Should slower runners train by time instead of distance?

Short answer, yes. Your body doesn’t know anything about distance, just exertion and time. In extreme cases, the workout might be a total disaster or lead to injury.

Long answer: it depends. For some people it’s motivating to deal with distances in workouts, since that’s what race. I will do timed intervals if the terrain is variable and hilly, but I like knowing I’m doing 1km repeats or mile repeats for the mental aspect on other days, even if when I’m fitter those intervals might be 30sec shorter.

You're 100% right. Time at a given effort is what matters. Sometimes everyone can fit into an acceptable zone. For example, for anything under 800 @ 3200 pace, even my slowest runners are done in around 4 mins. They get longer rest and a reduced number of intervals, though.

For other stuff, the workout needs to be modified for the slower runners. I tend to follow Jack Daniel's recommendation of keeping 3200/5k pace intervals at 5 mins or under, which means that you need to be a 15:40 5k runner to do miles at 5k pace. Anyone else would do 1200s or time-based intervals instead.

For some workouts, I have the whole team do time-based intervals together. For example, one of our early race effort workouts is 1 min on 1 min off on a grass field. The switch directions so everyone regroups after each interval. Some kids are running 300m while other kids do 150m. We also do 5 min tempos with 1 min rest on the track.

Everyone should. Fisher running 100mpw is different than me doing it. 100 x 6 min = 600 mins. 100mpw x 8 = 800 mins. That is extra 3 hours and 20 minutes per 100 miles.

It’s not just slow runners, all runners should train by time and a lot of pros do and before gps watch most people did just that.

However those with easy access to tracks become lazy and just run laps as it’s easy to do. So do 4 and half laps then just the 200m and repeat and we wonder will regressed at distance running

Like others have said, your body doesn't know distance. It only notices effort and time. Everyone should train by time at the very least on their normal run days. Miles are irrelevant.

However, everyone should use both distance AND time during workouts. Doing that allows you to track progress and gets you ready for races

Yes, by time. Your example is a little extreme though. I'd have that runner just doing mileage and some strides - and running by time with strides by number.

I prefer running by distance. Running by distance I find I don't worry about the time and just run and enjoy myself. Running by time, I feel like I'm racing the clock to get as much mileage as I can in that time, and I tend to feel like I failed if I don't finish my goal distance in that time.

As a mental exercise, what if races were for distance in a given time, rather than time for a given distance? For example, in the 4 minute race, Bannister would be the first to make it all the way to the mile marker. Or, "What's your PR for the 5 minute race?" "1753 meters."

Would that make training more applicable across the board? Would everyone do "5 minutes at 60-minute race pace," (which would be equal effort for everyone), instead of mile repeats at threshold (which would be more work for a slowpoke)?

It should be the opposite of how you feel. If you train by distance, you could feel like if you rush the pace you will be done sooner, compromising your easy running days and overtraining. I'd say this is what most people do. And why are you trying to pack in as many miles as you can? The goal of a run is to hit a certain stimulus. Distance isn't something that stimulates adaptation. Effort level is. Time is.

Training by time allows me to know there is no shortcut to this easy run. I will be running for 40 minutes no matter how fast I try to make it go. This allows me to go slow and settle in mentally and physically on my non-workout days.

Not really on topic, but I think these would make great events for spectators. In cycling you have the hour record as a TT, but actual races for a set period of time would probably be tactically quite bizarre. Like the elimination mile… I think having some different formats livens things up and gives different physiologies and racing styles an interesting look.

Time is the way to go, I think. Imo the most important variables are consistency and frequency. So it's better to plan for say, 6 days per week for 20 minutes of good aerobic effort vs. trying to pin down arbitrary mileage totals which might have you running drastically different amounts every day. In my experience the latter leads to burnout whereas the former is easy to wrap my mind around and gets me out the door on a consistent basis.

Just about every study I have ever looked at on interval training is done on a time basis. At the end of the day it really doesn't matter if you are doing 5 x 5 minutes or 5 x mile(assuming you're doing both reps at 5 min pace). It's about x intensity at y duration.

Older runners should.

Trying to keep my head above water mileage wise with unrealistic goals, realize time was far excessive and did much to cause my injuries

Hot take: the guy running a marathon in 2.5 hrs and the one doing it in 4hrs aren’t even doing the same event.

Event A: how far can I run in 2.5hrs

Event B: how far can run in 4hrs

Same logic for other events. Training plans should change accordingly.

Just shrink the distance for a slower runner. A fast person running 2k repeats is a slow person running 1k repeats. One isn't better or worse. The fast person could do 6 minute repeats instead of 2k repeats. That's like asking if you could lift more if you keep track of your sets in pounds or kilograms.

I don't think a 30 minute 10k runner and a 55 minute 10k runner are using the same energy systems during their races. If these 2ks are at 10k race pace it seems as if it would make sense for both the fast and slow runners to do the 2ks at race pace even though its working a different system because they will be using different systems in the race.

If the training plan is designed for a fast runner to run a sub 30 10k and the slower runner is using it to run a sub 30 5k, then it would make sense to go off time.

I think it's less about if someone is a new or veteran runner and more about their personality when it comes to running.

I see people who tick off 7:30/mile on a 12 mile run with almost no variability but I see others that will progressively get faster as the run goes on to "end it." Example 1 can go by mileage, example 2 should go by time.

The most important stimulus is distance though. 6 miles in 36 minutes is more beneficial than 5 in 36. If you have the discipline to run your easy runs correctly, I don't think it makes any sense to run on time.

For threshold yes, but for race paced intervals no (unless overall mileage is a limiting factor for the marathon).

We typically define threshold (or LT2) as 1 hour pace, therefore, we probably want to stay with a time metric in order to get an accurate picture of the overall training stress. 5 x 2k at threshold might be the ideal amount for someone running each repetition in 6 minutes, but for someone running each rep in 8:00, it's likely too much. 5 x 6 minutes at threshold is therefore a better equivalent.

However, when it comes to races, we don't race for a set time, but rather a set distance.

If you prescribe 1k repeats at 5k effort, you might think that someone running 4:00 per rep is doing a much harder workout than someone running 3:00. However, the relative intensities also scale. The 3:00 runner is training for an all-out 15:00 effort, which is much closer to vo2 max than the runner training for a 20:00 effort.