Don't save ab exercises for the end of your workout. Here's why

Don't save your ab exercises for the end of your workout, says Luke Worthington, a human movement specialist and elite personal trainer. In fact, for the best workout overall, you should activate your abs and core muscles as part of your warmup — or what Worthington calls "movement prep" — to prime them for the work ahead (via Insider).

Activating your core as well as your glutes improves your positioning throughout your workout, Worthington told Insider. But be careful: Activating your abs is like switching on these muscles, not training them toward fatigue. Doing 20 minutes of ab work and then lifting weights or focusing on another muscle group actually can cause injury.

There's another reason to not save your ab exercises for the end of your workout: the possibility that you'll skip them altogether, says certified professional group fitness instructor Cathe Friedrich. Some people understandably don't want to exhaust their abs or core doing deadlifts, squats, or other compound strength exercises. But if you're tired after that other work, you won't give your core the focus it deserves (via Cathe).

Activate your core with just a rep or two

Activating your core doesn't involve doing lots of reps or sets, Worthington says. It's more like a gentle wakeup so they're ready to assist you. "Activating those muscle groups should be part of everybody's movement prep," he explains. "It's a super important muscle group because it allows you to get into the best position to then do the workout that you want to do." 

Worthington recommends nudging your abs into action with a simple exercise called dead bugs: Lie on the floor with your arms reaching straight up toward the ceiling. Form your legs into a tabletop by bending them 90 degrees at the hips and knees (as if you're sitting in a chair). Keep your shins parallel to the ground and the ceiling.

Then lower your left arm so you reach above your head while straightening and lowering your right leg. Keep your straightened leg off the floor, and don't arch your spine. Return both limbs to your starting tabletop/arms overhead position. Then repeat the movement on the other side. 

You just need one or two of these stretches to say, "Hello, abs" and engage those muscles.

A plank or forearm plank works your entire core

You don't have to get on the floor to activate your abs, however. Worthington says you can activate your core during the middle of your workday using a yoga, cardio, or mobility routine. Then once you return to your desk, your core is engaged to help you sit correctly.

As for your regular workout, just activate your abs for a few moments at the start, then work in your core exercises as you normally would.

The best exercises to strengthen your core are those that engage the entire midsection, according to SELF. These include the plank: Place your palms flat on the floor with your shoulders above your wrists. Extend your legs behind you with your feet hip-width apart. Extend your arms as if in a pushup, then tuck your tailbone to engage your core, quads, and butt. Hold for 15 to 30 seconds. 

A forearm plank modifies this: Instead of extending your arms, rest on your forearms with your elbows beneath your shoulders and hands facing forward so that your arms are parallel. Extend your legs and tuck your tailbone as in a regular plank pose, then hold.