Walking up a single flight of stairs may leave you as winded as you would have felt climbing five flights prepregnancy. You might find yourself huffing and puffing halfway into an exercise routine that you used to be able to breeze through. That's OK. During the 3rd trimester, it's normal to become easily fatigued by activities that you could easily do a couple of months ago. You're carrying around more weight than before, which can tire you out. And if you're uncomfortable in bed or waking up constantly to go to the bathroom, you may not be getting enough high-quality sleep.
The best way to respond to fatigue is by slowing down. If you ignore it and push yourself to exhaustion, it's not good for you or your baby. Put your feet up and relax. Go to bed early, sleep late, ask your partner to take on more of the household chores. Listen to your body and give it what it needs.
Being thirsty, hungry, or hot can amplify feelings of fatigue. You may feel less worn-out if you stay hydrated, eat frequent mini-meals and snacks, and keep cool air flowing while you exercise. Choose snacks that offer a mix of protein and carbohydrates, such as cheese and crackers. Carbohydrates give immediate energy; the protein hangs on and fuels you after carb energy runs out.