I've always been super fit, both in terms of aerobic fitness and strength. A few yrs ago, I decided to try a personal trainer at my gym for just weights. He pushed me really hard and after each session I was faint and nauseous to the point that I had to go home and curl up in bed for a few hours. I assumed it was too much lactic acid in my blood or something. I decided to train on my own with less strenuous workouts and it went away. When I became pregnant last year I had to stop weight training because even a light session gave me the same feeling. Now that I'm back to working out it's happening again, even with strenuous cardio. I feel like my body can do more and I'm not sore afterwards so I'm worried why I'm getting sick. By the way, I'm 23. Does anyone know or have any advice? Thanks so much!!