A celebrity fitness trainer reveals 3 dynamic ab, arm, and glute moves you can do at home for a summer beach bod

Let's start with your stomach. "If you want your abs to appear flatter and to be stronger you have to strengthen the deep core stabilizers," Kaiser told Business Insider.

Kaiser said one of the biggest mistakes people make when working on the core is assuming that doing lots of crunches will help them develop a killer six pack.

Instead, here's the approach she suggests for sculpting "awesome flat abs":

Start seated on the floor, with your knees bent. Take hold of the area behind your knees with your hands and pull in your abs while tilting your pelvis forward. This will create a c-shaped curve in your spine. Next, raise your arms and press them towards the back of the room in little pulses.

All the while, keep those abs in and the spine curved.

Try a set of 10 or 20 of these to start.

Next, Kaiser suggests a twist on the standard push-up that will tone your entire upper body and give you tighter, trimmer arms.

To start, come into a half plank (knees on the ground) or full plank (knees off the ground, as pictured).

From there, lower down to a push-up position. Bring your chest all the way down to the floor, and then back up to where your arms are at a 45-degree angle.

"You're getting every type of muscle contraction in your upper body," Kaiser said.

There are three types of muscle contractions that happen when you're doing strengthening exercises: concentric (shortening), eccentric (lengthening), and isometric (stabilizing).

Repeat this move 10 times. Then there's another step: Maintain your bent arms and all that contraction in your upper body, and simply lift and lower your knees to the ground in six slow, deliberate taps.

Then push back up into your plank or half plank and do the whole routine again. This time, complete six push-ups and four knee taps, and then do the circuit one last time with just four push-ups and two knee taps.

Here, you're "working every muscle in your arms, as well as your back," Kaiser said.

Stretch out for a rest in child's pose afterwards. You've just worked your arms, your back, and your core at the same time.

For her third and final toning exercise, Kaiser shares a butt-shaping move. If you've got a set of dumbbells, get them ready now.

A little more weight — but not too much — will give you some extra oomph here, since you're going to be working some of the largest muscle groups in the body.

Stand with your legs slightly wider than hips-width distance apart, and your toes pointing out at a 45-degree angle. Hold a couple of moderately heavy weights at your chest, elbows bent at your sides.

Kaiser suggests eight-pound weights here, but try whatever feels a little heavy for you.

Now, lower down into a deep squat, dipping your butt even lower than your knees.

Keeping your heels on the floor and your toes pointed out, press into your feet and stand up, squeezing your glutes the whole way up.

Make sure you're really driving your heels into the floor and pressing your glutes together, so the work is in your butt, not your quads.

Finally, once you're standing, press your arms together overhead.

That final move "gives your heart rate a nice boost," Kaiser said.

It's important to remember slimming down isn't all about working out. Kaiser said diet is an important component of any shape-up plan. "The worst thing that can happen is you just go four or five hours without eating, and then you're really hungry and you reach for stuff that's not great for you," she said.

Kaiser plans time for meal prepping twice per week so that she has plenty of belly-filling proteins with her when she's on the go.

"I will make a ton of meat and fish and poultry on Sunday, and then again on Wednesday," she said. "It's not always easy to get protein if you don't prepare in advance."