Why do feel so bad after long easy runs?

Probably should have said, 35yo and male

just eat more carbs before the long run

EIther run them faster OR, if you insist on going that slow, run them with other people.

Either of those 2 options will feel significantly better than running that long and slow alone.

Your welcome.

Hypoglycemia causes headaches. Something is causing loss of blood sugar. Something that only a long run creates. There are myokines that are secreted proportional to the duration of your run. There could be something like that which affects your kidneys. Kidneys filter out glucose, and then actively reabsorbs it. If something is amiss, you end up pissing out your glucose, and you get headaches and malaise. So, my guess is that your kidneys aren't working right.

In my best years my long runs rarely lasted longer than 1:40-1:50 and usually covered 16-18 miles. I did a lot more miles than you're doing and was a bit faster, but I've never been convinced that you need really long runs to run a decent marathon. There have been guys who don't do them at all and have run good marathons. I had a friend who hated long runs, never went beyond 12 except for one 15 which almost got him to give up the sport, rarely went much over 40 mpw, yet managed 2:40 and some seconds.

You could just limit your long runs to 90-100 minutes and run marathons anyway. The Law of Diminishing Returns says you're getting most of the benefits of your two hour runs in those 90 minutes anyway. Gains beyond that are sort of marginal. If you want to be ambitious, after you've done the 90-100 go out later for another 30-45 minutes. Or do the 90-100 on one day and do another 90 or so at midweek. Or, as someone else suggested, run harder. If you're going to suffer you might as well do it right and sometimes running too slowly can be uncomfortable.

90 minutes is a nice long run.

(that range between)

2 hours is a looong run.

1. In that range between (>90 min.) is where I eat some gummy bears along the way, and drinking something becomes a necessity. 90 minutes is so nice because you can just run and not worry about water or candy.

2. You might be suffering from boredom. I would be bored if my long runs were just continuous easy pace running, so they're not. I incorporate a workout into my long runs, and you should too. Pick it up to MP or HMP for some intervals (2 miles, 3 miles, 1 mile... with jogging between).

3. When you get back home lay on the floor, put your feet up (like put your butt at the wall and your feet up on the wall) and stay there for 5 minutes. (You can tickle your phone or something to pass the time.) It's like magic for recovery. Sometimes I skip this step when I'm in a hurry, but then I regret it.

What kind of surface are you running on?

Is it your normal 60min loop run twice or are you extending further out (and possibly slapping concrete/harder surfaces in the process)?

Try finding somewhere that you can get it all in on trails/grass. Might require hopping in the car and/or repeating a loop many, many times. Try it out.

I have had extremely similar issues to what you are describing. After a longer run (defined more by time on feet than distance) of over 90 minutes, I would feel extremely fatigued and lethargic after for most of the day. And it would mess up other activities I wanted to do in the day. However, if I would never have such feelings when I did a normal workout that usually ends up being 60-70 min of time on feet including warmup and cooldown.

I've recently started to work more on bringing some sort of fuel on even just 90 minute runs. It felt a bit silly but by having some carbs / sugars at ~45 min I was able to finish the rest of my day without suffering quite the same symptoms I was feeling before. I've chalked it up to my body being easily depleted of glycogen / poor ability to use fat as fuel, or something along these lines. Like you, I've ran for many years and my body has never "adapted" as some people might say it should. I never feel fatigued during the run, just afterwards.

You may have tried this already, but I would try being very methodological in fueling on longer runs -- try fueling more often, maybe at 45 min and again at 90 min. 30-60g of carbs each time. You'll have to play with the parameters a bit. I suspect dehydration is not really the issue here; as if you've had water stops, hydrate well before and after with water and/or a sports drink, it's hard to say you're dehydrated. I would be more inclined to believe your body is getting too depleted and so you feel terrible afterwards for that reason.

Guessing here, won’t claim special knowledge.

Under the premise that you are running out of glycogen, 3 things come to mind.

1) Go even slower. It can feel bad at first too if you haven’t practiced. (If ppl say will destroy form, see Canova’s example of 800m runner doing 3hrs @6min/km counter example)

2) Try running fasted, Not the whole 2hrs at first, but building up to. Goal to shift to more muscle storage, not depend on liver as much, use more fat in the mix.

