A discussion today had me thinking about the recovery run. It's always a controversial thing - is it beneficial or are they just junk miles? I definitely have my opinions on the subject, just like anyone else. I'm not a sports medicine doctor, medical professional of any kind, nutritionist, or scientist...just a runner with some thoughts on the subject.
What's the Term "Recovery Run"?
To start, everyone has their own terminology, so let me be clear that in my head, a "recovery run" or "active recovery run" is a slow easy run, which may even include periods of walking, of 2-4 miles for many half and full marathoners following a training plan. Often used after a hard run or race where another moderate to hard running day is unadvisable.
What Many Think is the Purpose of the Recovery Run
Many people have followed plans with recovery runs or trained others to do them just because it's what been done. The belief has been that recovery runs increase blood flow to the legs which was additionally flush out lactic acid to decrease soreness and increase recovery. Runner's World had an article here that indicated using active recovery runs after a big race as a sort of "reverse taper" to keep total mileage base on track. I'm not sure I agree with that without an explanation that using the muscles for X amount of time is beneficial.
What I Believe the Recovery Run is for
Some sources now though emphasis that lactic acid is flushed out by oxidation which is a natural process and happens quickly after a hard run. Here's an interesting article about lactic acid and lactate threshold. I believe the recovery run is more for learning to run efficiently with legs in a pre-fatigued state. Active.com had a great article this year called "A Fresh Perspective on Recovery Runs" that explains this well, better than I ever could. I highly recommend reading it!
For me, running comes down to four areas: heart, lungs, brain (mental), and muscles (legs, core, etc.). Running easy on fatigued legs is good for that fourth area - leg muscles. A good training plan needs to balance the needs of these four things so that you are strong uniformly when you toe the start line. Active recovery runs to me are a way to get those muscles working smarter.
And yes, crosstraining could strengthen up and provide fatigue practice for leg muscles as well, but I think the practice should come with the sport you'll be using them in a fatigued condition at: running. It's like using an ellipical versus running. Yeah, they can both be helpful, but there's no substitute for the action of running. You wouldn't advise someone to do all their training on an elliptical and then run a marathon (generally), just as you wouldn't spend all your fatigued days cross-training just to go run or race in a situation where you need to run well on fatigued legs.
Every run has a purpose, but just because they are slow, doesn't make them junk miles. And personally, I don't believe any runs are "junk miles" or "wasted". As a tweep, @alamarcavada said, "Im not a coach but was a collegiate athlete.....There is no such thing as "junk miles." a mile is a mile."
Personal Use of the Recovery Run
Last year, I did an outdoor running streak of 63 days. And many of these days included recovery runs of 1-4 miles. During this approximately 60 days, I took 6 minutes off my half marathon time. And didn't even do much speedwork over this time. I believe the recovery run was a big reason for my success at that time. The purpose of the streak for me was very much the same purpose as that active recovery run. I felt like my cardio & pulmonary function was stronger than my mental toughness a bit and definitely stronger than my leg muscles. My legs just felt tired at the end of half marathons - it was preventing the "get up and go" to push hard that last handful of miles.
As a mom, doing lots of 13 mile training runs and generally a big increase to training mileage wasn't very possible, especially since I'm a slower athlete than many - that's a lot of hours of training for a lot less miles covered. The recovery run strengthened my legs and helped significantly in late miles of the race.
Another example is a good friend Paula who did a year long running streak and in the middle of it, on no longer than a 13 mile training run, she completed her first 50-miler. She credits a lot to the streak of just her body knowing how to continue to perform under fatigue. Plus she's just one mentally tough cookie.
Not Advised for All or at All Times
Since every run has a purpose, and this is for efficient use of muscles during fatigue, this run only works in combo with runs that strengthen all four important body parts (heart/lungs/brain/muscles). Relying on any one type of run is just a bad thing. So in your training plan, and in your personal experience of which parts are strongest and weakest, recovery runs may or may not be useful. Or what is useful at one time is not useful at another time in our running experiences. Like right now, cardio/lung function is very important as I recover postpartum.
Recovery runs aren't for everyone. One instance would be if you have bad knees or other medical issue where the impact could hurt more than help. And then, let's face it: runners are generally an intense Type A bunch - it's a stereotype for a reason. With that, some runners just can't run "easy" or even include walk breaks as needed to keep it truly easy. These runners will end up injured or on the verge of injury a lot of the time. Adding a recovery run for these people will just make it worse. Give them a rest day, hope they are religious to sticking to the exact training schedule, even though the day off may make them itch.
Where to Leave It
What do you think? Do you disagree? That's okay, but please explain why as well. I hope to learn something from other runners. Like I said when I started, it's just one opinion peppered a lot with personal experience!