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DrSugar Answers: Postworkout Weakness?

DrSugar is in the house and answering your questions.

Dear DrSugar,
Sometimes after a rigorous cardio workout (one hour, doing intervals for the first half hour and steady pace for the second half), I come home and start feeling queasy and weak, then need to lie down. Sometimes I feel this way for an hour or more postworkout, well after I've showered and eaten. There have been a few times when I've lost my stomach as well. But it usually goes away after an hour or so of resting/lying down. What's going on? I try to be well hydrated and have a little snack a bit before working out, but sometimes, it doesn't seem to help.
— Workout Weary Wendy

If you're curious to see how DrSugar answers this question, just


Feeling queasy or weak following or during rigorous exercise could be due to a variety of factors; however, lactic acidosis is the most likely cause of your symptoms. Lactic acid is produced by muscles during anaerobic metabolism. Lactic acidosis most commonly occurs after long, rigorous exercise like you’ve described. Common symptoms of lactic acidosis include nausea, weakness, fast heart rate, hyperventilation, and sometimes even anxiety. Lactic acidosis can be more of a problem when coupled with dehydration, prolonged exercise, starvation, alcohol use, and strenuous exercise when not in excellent physical condition.

Preventing lactic acidosis can be difficult if your goal is prolonged anaerobic exercise such as sprints or intervals. The first step is to maintain adequate hydration before, during, and after your workouts. Another way to avoid this problem is to separate your aerobic and anaerobic workouts on alternate days by jogging Mondays, Wednesdays, and Fridays and doing sprints, intervals, and/or weights Tuesdays and Thursdays.

The other possible cause of your symptoms is low blood sugar, which can also cause weakness or queasiness during or after exercise. To prevent low blood sugar you can avoid prolonged exercise on an empty stomach, before breakfast, or before dinner if you didn’t eat an adequate lunch. And, of course, always avoid starvation diets. They don’t work and they are dangerous. Sometimes these post-exercise symptoms can be related to an underlying metabolic problem such as diabetes or liver disease, therefore it is highly recommended that you see a physician if the problem persists.

If you have a question for DrSugar, send me a private message here and I will forward it to the good doctor.

DrSugar's posts are for informational purposes only and should not be considered medical advice, diagnosis, or treatment recommendations. Click here for more details.

Join The Conversation
ilanac13 ilanac13 8 years
i've had the issue with the low blood sugar thing before and that's kind of what makes me most shaky and tired after a work out. i think that it's a bit disconcerting when you're finished with a GREAT work out and then you can't hardly function afterwards.
Martini-Rossi Martini-Rossi 8 years
This happens to me once in a while, actually I experienced this on Monday. Im pretty sure it was due to the fact that I only a had pizza for lunch - which was hours after my workout.
pixelhaze pixelhaze 8 years
when I first started working out I would also feel sick after. Not as bad as described here, but it was a feeling that if I were to eat anything I would throw up. It kind of went away when I got more used to working out, and then it was the opposite - the minute I finished my workouts I would be famished. That's probably not the case here, but I thought I'd share :)
Rexo Rexo 8 years
I'm glad someone asked this question cause I often feel sick after a good workout. I'll try focusing on becoming better hydrated and eating properly before and after the workout. Thanks for the good tips and informative post.
bananapancake84 bananapancake84 8 years
I'll definitely have to try eating something before I work out. I always eat after (I usually go to the gym after work and then have dinner when I get home) but next time I'll try having a snack beforehand too. I always drink tons of water. I'll also try breaking my cardio in half and doing strength in between. Thanks for the tips!
urban-chic-101 urban-chic-101 8 years
Question... Do you guys eat something before working out? I would suggest eating something before you workout. I have a high-protein slim-fast shake or something like that before and then something light after wards to even out the calories. I would also suggest breaking up your cardio, maybe do some in the beginning and then do some weights or w/e and then more cardio. I hope this helps! Lactic Acid is a real biatch, but it is something you can work to overcome. :D
bananapancake84 bananapancake84 8 years
This happens to me almost every time I do cardio for more than 30 minutes. It's very frustrating and has been discouraging me from exercising. I always feel sick after a workout, not energized like everyone says I should.
Lovely_1 Lovely_1 8 years
This happens to my bf too...he just ahs to lay for hours after the gym :( But he has diabetes and I know that's what causes that in him! It sucks, but it's part of life!
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