Why does sustained exercise sometimes make me very unwell for hours or even days?

August 5, 2012 5:42 AM

Why does sustained exercise sometimes make me very unwell for hours or even days? I lift heavy weights at the gym three times a week with no problems, I get enough sleep, I eat very healthily (but perhaps my intake is low on carbs like bread, pasta or rice). But every now and then, when I do a sustained cardio type exercise for about an hour or a little more (playing a sport, taking occasional breaks for water, etc), I start to feel fatigued before everyone else does, then I feel extremely sick to the point of having to sit down, not wanting to move. In extreme cases, I've been unwell for more than two entire days after.

I thought it might have been lack of pre-exercise nutrition, but today I had a great hearty meal with plenty of protein, a little bit of carbs and some vegetables about an hour an a half before, and yet it still happened.

Is it likely to be dehydration? I was pausing to drink water, and the exercise itself wasn't very strenuous at all, but it was sustained for more than an hour. I had a Gatorade afterwards, and I felt better, but I don't know if those two have any causality; it may have just been the passing of time.

I looked at these previous threads:

Running
Runner's Low
Grumpy

but none seemed to be exactly what I'm experiencing. Any suggestions? Thank you.

posted by surenoproblem to Health & Fitness (20 answers total)

I wonder if it's a salt thing? Maybe you need more of it, because you lose a lot when you sweat. Gatorade may be a better choice than water if you're working hard, just because it's got salt. You could probably add some salt to your water bottle, but I'm not sure what ratio you'd want.
posted by backwards guitar at 5:59 AM on August 5, 2012

Possibly because your cardiovascular system is unused to the stress you've placed on it (which is different than the stress induced by weightlifting).
posted by the man of twists and turns at 6:12 AM on August 5, 2012 [3 favorites]

You mention drinking water during these activities, but what about before? Not just immediately before, but in the hours leading up to your workout. If you're only drinking immediately before or during your workout, it won't hydrate you quickly enough.

Also, are you doing these activities outside? Being out in the summer sun totally zonks me after a while, even if I'm wearing copious amounts of sunscreen and just walking around. If you can, do things indoors or in the early evening, when it's still light but the sun's no longer directly overhead.
posted by Metroid Baby at 6:13 AM on August 5, 2012

What is "a little bit of carbs?" Because this really sounds like that's the issue.
posted by JPD at 6:16 AM on August 5, 2012 [1 favorite]

I thought it might have been lack of pre-exercise nutrition, but today I had a great hearty meal with plenty of protein, a little bit of carbs and some vegetables about an hour an a half before, and yet it still happened.


I used to do bikram yoga (the hot yoga - 90 minutes in a 105 degree room w/ 40% humidity) and we were told not to eat anything 2 hours before class. I usually followed that pretty much exactly, but one day I decided to have a banana about an hour before class...and totally regretted it. I was fatigued and had to lay down several times, had a stomach ache, etc.

Maybe try to have this meal at least 2 hours before working out.

We were also told to drink at least a few liters of water during the day before class. I realize you're not doing bikram yoga but it could be the same sort of situation.
posted by fromageball at 6:24 AM on August 5, 2012

You need to go see a doctor.

Forget trying to tweak your own health. This is unusual. The early fatigue, feeling extremely sick, and potentially being ill for days afterwards means that you need to consult with a physician and perhaps a cardiologist before continuing with this exercise regime.
posted by Mercaptan at 6:27 AM on August 5, 2012 [20 favorites]

I agree with Mercaptan that this is the kind of thing you want to see a doctor about. It could be some sort of cardiac arrythmia, or something else, and you really want to get cleared of those things before you continue exercising.
posted by pie ninja at 6:40 AM on August 5, 2012

Yep, see a doctor and get blood tests done and depending on that maybe even get referred to a specialist. Stop doing sustained cardio exercise until then.

No need to anticipate serious or worrisome things, it may just be something silly and easy to fix like low levels of a particular mineral maybe iron or something like that. But it still doesn't sound normal, and you would still risk jeopardising your health if you just try to guess why this happens and experiment around with changing meals or times or whatever, instead of getting checked by a medical professional. That's the only way you're going to find out what's going on, no one else can be as helpful.
posted by bitteschoen at 6:45 AM on August 5, 2012

Doctor doctor doctor. You need to see one. Hopefully you have already had baseline labs done in the past for comparison to now, but either way, go to the doctor and they can figure out what labs to order and what changes to recommend.
posted by bilabial at 7:00 AM on August 5, 2012

