Side-Lying Pillow Wedge

Wedge between the knees. The standard fix for lumbar or SI discomfort.

Both bodies supported laterally. The most sustainable family and the one to use when the goal is duration rather than intensity — cost is dominated by top-leg abduction and lateral core.

Difficulty 1 of 5

Muscle groups loaded

Adductors
Core
Hip flexors

Limiting capacity

Mobility limits this posture. Hip, adductor and thoracic range. Determines which positions are available and comfortable.

Train it · Open Hips Test your limiter

Intensity

What it costs, by role

Modelled intensity by role for Side-Lying Pillow Wedge
Role	METs	Band	Active-minute credit
Active role	4.1	Moderate	1×
Receiving role	3.7	Moderate	1×

Light is under 3.0 METs, moderate 3.0–5.9, vigorous 6.0 and above (CDC). A session averaging at or above the vigorous line has its minutes credited at 2× in the Active Minutes ledger.

Energy

Modelled kilocalories

Modelled energy cost for Side-Lying Pillow Wedge at 10, 20, 30 and 45 minutes for both reference bodies
Role · reference body	10 min	20 min	30 min	45 min
Active role · Male 82 kg	59	118	177	265
Active role · Female 68 kg	49	98	146	220
Receiving role · Male 82 kg	53	106	159	239
Receiving role · Female 68 kg	44	88	132	198

Estimates, not measurements

Every energy figure here is a modelled estimate, not a measurement. No study has measured cost position by position — the measured quantity is the session average (6.0 METs for men, 5.6 for women, Frappier 2013). These values distribute around that anchor by mechanical demand.

kcal = METs × 3.5 × bodyweight(kg) ÷ 200 × minutes (ACSM)

Values scale linearly with your own mass. If a position causes pain rather than effort, stop and see a clinician.

Mobility gate

Side-lying top-leg abduction to 45° with stacked hips.

Clear the gate before adding load or duration here. If range is the thing standing in the way, Open Hips is the block that builds it.

Prescribed preparation

01
Side plank
Stacked hips, long line from ear to ankle. 3 x 30s/side.
02
Copenhagen plank
Side plank with the top leg on a bench, adductors loaded. 3 x 20s/side.
03
90/90 hip switch
Seated, rotate knees floor to floor under control. 3 x 8/side.
04
Pelvic floor hold
Contract, hold 8s, then a slow 6s release. 3 x 10.
05
Zone 2 base
30–45 min conversational pace, 3–4x/week. The foundation under everything.

Cross-reference

Workouts that build this position · 15

Each of these loads the qualities this posture asks for. Equipment, modelled calories and the muscle groups worked are on every workout page.