Is a run of only 2 miles enough to get any amount of aerobic benefit?

Or better yet, take a trained person and have them do 2 miles per week and see how much they improve.

It depends. First, what do you mean by "any aerobic benefit"? Second, what kind of athlete are we talking about?

As far as we know, most of local aerobic adaptations to a short, easy bout of exercise are minimal. As for central aerobic adaptations, a two-mile run will have some effect. If you are very fit, the effect will be minimal, but all exercise has a minimal effect on the highly trained. They've reached a level where only VERY hard exercise will continue to produce adaptations. If you're a couch potato, 2 miles is a workout. (I'm going to assume we're only talking about easy runs here, as a hard 2-miler will have "some effect" for just about everyone.) Also, it's crucial to keep in mind that we simply do not know everything that happens in the body in response to exercise.

As for recovery, there are a lot of misconceptions about "recovery running." You are definitely not "flushing out lactic acid" or other waste products. That happens automatically and very fast after hard efforts. We do know, however, that after hard efforts, resting blood lactate is elevated (not because it hasn't "flushed" but because you produce more at rest when you're fatigued). Short, easy runs can more quickly bring blood lactate down to baseline, but it's unknown whether this kind of suppression indicates faster recovery. There is also the benefit of increasing GH hormone secretion so you're in an anabolic window for a larger percentage of the day (though 2-miles is short for this effect). This can also help with glycogen restoration and appetite suppression (not necessarily incompatible). Light runs also have an analgesic effect, likely reducing soreness even if the underlying damage isn't fixed any sooner.

My personal theory on recovery running is that it's valuable for maintaining full range of motion while tissue is being repaired after harder efforts.

Done them my whole life. For those of you following the Oregon System, 2-mile doubles is how you introduce doubles, then scale to 4 miles, etc.

Is 2 miles better than 0? Of course it is.

800, I agree with most of what you typed. Sure, a 2mile jog could be a workout for an untrained couch potato. I assume the OP is not since he is on LR talking about doubles. It is up to him to provide more info about the situation to decrease speculation and increase relevant advice.

Also, wanted to add(and i suggest you reading more into it) that the benefit of recovery from a short easy jog is mostly due to increased blood flow. Muscles/Tendons/Bones in a state of repair are craving fresh oxygen & nutrients and the easiest way to feed em is with increased blood flow from a light activity. Walk/Jog/Spin take your pick as long as its intensity & duration are small enough to not incur any additional damage. Pair this with properly timed nutrition and your many steps ahead of the next guy who just sat around all day after a workout.

Lydiard said a run as short as 15 minutes was with it. Also, doubling revs up your metabolism, which is especially good for beer gut runners.

…was WORTH it.

Minimum is 20 miles.

I'd honestly focus more on time and easy effort over miles/distance for your easy "recovery" doubles. I suspect you might initially find a sweet spot around twenty to twenty five minutes of nice easy running. ("Recovery run" is a misnomer. These runs don't enhance/speed recovery from previous training, but rather offer gentle training stimulus that doesn't interfere with recovery from previous training.)

Some other considerations to factor into whether the time and resources spent on doubles is ultimately worth it include total time getting changed, the extra laundry, showering, etc.

"Tempo" is in your screen name which suggests some familiarity with running and training. So hard to tell if this is a troll post. If you are brand new to running or recovering from a serious injury, 2 miles jogs are great. They may have minimal aerobic effect, but they will begin to strengthen your muscles and joints. Plus, they will get you into a successful habit cycle of morning running. With that base, adding speed and distance will happen with ease.

Personally, I find that I can’t get my heart rate up on only two miles easy. Ends up being around 6 minutes at 130-40bpm which I don’t find to provide much aerobic benefit to me. I do believe there is benefits to doing a 2 mile shakeout post workout to just get the legs moving.

Doubling 2 miles easy for mileage purposes is a bit odd to me, rather just tack that on to my morning run. Although, if you are trying to introduce yourself to doubles it can be a good tactic to work your way up. Additionally, it largely depends on how much mileage you are running. An athlete running 30mpw will have a higher marginal utility of those two miles than the athlete running 100mpw. So, I think that it can definitely help transition you into doubles and shake your legs out but it won’t be the reason you run PR’s.

Yes just turn that door know each day

There’s no reason to double unless you’re running like 70 miles/week right? So if you’re at that level, I would think 2 miles would be very trivial. I mean YEAH it’s better than nothing I guess, but you know what’s even better? Adding 2 miles to your morning run. For example, 8 is better than 6, and the aerobic benefit gets better the longer the run goes, so why cut it off at 6? if you’re not running 70 then I dont see the need to double.

Now, if you’re in some weird situation where literally you either double with 2 miles or you don’t get those 2 miles in then Ok do them but that’s the only reason I wouldn’t do singles. Again, unless you’re >70 miles/week but again I just can’t imagine a runner of that caliber talking about doing just 2 for their double

12' dispelled ~30y ago.

Damn, so you can do 2 miles in 6 minutes easily? Komen's got nothing on you..

I only run a couple days a year and stopped training probably 10 years ago. I can say with absolute certainty that 2 miles provides intense aerobic benefits. I'm talking heart rate up to 200 range.

So you feel super aerobically trained after your 2 miles? In superior shape then before you did it?

This is absolutely what i was thinking. Alot depends on your baseline.

If your goal is to be a 1500 - 5k runner it can work

But if your goals are half marathons and marathons, those are almost uselessly short runs.