Science/physiology behind Rest Days?

BYU does it.

What more scientific evidence do you need?

Rest days are probably less important the lighter and weedier the athlete is, also less important being the more optimal a body composition an athlete has given their genetics, and finally, given the recovery and sleep of that athlete.

If you have extra muscle or fat mass to carry, if running makes your body sore and worn down, if you suffer sleep issues - you probably will find a recovery day very important.

I'm way fatter and heavier than I was when I was a distance runner. I'm 29. My vertical jump is higher than it ever was when I was a runner, but I can't handle any kind of running volume right now. It isn't just because I'm older, but primarily because I weigh 35-40 lbs more than when I was at my 5k personal best.

It is that, and the fact that I built up very slowly.

basically, your answer is that it depends on too many factors to say for sure; and if you're asking the question, it probably means your recovery hasn't been optimal and you'd probably benefit from the rest day.

if your performance declines for more than 3-4 weeks, and/or you develop injuries, you need to assess your rest and training volume, 100%

Is your goal to be easy on your body or to get the most adaptation possible? Pretty much everyone believes in hard/easy. The question here is how easy should easy be. A full rest day or is it okay for slow running? Plenty of people have run fast on either so the take away isn’t is unlikely to matter much.
And there are stuff like every 2 or 3 weeks or cross training on the off day to get the aerobic work without the mechanical stress.

When you do intense exercise, you damage muscle cells and they grow back stronger and better adapted. This process takes ~36-48 hours. Not taking rest/easy days means you never allow your muscles time to actually adapt to the intense workouts (if you somehow manage to avoid injury).

Norwegian singles/doubles are only somewhat related to this. They both seek to maximize sub-threshold intensities because you can typically get away with high volumes of it compared to something like VO2 work, which provides strong adaptations for distance runners from 1500-marathon. Doubles work because muscle fatigue also takes some time to set in - so you can get even more stimulus per rest period.

Adaptation is all about how much you can do specific to your goals given adequate rest for the body to physiologically adapt to each stimulus.

No idea what the two psychos above me are yapping about.

I think that rest days make perfect sense. If you can hit your mileage goals, I don't think it's relevant whether you take 0 days off or 3 days off a week.

There are going to be people out there that sell or promote certain coaching methods that will claim things like "rest days" are going to stop you from making gains.

They won't, deciding that rest days are bad for you and not taking them when you probably should is a much worse outcome than feeling a little weird on Tuesday because you took Memorial Day weekend off.

Having been someone who converted to nsm from a traditional running schedule with a lot of intensity at certain times and downs weeks, with often a day off scheduled a week , I can tell you the difference is night and day.

Why that is, I don't know. But I haven't had a day off in 6 months now and feel awesome. I used to have most Tuesdays off and used to feel terrible , a lot of the time.

It's about balance and control . Whtherer sirpoc is a genius or just got lucky with the balance, who knows. I suspect it's the former though as he seems to have basically solved hobby training, or pretty close to what is optimal for himself and likely most of us, in two sports.

You can dive into the science and try and make your judgement, just beware that most studies are done to prove something rather then discover what’s best.

One way to look at things that tends to be very reliable is looking at best practices of the most successful runners.

The vast majority of the top world class distance runners over the past 50 years have run 13 times a week. Twice a day every day except their long run day. While brand new runners just entering the sport tend to run just 3 or 4 days per week.

So you have a scale, beginners on one side and best in the world on the other side. 3 times a week to 13 times a week. Slowest distance runners to fastest distance runners.

Keep this in mind when groups like FIRST try and convince you that you’ll run faster by running less. They are like a fad diet group, playing off what you want hear, trying to tell you that you can lose weight while still eating a dozen donuts a day if you just take their secret pill.

One of the reasons I think my above comment is the case, is the simple principle that the body adapts best to that which it does most frequently. In general, the more often we run, the better the body adapts to it. You just have to be careful and add runs smartly and gradually to allow the body time to adapt.

After 2+ decades of coaching, I can tell you the most injury prone runners I see are those who only run 4 days a week but insist on doing quality stress workouts and longer long runs. They are twice as likely to get injured then are runners who do that same quality workout and long runs but do 6-7 days of runs.

This has not been my experience.

Consider older runners. What do they eventually discover? That they can't run every day like they used to.

As we're seeing with resistance training studies, they're a nightmare to control for. There's also clearly a grey area between 'recovering' and actually recovering, which is hard to quantify.