You don't say how old you are and what your typical days look like or how often you actually do cardio type exercise. If you are mainly sitting all day and not moving around much, your overall fitness might just be low. I agree with the man of twists and turns. If you feel like your lifestyle is active and you should comfortably be able to run up a few flights of stairs or run after the bus but can't it is time to see a doctor and have a cardiac stress test.
I disagree with Mercaptan, that this is unusual. Playing a team sport for an hour is tough to impossible for people with low fitness levels who rarely move.
Can you clarify what your symptoms are? Shortness of breath, high heart rate, feeling dizzy, feeling sick to the stomach? Can take a couple hours to normalize.
What are your symptoms the following day? If it is the same symptoms, not normal. If it is just overall fatigue and sore muscles, pretty normal after a tough work out.
posted by travelwithcats at 7:02 AM on August 5, 2012

The wanting to sit down/not wanting to move thing plus the low carbs thing sounds to me like you might be experiencing some level of glycogen depletion/'hitting the wall'. You may be thinking that that's something only experienced by marathoners/long distance cyclists, but if you are limiting your carbs, it's possible you could be depleting your glycogen (carbohydrate) stores after only an hour. I don't disagree with the doctor suggestions, but if it were me, before seeing a doctor I would at least try to rule out glycogen depletion as a cause of your problems.

I would try out having some carbs (at least 200 calories worth) a couple hours before you do any extended cardio exercise, and supplement with some sports drinks (gatorade/powerade-- NOT the low-cal versions) instead of water during your water breaks. After you finish, have another 200-300 calories of nutrition, mostly carbs (a 4:1 carbohydrate: protein ratio would be ideal).

You shouldn't need quite this level of carbohydrates during every cardio workout, but I would want to try to take in a LOT of carbs, to 100% rule out glycogen depletion as a cause of your problems. If you still have trouble, see a doctor for sure. If the carbs take care of it, you can work on finding the right level for you.
posted by matcha action at 8:05 AM on August 5, 2012 [1 favorite]

Not to be alarmist, but I have a friend who had these same symptoms once and when he finally got checked it turned out he'd had a long-running hepatitis C infection and was down to like 20% of his liver still functioning.

Doctor up.
posted by overhauser at 8:07 AM on August 5, 2012 [1 favorite]

Other people probably aren't as dumb as me but to mention a potential explanation: for a while I was using these beverage concentrates (1, 2, there's a Target generic brand too) without realizing that the "Energy Drink" versions had substantial quantities of caffeine. So I would work out and get dehydrated, then guzzle several glasses of it, and subsequently have to lie down because of heart palpitations and faintness.

As far as glucose levels, FYI, you can go into any pharmacy and buy a blood glucose meter for $20 or less. It's always best to see a doctor, of course, but if that's impractical for any reason to test this particular hypothesis you don't have to wait until you can get into a doctor's office.
posted by XMLicious at 8:34 AM on August 5, 2012

Definitely worth seeing a doctor. I was experiencing similar symptoms and it turned out that when I breathed in deeply, a ligament was cutting off the blood supply to my stomach (abdomen area?). They finally saw it on a CT scan and booked me in for surgery to loosen the ligament. No problems since.
posted by Jacqulyn at 9:09 AM on August 5, 2012

How is your conditioning? Being able to sustain long amounts of cardio is very different than weight lifting. If you are only doing this "every now and then," as you say, it seems to me that the simplest explanation could be that you are simply not used to that length of cardio and need to work on your endurance.
posted by Nightman at 9:11 AM on August 5, 2012

I would want to be tested for diabetes if I were you. If your energy levels are running low despite what you think is appropriate nutrition and hydration, and you are otherwise fit, this would be a simple thing to test and rule out.
posted by MuffinMan at 10:07 AM on August 5, 2012

All I can tell you is that I have experienced something substantially similar, but I was quite sick and trying to work out too early in my recovery.
posted by Nothing at 12:49 PM on August 5, 2012

Doctor ASAP! A cardio work-up and some glucose testing to see how your body is processing sugars seem like good places to start, given your symptoms. (IANAD IANYD)
posted by quince at 12:57 PM on August 5, 2012

Not everyone responds to exercise in the same hunky-dory way. Some people feel sick when they do a level of aerobic exercise beyond some particular threshold, due to some quirk or malfunction of metabolism, neurology, immunology or something else hard to pinpoint. This is not well understood, but it's real.

Definitely see a doctor, and be prepared to be persistent. You may have to see several of them, or dozens, before you get a hint of an answer. In the meantime, listen to your body. If something makes you feel sick, that thing is probably not good for you right now. Even if it's fun and it's clearly good for everyone else around you, trust your own experience. I think I made myself quite a bit sicker for a while by pushing against symptoms like that before being diagnosed with autoimmune diseases.
posted by Corvid at 1:33 PM on August 5, 2012

How is your blood pressure? Mine is pretty high, an I would often have a pretty bad spike in reaction to sustained exercise, and spend a few hours, or maybe the next day with some major fatigue, a headache and some nausea, it might be worth it to check your blood pressure before and after exercise.
posted by St. Sorryass at 11:37 PM on August 5, 2012