3) Build up to even longer runs. Then, 2hrs will be easier. The top end of my range always makes me feel like you describe, I just don’t hit too often. Currently about 2.5 hours (fasted, with no fueling).

A fourth thing:

4 ) Scrap it all, enjoy what’s fun for you!

lurker wrote:

1) Go even slower. It can feel bad at first too if you haven’t practiced. (If ppl say will destroy form, see Canova’s example of 800m runner doing 3hrs @6min/km counter example)

Interesting. Do you have a link for this?

lurker wrote:

Guessing here, won’t claim special knowledge.

Under the premise that you are running out of glycogen, 3 things come to mind.

1) Go even slower. It can feel bad at first too if you haven’t practiced. (If ppl say will destroy form, see Canova’s example of 800m runner doing 3hrs @6min/km counter example)

2) Try running fasted, Not the whole 2hrs at first, but building up to. Goal to shift to more muscle storage, not depend on liver as much, use more fat in the mix.

3) Build up to even longer runs. Then, 2hrs will be easier. The top end of my range always makes me feel like you describe, I just don’t hit too often. Currently about 2.5 hours (fasted, with no fueling).

A fourth thing:

4 ) Scrap it all, enjoy what’s fun for you!

This

In addition I would have taken sports drink under activity instead of plain water. You might look much water during exercise and need electrolyte replacement.

Headaches might be cause by too sun exposure on the eyes. Wear a cap, also helps if you're getting bald. Cyclists who ride for hours at a time wear sunglasses.

jiggymeister wrote:

lurker wrote:

1) Go even slower. It can feel bad at first too if you haven’t practiced. (If ppl say will destroy form, see Canova’s example of 800m runner doing 3hrs @6min/km counter example)

Interesting. Do you have a link for this?

Too many links! :-) Had to hunt a little, found it:

I'm also guessing it's something with feeling (before, after or during). Maybe try some simple carbs directly after the run (not an hour after, but within minutes)? My go-to is chocolate milk (carbs and some protein). I've also noticed that I recover much better when I add some protein to my diet (using shakes to get the required amount in).

I know the feeling but mostly have it when I dig deep in a long run or race. I'm a dad of a 3yo, and it seems to be much worse when we're staying inside reading a book or playing. Going outside to the playground or for a walk in the forest is never a problem for me.

I always used to get headaches later in the day after a long run, until I started wearing sunglasses.

Thanks guys, some great replies here.

Had not considered the sunglasses factor, I'm in the UK so it's not like we get much sun; but I guess the extended time outdoors could be a factor regardless.

The biggest take-home I'm getting is that I may need to be more methodical with gels, so I'm going to try that approach, with maybe a gel at 30, 60, 90 mins (or 45/90) and see how I feel.

I don't think there is an awful lot I can do differently with pre/post run food/hydration. To the poster who said try and eat immediately; I try to do that already but may not have mentioned it - I have something small straight away, and then a meal within the hour.

Does anyone have any thoughts on whether it could be my own personal physiology that is at 'fault'? I feel my marathon is weak compared to my HM, and I always find marathon pace very hard in training. Plus obviously I've had bad experiences with long runs in a general way as above. Are some people just more suited to HM/10k rather than the Marathon?

I have friends who have a 2x HM + 5 minutes conversion for their marathon times; and it just blows my mind. I cannot fathom how they can do that. Horses for courses?

At the elite level, I remember Tadese seemed to be the example a few years ago. WR half, but a poor marathon PB (for an elite, obviously).

You could be a fast-twitch runner with a lot of fast-twitch muscle fibers and lots of natural speed. The guy that crushed everyone else at his ability level during the last 100-400m of a 5k/10k etc.

These tend to struggle with long, extended efforts especially at faster paces. FT fibers burn WAY more glycogen than ST fibers, so you would either need to add fuel during the run (and plenty before/after) or you just run at an even easier effort, with people who are much slower than you in a 5k race. I actually recommend the 2nd unless you train for marathons.

You want to avoid putting your body in a state where it's completely glycogen depleted. You've been there many times, apparently, and you know how it feels like. You can forget doing any quality training/session the next 2-4 days, that's how long it takes to get you back up again and restore your energy stores.

Hope that helps!

In addition to normal post run nutrition, my secret weapon is tonic water

Idk what it is about tonic, but removes any post run headaches etc

Also don’t forget caffeine, if you are a heavy coffee drinker