Likely what you are seeing is a misinterpretation - older runners would be better off continuing to run as many days per week as they did when they were younger, just modifying what and how much they ran on those day. They take a day off rather than running less on their run days or lessening the frequency of stress workouts like they should.

The body does not recover in 24 hours or even 48 in the case of a workout, so in reality most (hard working) runners are probably running on legs <100% all week. I don't know that anyone has ever quantified the interval for a rest day, maybe its a 7 day week or 10th day? But it seems logical to recover physically and mentally.

Yes, but as ive always said, does your body know that we have organized everything into 7 day weeks and 24 hours in a day? "Most frequently" could mean every 12 hours, 24 hours 48 hours...I think we pick every day as most convenient, but maybe that's not optimal. I see the most injuries on the jump from 15-20 (middle school) to summer HS into XC 9th grade 25-35 miles (girls>>>>boys).

yeah you are never 100% in training til you do something like tapering. The question is if taking a 36-48 hour break instead of a 12-24 hour one occasionally promotes more recovery? I am not sure we can quantify all the recovery stuff to a level to measure that.

Your right. I am 71 and my body tells me often I need rest days. I didn't very often when I was young. This is particularly true after a hard workout like a hard long run or a high intensity interval session. The body takes longer to recover.

It seems logical to recover physically, but does taking a rest day actually aid in physical recovery? I don’t know science, but it’s my understanding that recovery is a continuous process that mostly occurs while sleeping but also while not running in general, so how would taking a day off increase recovery if the amount of weekly time spent not running and time spent sleeping remains consistent? There’s also (I think) the consideration that the release of growth hormone doesn’t occurring without exercise, which might make taking a rest day slightly worse for recovery.

sorry but it's bs to suggest that people who run 7 days spread their work out more, or those who take a day off respond by packing in more into less space on purpose. you're working backwards from a mileage obsession which would itself be debatable value. it's thus multiple layers of keeping up with the joneses silliness.

a basic flaw in the analysis here is people who test whether their practice regime works on monday (the day back after the break) instead of saturday (meet day), so to speak. the goal of practice is not running every day or hitting a mileage number, for their own sake. it's improving your place and time on meet day. i am in the church of iverson on this one. "are you talking practice??" i'll take feeling a little sluggish on monday after my rest, when nothing counts, for feeling better than you end of the week with the money on the table.

my guess is your grinder feels good a few weeks and makes early strides, then starts breaking down physically and mentally when the money is actually put on the table. the measured and restful approach gets you lively legs at the peak. it is focused on the self. the no rest approach, while posturing as a training approach for the self, is really insecure, outward focused, and fixated on outworking the joneses.

as your colleague said, running breaks down muscles, jostles tendons, beats up bone. you don't rest, eventually something breaks. or you get sick of it mentally. and then hopefully your idea of a race is you are lively and can go to the lead at some point, and not just that the race is more mileage you grind out in 10th place.

do you feel lively when you tie your shoes and step out the door? or are you grumbling i am so sore let's get this over?

And on the full rest day is someone still going out for a 40 minute walk with their family? That's still doing something.

to explain what i see as the difference, my youth select team won 2 state titles. we played hard structured team defense. but we only practiced 3 hours a week. but we trained hard for those 3 hours. and did little actual windsprints or long runs -- it was mostly just work rate within the practice. we would slowly start the season, often tie our first game, but then go undefeated in league and make state. we would peak later in the season. and we could outwork teams in games on natural gift.

vs. my college soccer team had endless practices going like 2-1/2 hours, beat the crap out of the players, tons of running. the coach would talk about how we'd outwork everyone with all the conditioning. we'd jump fast from the gate labor day. by late september 1/3 of the team would be hurt, quit, or carrying a knock. everyone was tired. the strong start would usually fade into a meh conference standing.

i think a few elite runners might benefit from all the work. i think most people are just breaking down your runner(s) obsessed with outworking someone else. to me you outwork someone else on the quality of the workouts. are you about intense quality or just grinding hardworking slop? my personal experience beating myself up day after day does not result in lively raceday legs. it's more of a psychological obsession. i can't believe you have to actually tell people, don't run before the meet, don't run yourself in the ground, take a day off once in a while. it's a footrace and you don't get bonus points for how many days in a row you trained or how sore you are for race day.