Is this the same as Thread the Needle?

No. Thread the Needle is a kneeling stretch for the upper back, while this is a strength exercise that moves between a forearm plank and a side plank. Some programs also call a side plank where the top arm threads under the torso a side plank rotation, which is a different drill from the alternating version on this page.

Is it better than a regular side plank?

It trains something different rather than something better. A Side Plank builds endurance with a continuous hold on one side, while the rotation trains you to stay rigid through repeated changes of position on both sides. Many programs use both.

Should I do it on my forearms or my hands?

The forearm version shown here is the usual starting point because the whole forearm shares the load and the wrists stay out of it. Doing it from a high plank on the hands means balancing on one straight arm through each turn, which asks more of the shoulder and wrist, so move to it once the forearm version is steady.

How many reps should I do?

Most programs use 2 to 3 sets of 8 to 12 rotations per side. End the set when the hips start to drop or the turn gets sloppy, since quality matters more than the count.

Why do I feel it in my shoulder?

Some shoulder work is expected because one arm holds your body up. Pressure at the front of the shoulder usually means the elbow has drifted out from under the shoulder or you are sinking into the joint, so reset the elbow and push the floor away before each turn.

Plank to Side Plank

What Is the Plank to Side Plank?

Plank to Side Plank is a compound exercise that primarily targets the core and also engages the hips and shoulders. It is an intermediate-level movement that links two holds: from a forearm plank, you roll onto one forearm into a side plank, reach the top arm to the ceiling, then return to the plank and turn to the other side.

The value of the exercise is in the transition. A plank asks the trunk to resist sagging, and a side plank asks it to resist bending sideways, so turning between them makes the abs, obliques and hip muscles keep the body rigid while the base of support shrinks from two forearms and two feet to one forearm and the edges of the feet. In an EMG study of healthy adults comparing nine body-weight exercises, the static side bridge was the one the authors identified as strong enough to build the external oblique and the gluteus medius, and every rep here passes through that position.

It is not the drill many programs call a side plank rotation, where you stay in the side plank and thread the top arm under the torso, which keeps the load on one side for the whole set and adds more twisting through the trunk. Plank to Side Plank alternates sides and turns the whole body as one unit, so it trains control of the turn rather than spinal rotation.

It fits in a core block, a warm-up before upper-body or rotational work, or a body-weight circuit, and it is usually done for reps rather than time. If the hips drop as you turn, build up with a solid Plank and Side Plank first, or do the rotation with the knees down. Once it feels easy, pause at the top of each turn, or do the same pattern from a high plank on the hands to add a straight-arm balance on every turn.

Muscles Worked

MuscleActivation

External Oblique: Primary
Deltoid: High
Gluteus Medius: High
Rectus Abdominis: High
Erector Spinae: Medium
Serratus Anterior: Medium
Gluteus Maximus: Low
Latissimus Dorsi: Low
Lower Trapezius: Low
Tensor Fasciae Latae: Low

Instructions

Start in a forearm plank with your elbows under your shoulders, forearms on the floor and hands in loose fists.
Straighten your legs and rise onto your toes with your feet about hip-width apart.
Brace your abs and squeeze your glutes so your body forms a straight line from head to heels.
Shift your weight onto your right forearm and rotate your whole body to the left as one unit, pivoting on your feet.
Let your feet land staggered on their edges, with the top foot in front of the bottom one, and keep your right elbow directly under your shoulder.
As you turn, sweep your left arm up until it points straight at the ceiling, in line with your supporting arm.
Pause with your hips lifted, chest open and neck in line with your spine.
Lower your left arm and rotate back to the forearm plank, placing your left forearm under your left shoulder.
Repeat to the other side, rotating onto your left forearm and reaching your right arm to the ceiling.
Breathe out as you rotate up and breathe in as you return, and alternate sides until you finish an equal number of reps on each side.

Common Mistakes

Letting the hips sag
Dropping the hips during or after the turn takes tension off the obliques and shifts the load into the lower back.
Elbow out of position
Letting the supporting elbow drift forward or away from under the shoulder puts pressure on the front of the shoulder.
Sinking into the shoulder
Collapsing toward the supporting shoulder instead of pushing the floor away through the forearm loses shoulder blade control and strains the joint.
Turning in pieces
Twisting the chest first and dragging the hips and feet around afterward turns a whole-body rotation into a twist through the lower back.
Rushing the rotation
Swinging from side to side with momentum skips the controlled transition that makes the exercise work.
Piking the hips
Pushing the hips high in the front plank to make the turn easier breaks the straight line from head to heels.

Injuries

Plank to Side Plank is a low risk exercise when performed with proper technique. There is no external load, the forearm support spares the wrists, and the side plank position trains the trunk without the heavy compression on the lower back that comes with curls or back extensions.

The supporting shoulder takes the most stress. If the elbow drifts forward or out from under the shoulder, or the body sinks into the shoulder joint, you will feel pressure at the front of the shoulder. Keep the elbow stacked under the shoulder and push the floor away through the forearm on every turn. The lower back is the other strain point: when the hips sag during the turn, the lumbar spine takes load the abs should be holding, so slow down and keep the hips in line before adding reps.

To make it easier, practice the Plank and Side Plank as separate holds, or rotate with the knees on the floor. To make it harder, hold the top position for a 2-count, or perform the rotation from a high plank on the hands, which shifts more of the balance to the shoulder and wrist. Stop if you feel sharp or pinching pain in the shoulder, pain that travels from the lower back into the leg, or numbness or tingling in the arm.

Overview

Primary Focus: Core
Equipment: Body weight
Modality: Strength
Difficulty: Intermediate

Alternative Exercises

Frequently Asked Questions

Q: Is this the same as Thread the Needle?: No. Thread the Needle is a kneeling stretch for the upper back, while this is a strength exercise that moves between a forearm plank and a side plank. Some programs also call a side plank where the top arm threads under the torso a side plank rotation, which is a different drill from the alternating version on this page.
Q: Is it better than a regular side plank?: It trains something different rather than something better. A Side Plank builds endurance with a continuous hold on one side, while the rotation trains you to stay rigid through repeated changes of position on both sides. Many programs use both.
Q: Should I do it on my forearms or my hands?: The forearm version shown here is the usual starting point because the whole forearm shares the load and the wrists stay out of it. Doing it from a high plank on the hands means balancing on one straight arm through each turn, which asks more of the shoulder and wrist, so move to it once the forearm version is steady.
Q: How many reps should I do?: Most programs use 2 to 3 sets of 8 to 12 rotations per side. End the set when the hips start to drop or the turn gets sloppy, since quality matters more than the count.
Q: Why do I feel it in my shoulder?: Some shoulder work is expected because one arm holds your body up. Pressure at the front of the shoulder usually means the elbow has drifted out from under the shoulder or you are sinking into the joint, so reset the elbow and push the floor away before each turn.