For the first 15 (or so) years I ran, I laid out all of my training plans in miles: 3 miles today and 6 miles on Saturday.
But in the last 5 (or so) years, especially as I’ve been doing more trail runs and incorporating more hill work into my training, my training plans increasing include runs based on time: 30 minutes today, 45 minutes tomorrow.
And it isn’t just my plans, I’m increasingly seeing off-the-self training plans include time-based runs.
This begs the question- Which is better? Which is ‘right’?
Spoiler alert: like pretty much all things in life, the answer isn’t always one or the other.
For the second time in as many weeks, I’ll pull out my lawyer answer: it depends.
It depends on you, the course you are running, and your goals.
Running by Time
Running by time puts more focus on the effort than on the outcome.
They are easy to schedule
One strictly practical reason to run by time is you know exactly how long your run will take.
If you are running for 30 minutes, you know that’s how long you need to block off on your calendar. Great for fitting a run into a busy schedule.
It gets you in touch with what your effort feels like
I have several running clients who get a little ‘obsessed’ (their words) with pace. One (in particular) knows she shouldn’t focus on her pace. She knows that some runs should be ‘hard’ and others ‘easy,’ but she just can’t stop focusing on time, meaning her ‘easy’ runs usually aren’t all that easy.
Enter: naked runs. Leave the GPS as home and run ‘easy’ for 30 or 45 minutes.
What’s her pace on an ‘easy’ run? Who knows, and it doesn’t matter.
But don’t think listening to your body means you’ll only go slower.
Without a preconceived idea of what an ‘easy’ or ‘hard’ pace is, on some days you’ll feel amazing and run faster (not that you’ll know it, since you won’t have a watch).
They protect your ego
I can always tell new trail runners at the start of a trail race. They are talking to their friends at the start: “My last [flat, road] 5k was at a 8:30 pace, so that’s what I expect to do today [on this super hilly, technical 5k].”
Oh, sweetie, you are in for such a shock…
External factors can have a huge impact on how fast you run. If it’s super hot or humid, when you are coming back from injury, or if the course you are running is insanely hilly, your time will (and should) be slower than the same distance on a flat course in perfect conditions.
This slower time is to be expected. If seeing that slower pace could be a blow to your ego, run by time instead.
It’s harder to plan routes
When picking a route, there are endless options. You may not always know which one will take you 30 minutes to run.
My time-based runs tend to be out-and-backs for just this reason. Boring, maybe, but predictable, which is a good thing in this case.
It’s harder to tell if you are race ready
Unless you are training for 6 or 12 hour race, races are a specific distance. If you are preparing for a race using a time-based plan, the plan needs to be specifically geared for you.
I’ve seen time-based marathon plans that top out with a 3 hour long run. That’s fine if you are faster runner, since that’s a pretty good percentage of the marathon distance for you. But if you are a 5 or a 6 (or longer) hour marathoner, that 3 hour long run is a much smaller percentage of the distance you need to be prepared to run.
Pro or Con (depending on you)
There is no incentive to push yourself to the limit, since you’ll be running the same amount of time regardless of how hard and fast you push.
This is great for runners who tend to go too hard, but bad for runners who don’t push themselves hard enough when left to their own devices.
If you tend to go easy on yourself, you need to have the self-discipline to run hard (if/when your time based run calls for that).
Running By Distance
Running based on distance is more specific and measured.
You know if you are (or are not) race ready
When you train by distance, you’ll have a better sense of when you are race ready.
You know what race distances are realistic for you if you are running those distances in training.
You know what a particular pace feels like
Especially if you have a goal race time, it will benefit you to get your body used to what that pace feels like, so you can nail that pace on race day.
It also goes the other way: if you know what pace(s) you are running in training, you can more easily tell what time-based race goals are realistic for you.
They make your Garmin even
This may or may not be legit, but I can’t deny it’s an issue for the more OCD runners among us: it makes Garmin/Strava miles even.
It really bothers some runners to end a run at a random distance. If you run by time, you may hit your time with an random distance on your Garmin. Distance based runs? Always even.
A total non-issue for some runners, a huge factor for others.
You may push too hard
Can be tempting to push too hard, especially on easy run days.
It can be hard on the ego if your easy pace runs are at a slower pace than you are capable of running (which, BTW, easy runs should be), especially in this day and age when others will see your time on Strava. You may fear that others will **gasp** see that ‘easy’ pace run of yours on Strava and judge you.
I’ve seen more than a few Strava runs where the runner titled the run to make it very clear it was an ‘easy’ run at a ‘recovery’ pace, lest anyone think of judging them.
It can be hard on your body and mind
It can be tough to always have to hit a specific mileage, regardless of how you are feeling or how the run is feeling.
If you are a rule follower (like I am) distance based runs can leave you unsure or uncomfortable adjusting a run based on the circumstances, which can lead to all-or-nothing thinking about getting a run done.
So what’s best?
I already tipped my hat to my opinion: neither is always right or always wrong.
My advice (what I do personally and for my clients), is to put both on the calendar for different purposes:
- Trail runs or hill repeat days: time
- Coming back from injury/illness, or when you aren’t feeling 100%: time
- Easy run days: time
- Runs for race-specific or pace-specific training: distance
- Every day runs: A little bit of both to keep it interesting