Headaches later in the day after harder rides

I am trying to figure out optimal nutrition to avoid what is becoming fairly common for me. After intense rides, if even 60 minutes, often later in the day (i typically train early in the morning), I’ll get a headache and feel moderate fatigue. When training for 60-90 minute duration i’ll drink SIS Go electrolyte/carb mix during the ride and SIS rego after. on the 90 minute rides i’ll typically have a gel with 25-50 grams of carbs as well. Sometimes i’ll also have an SIS electrolyte tablet after a ride too. This is all with me trying to figure out if I have an electrolyte problem (I am a salty sweater). I haven’t been able to figure out what the problem is. I wouldn’t say that I have the best diet, so it could be food related too. Any thoughts?

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How much are you sweating? I get headaches when I don’t drink enough. Usually only the next day, but could easily be the same day too.

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I’ve struggled with that exact issue over the years. Often I’ll feel fine after the ride but later in the evening and/or the next morning I’ll wake up with a headache. I don’t drink alcohol at this time, but it very much feels like a hangover type headache. The length of the ride don’t seem to be a factor but the intesity is. Rides with hard threshold or above efforts trigger it.

I tend to take in a lot of calories on the bike, so that wasn’t the issue for me. However getting protein and carbs in right after the ride seems to be the key for me. Recovery drinks seem to work best. But it has to be almost right after. If I don’t, and say take a shower and clean up first and then have dinner an hour after the ride, I might still get the headache. It’s weird, but that’s ultimately what helped me.

You are already doing the SIS Rego, so maybe just make sure you do it right afterwards rather than waiting. Taking in some additional electrolytes, such as drinking fluids with the SIS electrolyte tabs, in the hours after the ride certainly wouldn’t hurt either.
For me the solution has

I definitely had headaches after hard rides in the heat and humidity in the past, and that resolved when I started adding electrolytes to my water. Can you believe I’d do rides on plain water? And I brought something like one Clif bar for a 50-60 mile ride.

What gives me pause is that you are asking when it’s winter in the Northern hemisphere, and you do already take electrolytes during your rides. You did note that you’re a salty sweater. Maybe you are well above the norm. On darker clothes, do you get a lot of salt staining after long rides? I’m counting long indoor rides and outdoor summer rides. I get some, not an immense amount, but I think I’m average to above average. Maybe you’re in another league in that regard.

Also, can you say how long you’ve had this issue?

You could be way, way off on electrolytes depending on how much salt you lose, and how much you’re sweating. How many mg of sodium are you taking in during and directly after a hard workout?

I personally lose ~1200 mg per liter of sweat based on the sweat testing I’ve done, and people can supposedly be over 2000 mg/L. In certain workouts I can also sweat over a L/hr, so if you do the math, electrolyte needs can be pretty high.

One gel isn’t a lot for a hard workout either, but that could contribute to the fatigue. I personally am taking in 100g / hour on hard workouts and am still burning way, way more than that.

(For anyone asking, it’s cold here outside, but on the trainer I can still sweat a ton in the winter)

Sounds like dehydration. I get something similar on hard days if I don’t take in enough electrolytes or if I’m just drinking plain water. I tend to crave salty foods for hours as well. It does feel similar to a hangover, which I remember reading was actually because there’s a small drop in CSF and your brain sags and things stretch inside the skull, but that could be a bro science thing and not actually true.

Here’s a small study showing dehydration after exercise and a small change in CSF (read by MRI). Could explain headaches.

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Agreed with dehydration and electrolyte loss.

Do a sweat rate test (easy with a scale) and find someone local to do a sweat salt analysis.

I did both and it helped tremendously with both headaches and cramps. The test showed I was losing 1500mg/L sodium in sweat, and I sweat anywhere from 1 to 1.5L per hour.

Do you take a large dose of caffeine before/during your morning workout?

Sounds like me, when I was chronically dehydrated. I’d drink lots of water during the ride, but it wasn’t enough. When I started drinking water all day and adding enough electrolytes during and after the ride, I’ve finally been able to avoid those dehydration headaches after rides.

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I had the same problem for many years. For me, I needed liquid AND electrolytes AND carbs. Carbs was the last puzzle piece for me. Now I make sure to have some carbs, even on short rides, and make sure I was doing at least 70g+ per hour on longer rides. I add in some caffeine occasionally as well, if I’m going more than 2 hours.

This works for me. I suspect everyone’s formula is unique to them.

I had similar problems and noticed even with what I thought was adequate electrolyte consumption I would still sometimes get headaches after hard rides or rides in hot weather. I started looking at what was in the electrolyte mixes and figured out that I wouldn’t get headaches if whatever I was drinking had a decent amount of magnesium specifically (it took me years to get to the bottom of this one). These days I tend to stick with electrolyte mixes with higher magnesium content and I actually take supplemental magnesium as it seems to help me sleep better as well and it’s really helped on the headache front for me.

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Just for me, but I was at a conference and brought my bike and trainer, and rode a wicked race on Zwift, I sweat like crazy, way more than normal, and even though I drank a liter and a half of water, I felt like crap afterwards. Headache and bonky feeling (snarfed 2 Skratch bars). Someone said what did you drink? ‘Water!’ How much? ‘Liter and a half’ You need to drink a lot more water! Like NOW!

I got back to the room and downed a whole liter of water, and expected to have to pee a lot over the night. AND: Didn’t. I was severely dehydrated, and that ‘extra’ liter likely still wasn’t enough, but it helped. My headache went away, AND I felt dramatically less bonky/knackered.

DRINK MORE WATER! And even though you might have to pee more after a ride, that apparently does not mean you drank enough water during the ride/race. I drink more water after a ride now. I also do ‘just water’, but supplement with bananas and/or a bar or portion of a gel, for really long efforts.

Looking back on my biking career, I have suffered near severe dehydration several times. Yikes…

Thanks for starting this thread! I’ve had this problem a lot - especially in the summer and when indoor training.

After reading the responses, I think it might be low sodium causing it for me. I’m working to increase my sodium intake, and that seems to help…

Here is some data from a recent 90 min trainer ride.

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Super interesting! What do you think of the hDrop? I hadn’t heard of it before this, but it looks potentially very useful, if it’s accurate…

I just started using h drop hoping it would help provide some insight. No idea of it’s accurate or not but reasons seem consistent so far on a few rides.

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1000mg an hour or I get headaches. In the height of summer I’ll up it to 1250-1500mg

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Going up to 750 mg has changed my riding (was doing a single Hammer Fizz tablet @ 250mg Na). I drink a lot less water on the bike since upping the sodium, too.

Good stuff already mentioned with hydration and electrolytes.

If these are VO2-type sessions or something else where you’re entering an oxygen debt, that will do it too. Might be as simple as that.

:100: %. I thought I was taking in plenty of water and sodium and was having all types of issues (headaches, lethargy, etc) post workouts and hot races. After several frustrating years I finally had a sweat test done. Apparently I loose 1100mg of sodium an hour and 1L+ of water (depending on the conditions).

Since I’ve upped my hourly intake to sodium 1100mg, carbs 100g and water to 1L (even on the trainer with 4 fans), all my post workout issues have disappeared. Figuring this out has allowed me this past year to really push my training and surprise myself.