If somebody told you their workout included dead bugs, bird dogs, clamshells and fire hydrants, you could be forgiven for wondering whether they were exercising or describing a very strange afternoon.
The names are funny.
The exercises themselves aren’t a joke.
Several of these simple movements are used in fitness and rehabilitation settings because they challenge muscles involved in core control, hip movement and stability. Better still, most require nothing more than enough floor space to stretch out comfortably.
But don’t mistake “simple” for “magical.”
A dead bug exercise won’t melt belly fat. A fire hydrant won’t transform your hips in seven days. And doing 100 glute bridges isn’t a substitute for an otherwise inactive lifestyle.
What these exercises can offer is much more useful: approachable ways to move and strengthen different parts of your body without turning exercise into an ordeal.
So grab a comfortable spot on the floor. We’re going to meet some of the strangest names in fitness—and find out why they’ve stuck around.
First Up: Why Would Anyone Exercise Like a Dead Bug?
Lie on your back.
Raise your arms toward the ceiling. Bring your hips and knees up so they’re bent at roughly 90 degrees.
You now understand the name.
From that position, the dead bug exercise typically involves slowly extending one leg and the opposite arm while trying to maintain control through your trunk. Then you return to the starting position and alternate sides.
It looks uncomplicated.
That’s deceptive.
Your arms and legs are moving while your trunk is being asked to remain controlled. Research examining common core exercises confirms that the dead bug engages abdominal musculature, and a small six-week study in previously untrained young adults found improvements in measures of core strength and endurance among participants assigned to dead bug training. Those findings are encouraging, but the study involved only 29 people, so they shouldn’t be inflated into claims that the exercise prevents injuries or cures back problems.
The real value of the dead bug core exercise
Think less about “working your abs” and more about controlling your middle while your limbs move around it.
That’s relevant to far more than workouts. Your trunk routinely has to manage movement while you walk, reach, carry things and change position.
When you’re learning the movement, don’t worry about getting your heel almost to the floor.
Move only as far as you can while maintaining comfortable control.
If your position falls apart, shorten the movement.
That’s not cheating.
That’s adjusting the exercise to your present ability.
Then There’s the Bird Dog—Which Is Almost the Dead Bug Turned Over
Now roll onto your hands and knees.
Extend one arm in front of you while extending the opposite leg behind you.
That’s the bird dog exercise.
The name comes from the resemblance to a hunting dog pointing toward its prey. But from an exercise standpoint, something more interesting is happening: you’ve reduced your points of contact with the floor while asking your trunk to resist unnecessary movement.
Harvard Health describes the bird dog as a core-stability exercise that also involves the glutes and other muscles. Research using ultrasound and electromyography has likewise documented activation of trunk musculature during bird-dog variations.
And here’s something worth remembering:
Higher isn’t necessarily better.
If lifting your leg higher makes your pelvis rotate dramatically, you’ve changed what you’re doing just to create a bigger-looking movement.
A smaller movement performed under control can make considerably more sense.
Try this little test
Perform the movement slowly enough that you could stop your arm and leg halfway through.
Can you hold that position without wobbling all over the place?
That’s a much more interesting challenge than racing through 20 repetitions.
The Fire Hydrant Exercise Has an Unfortunate but Accurate Name
Stay on your hands and knees.
Keep one knee bent and lift that leg outward to the side.
And suddenly the name fire hydrant exercise requires no further explanation.
The movement involves hip abduction—moving the thigh away from the body’s midline—and challenges muscles around the hip.
This is where fitness writing can become misleading, so let’s be careful.
You’ll sometimes see fire hydrants advertised online as exercises that will “reshape” a particular body part or somehow remove fat from one location.
That’s not what we’re promising here.
You’re performing a hip exercise.
That’s enough.
Keep your hands underneath or near your shoulders, maintain a comfortable trunk position, and raise the leg through a range you can control rather than twisting your entire body just to lift the knee higher.
You should feel like you’re moving your hip, not performing a wrestling match with the floor.
The Clamshell Exercise Might Be the Quietest One Here
Lie on your side with your knees bent and your legs stacked.
Keep your feet together and gently open the top knee before bringing it back down.
That’s the clamshell exercise.
No jumping.
No sweating required.
No dramatic movement.
Yet laboratory research has found substantial gluteus medius involvement during clamshell variations. In one small electromyography study of healthy men, the clamshell remained gluteus-medius dominant across several hip positions.
That doesn’t mean everyone needs clamshells, nor does muscle activation alone prove that an exercise produces a particular long-term outcome.
It tells us something simpler and more defensible:
The movement recruits muscles around the hip that many people are specifically trying to train.
One common temptation is to roll the pelvis backward so the knee can open farther.
Don’t chase distance.
Open the knee while keeping the movement controlled. When your pelvis wants to join the party, you’ve probably gone far enough.
Glute Bridges Don’t Have a Funny Name—But Don’t Skip Them
Now lie on your back again, bend your knees and place your feet on the floor.
Raise your hips from the floor, pause comfortably, and lower yourself under control.
That’s the basic glute bridge exercise.
Bridge exercises activate muscles involved in hip extension and trunk stabilization. Research comparing stabilization exercises has documented trunk-muscle activity during bridges, although the amount and pattern of activation changes with the particular bridge variation.
Here’s where restraint matters again.
You don’t need to drive your hips toward the ceiling.
If getting higher means dramatically arching your lower back, you’re no longer simply demonstrating better hip extension.
Think controlled lift, not “highest bridge wins.”
