Even when I first started working out I didn’t get lightheaded and weak, maybe ask one of the trainers at the gym?

You should make a doctors appointment just to be on the safe side and have all of your levels checked, like iron and thyroid and the routine stuff.

I have low iron, I get pretty ridiculous symptoms because of it and one is that I feel more drained and very weak.

I go to the gym. I can tell you this if you haven’t used your muscles in a long time they will be weak. And if you have not done much weight training and more cardio like walking or biking your muscles waste away. So now you have to build that back up. I’ve always exercised without weight training and when I started the weights I could barely push 20lbs on the leg press 8 weeks later im at 90lbs. It takes time. My arms are still pretty weak. If you are doing 20lbs thats pretty good, I’m doing 30lbs.

Sometimes the nausea might be just your body’s way of trying to get rid of crap. I’ve seen this before on the biggest loser where one guy threw up almost every single workout.

If I were you I’d get a quick physical check up. If you believe in your heart it’s just good old tiredness and fatigue from pushing it hard, try increasing your protein intake, after the work out. Also make sure you get plenty of iron and potassium. As well as always be hydrated. Being dizzy is the bodies way of telling us to calm the fuck down and back off the activity. However, if it only lasts about 2 minutes after a work while you’re catching your breath I wouldn’t worry about it so much.

Low blood sugar? Are you eating enough to sustain the level of activity you’re undertaking? I know you ate but perhaps you need a few more carbs or something.

Absolutely see a medical doctor ASAP. Go to a Urgent Care Clinic and describe your symptoms. Ask for basic blood chemistry tests and blood cell counts to be run as well an an EKG.

Good health!

@Bellatrix raises a good point. If your diet makes your prone to even mild hypoglycemia, then a sustained vigourous workout can really lower your blood sugar. Peanut butter supplies mainly fat, and small amounts of protein and carbohydrate. An apple supplies water, fibre and fructose – a simple sugar that is metabolized quickly, especially when you are exercising. Consuming a lower glycemic food source that provides gradually burning carbohydrate would serve you much better. Of course consult your MD to rule out anything more serious. Once you are medically cleared, discuss your diet and exercise routine with someone trained in both exercise physiology and dietetics. Most well educated trainers are educated in these subjects.

Stop the workouts. Take a break. Then do a formal workout program with either a good trainer or a good book like Body For Life.

@gondwanalon Urgent care for post work-out light-headedness? Ha, a bit extreme, no? I’ll save my $100 copay on that one.

I feel completely fine now. I came home from the gym, did my ab workout, took a shower, and went about my day. That weak feeling lasted 20 minutes tops. It wasn’t that, “I need to sit down before I pass out” type of thing.

I’m fairly certain I’m fine physically – after googling this I’ve found plenty of people with similar issues. I think, although I’m eating good foods, I need to eat more throughout the day, as @Bellatrix suggested. I’ve been eating 1200 calories, but those are gross calories, not net. When I take my exercise into account, I’m at under 1000 calories. Not good.

I’m just really out of shape. I wouldn’t call what I’m doing vigorous workouts, and I just got done with a 3 day break after 4 days at the gym, so I definitely don’t need a break.

If increasing my food intake doesn’t make a difference, I’ll see a doctor.

How much is your health worth? Less then $100?

@gondwanalon Some things warrant a visit to the doctor and some don’t.

@livelaughlove21 Your last statement is true. I was only trying to be helpful.

FYI: I started to feel light-headed, weak with dry heaving while exercising in 2001. A visit with a medical doctor revealed that my heart was in atrial fibrillation (a life threatening condition that causes ischemic strokes, 70% of such patients will die from it). It only takes about 48 hours of constant a-fib for a clot to form in your heart’s left atrium. Many people don’t realize that they are in a-fib especially if they are sedentary. They are very likely to feel lightheaded, nauseous or crappy when the do hard physical work or workout or go up stairs quickly.

Good health!