"Junk miles" -- Any benefit?

Triathlon Forum
1

I’ve been reading through a lot of 2:30 marathon training threads on LetsRun, and what strikes me is how many “easy” runs these guys are doing to hit their 80-100 mpw targets. I’ve been conditioned to think of this a “junk” mileage over the years since transitioning from a pure runner to a triathlete.

My limiter is cycling. I’m a strong swimmer and runner (though don’t run to my potential in tris due to bike weakness). Would I benefit for doing lots of easy rides? For example, I could, theoretically, do an easy 30-45 min trainer spin every evening while my kid sleeps and wife does more work. And/or I could bike commute to work (about 30 min each way) a few times a week. Would there be any training benefit? A waste of time? Or worse, counter productive by detracting from my “key” sessions? If I add these extra base mileage rides, anything else to keep in mind?

My typical weekly schedule looks something like this, with key workouts in early morning:
M) Swim: Speed + Technique AM, “Prehab” PT/Strength PM
Tu) Hard run (hills or track)
W) Hard ride, optional brick run off time permitting
Th) Swim focus: Long/endurance swim, optional brick or PM run, time permitting
F) Long run
Sat) Long ride w/ mandatory brick run
Sun) Family day (which usually includes a light-moderate hike with our 1yo son on my back)

So with the framework above, I figure I could conceivably add some low Z2 riding Mon, Tues, Fri at a minimum and maybe also a 2nd Wed ride.

2

https://twitter.com/alan_couzens/status/1125453821038063616?s=21
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3

slow pace miles helps build your base. not every workout has to be all out… just the contrary. the more volume you get in the better off you are within reason, and the only way to get a lot of volume in is with a lot of, as you say, junk miles. if you smash yourself every workout your body will never be able to recover and you will get into over training.

4

more is more. if you’ve got the time and want to do more, knock yourself out.

5

Those aren’t junk miles… they’re building aerobic endurance.

How many hrs are you at per week? 2-3 runs/rides per week isn’t a ton. More mileage would almost certainly benefit you

6

Junk miles are when you spend too much time going too hard, not too easy.

7

https://twitter.com/alan_couzens/status/1125453821038063616?s=21

So it sounds like I’d be better off spinning out some easy miles on the bike for 30-45 minutes every night than reading Slowtwitch…

Anyone on here have success with this kind of strategy (bonus little 45 min Z2 rides most evenings)? In the past anytime I ramp running past ~50wmp, I’ve found all those little “easy” runs take their toll and I generally end up with knee problems.

Those aren’t junk miles… they’re building aerobic endurance.

How many hrs are you at per week? 2-3 runs/rides per week isn’t a ton. More mileage would almost certainly benefit you

I’m at 8-12 hours per week depending how much time I’m able to get on the bike on Sat. That’s generally the big swing factor. I find it hard to make more than 90 minutes in the AM on week days for my training sessions without cutting into sleep such that it’s detrimental to recovery. So that’s ~8 hours M-F with an occasional missed day due to work/life/travel, then 2-4 hrs riding Sat with Sun being for family adventures. But with this “evening spin” strategy, I could easily cram another 2-3 hours of riding in there with some additional PT “prehab” work after.

How long and how hard do I need these “easy” rides to be for them to have a training effect, what % of FTP? Is there really much an an aerobic stimulus from doing 2-3 extra 45 min rides each week at say 65-75% of FTP? Would you do them on the road bike or TT bike or a mix (i.e., whatever bike happens to be parked on the trainer that day)?

8

I have become a huge and I cannot emphasize huge enough believer in so-called junk miles high volume super low intensity.

9

Do the spin WHILST reading Slowtwitch 😁

I’ve defo seen far-fitter-and-better-than-me guys blow up on IMs because, despite being very good runners, they’ve not put the miles in on the bike.
Their approach of ‘just get to the run then I’ll be fine’ has been shown to be very flawed, because they’ve been too knackered off the bike to run well (or even finish).

As the advert goes, ‘every little helps’.

Also a guy I know moved from para tri to para cycling (leading to Tokyo).
Interestingly the British Cycling approach is LOTS of zone 2 riding for a ‘base’ , and Zone 5 efforts. And nowt in between.
Quite different to the triathlon ‘threshold’ based stuff.

10

Gotta be more specific about separating running from cycling, since the impacts are so different… Pretty much no such thing as junk miles running for our purposes; more volume is almost always good, but most of it has to be really easy or it’s just tempting injury. Even a seemingly short run is worth something if you can get up to running 5-6 days/wk.

