"If you've been working out intensely before you got pregnant, you should continue to do it," Anna Kaiser tells PEOPLE

Should you be working out while in the first trimester of pregnancy?

Anna Kaiser – who trains Kelly Ripa, Shakira and more – says you definitely should be. And as a fitness pro who is four-months pregnant herself, she knows what’s she’s talking about!

“Don’t let pregnancy become an excuse to just skip it,” the creator of AKT in Motion tells PEOPLE. “The first reaction is to sleep and relax, but I feel so much better after an intense workout. If you’ve been working out intensely before you got pregnant, you should continue to do it.”

Kaiser says working out regularly can help stave off some of the first trimester hardships.

“You’ll feel like a million bucks,” she says. “The nausea’s going to go away, the exhaustion is going to go away, you’ll feel so much more focused, your body’s going to feel better.”

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Not sure what you should and should not do? Kaiser breaks down the do’s and don’ts of working out during the first trimester:

DON’T do repetitive movements of any one body part. “There are definitely specific types of workouts that are better than others,” says Kaiser. “Doing any sort of high-impact movement for an extended period of time is just not good for your body at that point.”

DO find a workout buddy. “Notoriously, the first trimester is the hardest trimester because you’re extremely tired, you’re nauseous,” she says. “Go with a friend to keep you accountable. Just get yourself there, even if you stop after 30 minutes.”

DON’T do a workout that you’ve never done before. “Don’t do anything new,” says Kaiser. “Your body needs to know what to expect, and you need to know how hard you can push yourself.” It also helps to choose workouts you know you enjoy, because you’re more likely to actually do it. “Do something that’s fun, because you’re not feeling so good!”

DO interval training. “Interval training has been such a saving grace, whether it’s circuit interval training or dance-based interval training, because you get that great endorphin rush, but it’s in short periods of time, it’s non-repetitive moments so you don’t put too much stress on any one joint or ligament, and you’re engaging all your muscles and getting dynamic flexibility, which helps with backaches,” says Kaiser.

DON’T hold stretches for too long. “When you have a lot of relaxin and you’re holding stretches or yoga poses for a long period time, you can end up sitting too deeply and it can do more damage than good.”

DO work out first thing in the morning. “I find that if I don’t get up and do it first thing in the morning, it gets harder to do,” says Kaiser. Plus, it sets you up to feel better for the rest of the day. “You’re holding onto fluid, you feel bloated, you may feel constipated, and exercise helps with every single one of those.”

DO eat before and after your workout. “Before getting pregnant, I would work out after not eating for an hour or two, but you can’t do that when you’re pregnant,” says Kaiser. “You have to eat because otherwise your body is pulling from its reserves. It should be giving those reserves to your baby, not to the workout.”

DON’T do any quick up and down movements. “Avoid any move that’s going to push your neck against gravity,” says Kaiser. “The up and down movement also isn’t great with nausea.” (Which means pregnancy is a great reason to avoid burpees!)

DO strength train. “I have found that using slightly heavier weights and doing less reps – so slow and controlled while lifting more weight – feels really good,” says Kaiser. “You can be specific about what muscles you engage and how. Adding extra weight also helps keep your heart rate up.” Kaiser says to focus on building up back muscles with back flies and back extensions, and do pec exercises and stretches to help with soreness. The focus should be on large muscles throughout this time.

DON’T do any exercises that require you to lie on your stomach. However, you can continue to strengthen the core muscles during the first trimester. “As you continue through pregnancy, you want to focus less on your rectus abdominus muscles because they’re going to be stretching out and it may cause tearing,” says Kaiser. “You can get them strong during the first trimester, but then focus less on them in the second and third. Focus more on transverse abdominus and inner obliques.”

DO meet with a trainer who understands pregnancy. “You really want to meet with someone who understands what’s going on with your body, and avoids putting your body in a compromising position.”