, however, covered significantly less distance than they did the first time.
The researchers concluded that this was likely a result of the fact that time cues are less tangible and therefore make it more challenging to judge pace than information based on distance where, for example, you can actually see the finish line. Give yourself a concrete distance to complete for your next all-out workout or time trial and you might just go a little faster.
In addition to noting a difference between time and distance, the study reveals that each approach has its own function depending on the desired outcome. “There are different times in the training cycle and the season when an athlete needs to train on time or distance,” explains Jennifer Harrison, a USA Triathlon Level 2 Coach based in the Chicago area.
She suggests that running based on time comes in particularly handy when an athlete is in the offseason, putting in base mileage, or is returning from an injury. “That way, the athlete can log miles without worrying how fast they are going,” she says. “Mentally, that helps a ton.”
As the season gets into full swing, Harrison usually prescribes more workouts based on distance. “That’s when we start focusing on run specificity and getting athletes on the track to do intervals with time goals that are specific to their upcoming race,” she says. While time-based runs are just as valuable, a workout based on distance can give important feedback regarding an athlete’s fitness level and projected race times. There’s a time and a place for each and the right combination may just elicit better competitive results.
Recovery run: Turn off the data and just enjoy the run. These runs are about letting your body bounce back from a previous workout.
Fartlek: By their nature, fartleks are easier to base on time and help with internal pacing.
Tempo: These types of workouts are key to helping an athlete learn pacing based on feel.
Intervals: Intervals on the track or road give you some of the best information on how an upcoming race will go and what you need to work on.
Non-Workout Regular Runs: This will help you gauge progress and how much distance you can comfortably cover in a specific amount of time.
Time or Distance
Long Run: In the off-season or when you’re recovering from an injury, base the long run on time. If you’re mid-season, go with distance to ensure you get in the miles necessary for the distance you will race.
This piece first appeared on triathlete.com.