Biking is not really the same, since a lot of easy miles on the bike relative to easy miles running simply take up waaay too much time. So yes, it’s possible to lard your schedule up w/ ‘junk’ biking miles, not in the sense that they’re a total waste for conditioning but that they take up more time than they’re worth compared to swimming or running. I had better results with trying to ride longer when it was time to ride longer (like maybe stacking 2 long-ish rides back-to-back on a weekend instead of just one really long ride), and then try to cram in more intensity during the shorter time chunks available during the week. Where I live, that meant being able to go bang out a quick hill ride now that it’s light long enough after work. I know some folks like to dial in work more specifically using a trainer & PM, etc, but I still prefer to cede some control for the freedom of actually enjoying the outdoors.

Looking at your sample sched, 2 rides/wk ain’t much, so in that context adding a 3rd/4th ride shouldn’t be ‘junk’ ~ maybe decouple the long run & long ride from consecutive days so you can try to get a little more cumulative effect of loading a bit more bike volume on Fri/Sat or try to squeeze something in early on Sun before the rest of the fam gets going, and then try to mix in a 2nd shorter/harder ride sometime during the week. I ended up finding value in more bricks, not for specific training effect but just the economy of only gearing up & down (leaving the house, cleaning up, etc) half as much.

11

Just my personal experience. My knees can’t do 50+ mpw marathon training anymore. I’ve backed it down to 30 easy mpw for the last 2 years. Zero speedwork. Very few long runs. But, I’m cycling (mostly indoors, and on a properly set-up dinosaur spin bike) 200-300 mpw. About 50-50 junk miles/quality. I ran my 41st marathon last month, and easily ran my 10th BQ. There’s no way in hell I could do that on the running I’m doing.

12

If the primary benefit is to build your aerobic base, another option is to add more swimming. That allows you to build a stronger engine without the wear and tear of weight bearing activities. I think it depends heavily on the person’s tolerance (physically) for more running, but in an n=1 example, I’m running as fast as I ever have (I’m in my mid 40s) and running less than I ever have. But I’m swimming 4-5 days per week. That’s definitely been a big part of it

13

I define “Junk Miles” as miles that don’t target you needs and require more recovery than easy runs do.

With that said, if a person is time limited and can do every run (or workout) they have scheduled with minimal recovery then they can run faster on their easier runs.

14

My typical weekly schedule looks something like this, with key workouts in early morning:
M) Swim: Speed + Technique AM, “Prehab” PT/Strength PM
Tu) Hard run (hills or track)
W) Hard ride, optional brick run off time permitting
Th) Swim focus: Long/endurance swim, optional brick or PM run, time permitting
F) Long run
Sat) Long ride w/ mandatory brick run
Sun) Family day (which usually includes a light-moderate hike with our 1yo son on my back)

You’re currently biking twice a week. If you bike more than twice a week you’ll get better. If you bike more than twice a week with the correct balance of intensity you’ll get even better.

15

with the limited cycling, I can’t see it doing any harm to get more time on the bike and maybe use it to work on position and cadence/speed work.

Whether you are getting any significant fitness from sub 1-hour easy rides is probably debatable. There is lots of data that says long and slow works, but I’m not aware of much data saying the same thing about multiple short easy rides across many days. It might be out there, just haven’t seen it. Based on what I understand, you probably aren’t building significant aerobic fitness 45 minutes at a time, but any time on the bike would probably benefit you in other ways. Just because a ride isn’t building fitness doesn’t mean it’s “junk miles”.

16

I’ve been reading through a lot of 2:30 marathon training threads on LetsRun, and what strikes me is how many “easy” runs these guys are doing to hit their 80-100 mpw targets. I’ve been conditioned to think of this a “junk” mileage over the years since transitioning from a pure runner to a triathlete.

My limiter is cycling. I’m a strong swimmer and runner (though don’t run to my potential in tris due to bike weakness). Would I benefit for doing lots of easy rides? For example, I could, theoretically, do an easy 30-45 min trainer spin every evening while my kid sleeps and wife does more work. And/or I could bike commute to work (about 30 min each way) a few times a week. Would there be any training benefit? A waste of time? Or worse, counter productive by detracting from my “key” sessions? If I add these extra base mileage rides, anything else to keep in mind?

My typical weekly schedule looks something like this, with key workouts in early morning:
M) Swim: Speed + Technique AM, “Prehab” PT/Strength PM
Tu) Hard run (hills or track)
W) Hard ride, optional brick run off time permitting
Th) Swim focus: Long/endurance swim, optional brick or PM run, time permitting
F) Long run
Sat) Long ride w/ mandatory brick run
Sun) Family day (which usually includes a light-moderate hike with our 1yo son on my back)

So with the framework above, I figure I could conceivably add some low Z2 riding Mon, Tues, Fri at a minimum and maybe also a 2nd Wed ride.

I comment on these types of questions a lot because my training observations are entirely at odds with the current recommendations. I’ve been listening to a lot of top coaches discuss volume and intensity, both in podcasts and in youtube videos. Without having hard numbers from which to pull, they usually estimate that their athletes are between 85 and 95% easy (aka, junk) efforts. These are mainly olympic tri distance coaches.

