Stop Believing These RDL vs SLDL Instagram Reels

They’re Wrong, Oversimplified, and Bad Coaching

If you’ve seen one, you’ve seen ten.

Side-by-side videos.

Bright muscle overlays.

Arrows on the hips.

And the confident claim:

“RDL = glutes

SLDL = hamstrings”

Here’s the truth, plainly:

These reels are rubbish.

They look smart. They sound confident. And they completely misunderstand how your body works.

1. They’re showing the same exercise twice

Both versions are the same basic movement:

• You bend at the hips

• Your knees stay mostly straight

• You lift the weight back up

That’s called a hip hinge.

Changing how much you stick your bum out or bend your knees a tiny bit does not magically turn it into a different exercise.

It just changes how it looks on camera.

2. You cannot “turn off” your hamstrings like that

Your hamstrings cross:

• Your hip

• Your knee

As long as:

• Your knees are fairly straight

• You bend at the hips

Your hamstrings are working.

Every time. No exceptions.

So when an Instagram coach says:

“This version takes hamstrings out”

They’re either ignorant or lying for clicks.

3. Pelvic tilt is not muscle targeting

A favourite trick is exaggerated posture:

• Big arch in the lower back

• Bum pushed back

• “Glute focus” arrows everywhere

That doesn’t change what muscles are doing the work.

It just:

• Makes the lift look different

• Often puts more strain on your lower back

• Helps the video look “educational”

Good posture on Instagram ≠ good biomechanics.

4. Muscle diagrams don’t mean muscle control

Those red-and-green muscle pictures?

They’re marketing, not science.

They don’t show:

• How much force a muscle produces

• Which muscle is doing most of the work

• What’s actually being loaded

They’re there to make you feel like something precise is happening.

It isn’t.

5. This is why these coaches love these reels

Because they:

• Sound simple

• Give fake certainty

• Make people feel clever for “knowing the difference”

Real coaching is boring by comparison:

• It depends on the person

• It depends on the load

• It depends on tolerance, history, and goals

Instagram doesn’t like that.

6. The reality, in plain English

If your knees are mostly straight and you’re hinging at the hips:

• Your hamstrings are working

• Your glutes are working

• Your back is working

You are not isolating anything.

You are biasing slightly — and even that depends on the person.

7. Why this actually matters

This isn’t harmless content.

People:

• Avoid exercises thinking they’re “hamstring safe”

• Overload movements based on fake targeting

• Get injured following advice that sounds confident but isn’t true

And then they think they did something wrong.

They didn’t. The advice was bad.

Final message

If someone on Instagram tells you:

“Do this version to hit glutes, this version to hit hamstrings”

They’re not coaching you.

They’re feeding you content.

Good training isn’t about tricks, angles, or arrows.

It’s about mechanics, load, and progression.

If it sounds too neat to be true in fitness…

it almost always is.