And don’t rush immediately to single-leg bridges, weights, bands and unstable surfaces because somebody online called the basic version “beginner.”
Beginner isn’t an insult.
It’s where you learn the movement.
Butt Kicks Are the Odd One Out—and That’s Useful
Stand up for this one.
The butt kicks exercise involves a light jogging motion while alternately bringing each heel toward the glute.
Unlike the slower floor exercises we’ve just covered, butt kicks are commonly used as part of a dynamic warm-up. Johns Hopkins includes them among movements used to increase heart rate and blood flow before sports activity.
You can start slowly.
You don’t need to hammer your heels against your backside or sprint in place like somebody just yelled “fire.”
The purpose determines the pace.
If you’re warming up, gradually increasing movement makes more sense than exhausting yourself before the actual activity begins.
And this highlights something important about our little collection of strangely named exercises:
They aren’t interchangeable.
Dead bugs and bird dogs emphasize trunk control. Clamshells and fire hydrants emphasize movements around the hip. Bridges involve hip extension and trunk musculature. Butt kicks are dynamic and commonly used in warm-ups.
That’s much more useful than pretending they’re six versions of the same exercise.
Could You Put Them Together? Yes—but Don’t Turn This Into Another Fitness Challenge
This is where articles often go wrong.
You’ve just learned six exercises, so somebody inevitably announces:
“DO ALL SIX EVERY MORNING FOR 30 DAYS!”
Why?
You don’t need another arbitrary challenge.
If you’re relatively new to exercise, you could simply learn a few of these movements and gradually decide which ones belong in your routine.
For example, a session might begin with an appropriate dynamic warm-up such as butt kicks, followed later by controlled strengthening or stability movements such as dead bugs, bird dogs, bridges or clamshells.
How many repetitions?
There isn’t one scientifically correct number for every reader. Your current fitness, technique, goals, health and the difficulty of the variation all matter.
Start conservatively enough that you can actually pay attention to what you’re doing.
Then progress gradually.
Save this article if you want to come back and learn one movement at a time. There’s no advantage to memorizing the whole thing today.
What About an Exercise Ball?
An exercise ball can add variety and instability to certain movements.
But here’s the part that might save you some money:
You don’t need one for the exercises we’ve just covered.
Research on core exercises performed on unstable surfaces shows that changing the surface can alter muscular demands. But “more unstable” does not automatically mean “better” for every goal or every person.
Learn the basic movement first.
Equipment can come later if it serves a purpose.
That’s a useful principle well beyond exercise balls.
The Biggest Benefits of Exercise Won’t Come From One Clever Movement
This may be the most important part of the article.
Dead bugs are useful.
Bird dogs are useful.
So are many exercises we haven’t discussed.
But no individual movement carries the established health benefits associated with being physically active overall.
Current U.S. physical-activity guidance recommends that adults work toward at least 150 minutes of moderate-intensity aerobic activity each week, or 75 minutes of vigorous activity or an equivalent combination, plus muscle-strengthening activity on at least two days per week. And importantly, some activity is better than none.
The documented benefits of exercise extend well beyond muscles.
Regular physical activity is associated with lower risks of heart disease, stroke and type 2 diabetes, better bone health, improved sleep and other physical and mental health benefits.
That gives these funny little exercises some perspective.
They’re tools.
They’re not the entire toolbox.
You Don’t Have to Become a “Fitness Person” Overnight
There’s a strange psychological hurdle that sometimes comes with exercise.
People imagine the gym.
Machines they don’t understand.
People lifting enormous weights.
Complicated programs.
Special clothing.
An exercise ball, a leg exercise machine, perhaps a recumbent exercise bike—and suddenly getting healthier feels like something that requires equipment, expertise and an entirely different lifestyle.
It doesn’t have to begin that way.
A patch of floor can be enough to learn a dead bug.
Your hands and knees are enough to try a bird dog.
A short walk is still physical activity.
And five minutes of movement doesn’t become worthless simply because somebody else exercised for an hour.
The CDC explicitly notes that adults who sit less and perform any amount of moderate- or vigorous-intensity physical activity can gain some health benefits.
That’s a much calmer place to begin.
One Last Thing Before You Try Them
Exercise shouldn’t be a test of how much discomfort you can tolerate.
Muscular effort and unfamiliarity can be part of learning a new movement. Sharp or significant pain is different.
If you have an injury, chronic health condition, disability, significant balance problem, recent surgery or another issue that could affect exercise safety, an appropriate healthcare or exercise professional can help determine which movements and modifications make sense for you. The CDC specifically recommends that people with chronic conditions or disabilities consult an appropriate professional about suitable types and amounts of activity when needed.
For everyone else, remember why we started here.
Dead bugs.
Bird dogs.
Fire hydrants.
Clamshells.
Glute bridges.
Butt kicks.
They have ridiculous names because somebody had to call them something.
What matters isn’t the name. It’s finding forms of movement that you can perform appropriately, build upon gradually and—most importantly—keep doing.
Your body doesn’t care whether the exercise sounds impressive.
It only knows that you moved.
Sources
Centers for Disease Control and Prevention (CDC)
Adult Activity: An Overview
Centers for Disease Control and Prevention (CDC)
Health Benefits of Physical Activity for Adults
Harvard Health Publishing
Bird Dog Exercise for Your Core: How to Do It Safely
Source
PubMed
Examining the Effects of Altering Hip Orientation During Common Hip Rehabilitation Exercises
PubMed
Trunk Muscle Activation During Stabilization Exercises
This article is for general educational information and isn’t individualized medical or exercise advice.