This is utterly baffling to me. First, my ~10 years of garmin data robustly confirms that when I start chasing distance or time-spent as a metric for prescribing my sessions, my performance plummets, both in the run and on the bike (swimming, not so sure). I can give hard numbers as examples, for context if anyone is interested, but suffice it to say, I’m not back or middle of the pack. Second, endurance performance is bounded by two primary variables: VO2 max and the percent of VO2 max that you can maintain for the duration of the effort. It’s not disputable that higher intensity training produces more robust stimuli for both of those factors. In other words, run for 30min easy or hard; the hard effort will product the greatest stimulus for acclimation. So what is the mechanism whereby easy efforts contribute to enhanced performance? It’s not enhanced fat metabolism; our capacity for peripheral lipolysis already exceeds our capacity to deliver it to the muscles. My best guess (and what seems to be suggested by these coaches) is that it’s a compromise: predominantly high intensity efforts are largely unsustainable from a psychological and physiological platform. And if you have burned-out or sick athletes, those are non-exercising athletes. So the next best thing is to pile on tons of volume, sprinkle in some intensity, and keep everyone healthy and exercising. There’s plenty of published observational data to suggest that this approach works, but to my knowledge, no one has even proposed a mechanism attempting to explain the direct superiority of easy vs hard.

Honestly, every time I get sucked back into focusing on miles and time (like I am now), my FTP and 10k just absolutely crash. It’s so demoralizing. My best run performances have come from less than 10 training miles per week and my highest FTP has come from doing nothing but 1- and 3-min intervals a few times per week, which ends up being the equivalent of less than 25 miles and maybe two hours of riding. I don’t know. Volume doesn’t work for me, but here I am, trying it again.

17

with the limited cycling, I can’t see it doing any harm to get more time on the bike and maybe use it to work on position and cadence/speed work.

Whether you are getting any significant fitness from sub 1-hour easy rides is probably debatable. There is lots of data that says long and slow works, but I’m not aware of much data saying the same thing about multiple short easy rides across many days. It might be out there, just haven’t seen it. Based on what I understand, you probably aren’t building significant aerobic fitness 45 minutes at a time, but any time on the bike would probably benefit you in other ways. Just because a ride isn’t building fitness doesn’t mean it’s “junk miles”.

I hear this sentiment around here a lot, but I’m never quite sure what is meant by it. How are we defining aerobic fitness? It’s likely either your top-end capacity to liberate ATP from oxygen substrates or it’s the rate of ATP liberation you can sustain (via oxygen substrate) for a defined duration. Whichever you choose, there’s plenty of empirical data to demonstrate that the underlying mechanisms that determine these end points can be substantially bolstered with less than 45 minutes of training. Is more better? Maybe. But you can certainly induce powerful training acclimations in less than 45 minutes.

Edit: My apologies. I definitely didn’t mean to seem like I was singling you out or anything. I just wanted to reply generally to that sentiment which seems to be pervasive.

18

For running I think of it in terms of how many high quality miles you are doing. There are only so many tempo and track miles you can do. After that it needs to be recovery miles that help you by conditioning your legs to more pounding and getting used to running, not adding massive amounts of stress. This means taking it way easy. Most people run too little too slow. If you run low volume (tri) much of it has to be fast. If you run a lot (runner) you need a lot of it to be easy for survival. My opinion.

When I do 40 mpw for tri training, more than half of it is quality miles, track workout with 10k of intervals, moderate tempo, and progression/long run each week. If I am doing only running (a decade ago), the quality is similar with an extra track workout, but every single day is filled with running miles that are beneficial but dont hurt the workouts that matter. Think of it of upping your hard running slightly and replacing every single bike and swim workout with easy miles.

You simply cannot be near your potential for a single sport while doing triathlon. As a data point, I did a track 5k a minute slower than my pure runner pr right before having a breakthrough run at Oceanside. Similarly I am sure I would be way better at biking if I only did that. Pick what you want to be good at. Shame we can’t do it all.

19

I think about training as a process of reverse engineering.

The goal is to be able to do a small number of long AND hard training sessions and recover from them.

But how do you prepare to do that?

Answer- You must first do regular long workouts and separate regular hard works and recover.

But how do you build the fitness to do that?

Answer- you build on what you did in previous weeks, and you have an abundance of moderate workouts.

To summarize- short easy workouts provide the fitness to do long and hard workouts. Long and hard workouts provide the fitness to occassionally do workouts that are both long and hard.
And that provides the fitness to race.

20

Statements about junk miles are the sort of thing that clueless people write on FB. Like others have said, you can’t go full-throttle or make all your sessions ‘quality’ threshold work; unless you want to just train that system of the body and only train a few hours a week. ‘Base’ miles are still important to build the aerobic system, condition the body (important for Long distance) and link those harder intensity workouts.