
Also works: Glutes · Hamstrings
Lying face down, you lift arms, chest and legs off the floor at once and hold the arch for a couple of seconds. Despite being filed under stretching, this is an isometric contraction of the spinal erectors and glutes — the only back-extension work most people can do with no equipment and no bench.
Set up first, then execute. Every cue below is something you can check on your next set.
Breathing & tempo — Exhale as you lift, breathe shallowly through the hold, inhale as you lower. Two seconds up, two-second hold, two seconds down — never hold your breath through a long isometric.
Where to start, and what to change when it stops being hard.
Bodyweight, and for most people that is the ceiling. Ten controlled reps with a genuine two-second hold at the top is a reasonable standard; a continuous 30-second hold means the erectors are doing their job. Progress by lengthening the hold or lifting only one arm and the opposite leg at a time before you ever consider adding a weight plate.
The errors that show up most often, and the cue that fixes each one.
Fix your eyes on a spot on the mat just in front of your hands and keep them there for the whole set. Your neck should travel exactly as far as your ribcage does, no further.
Cut the range in half and squeeze the glutes hard before anything leaves the floor. A pinch means you are hinging at one lumbar segment instead of extending along the whole spine.
Two seconds up, two-second hold, two seconds down. This is an isometric — a fast rep skips the only part that trains anything.
Clench your glutes before the legs move and keep them clenched throughout. If you cannot feel them, do a set of glute bridges first and come straight back to this.
The spinal erectors mostly work isometrically in real lifting: they resist a deadlift folding you forward rather than pulling you upright. Lifting both ends of your body off the floor makes them shorten against the weight of your own arms and legs, which is a small load but applied through a long lever, so a two-second hold is harder than it looks.
The glutes and hamstrings finish the leg half of the movement. Lifting the legs without squeezing the glutes just cranks the lower back, and that is the difference between a rep that trains something and a rep that leaves you stiff. Keep the arch modest — hands and feet 10-15 cm off the floor is enough.
As accessory work at the end of a lower-body or pulling session, two to three times a week, or as daily maintenance if you have no gym access. Do not put it before deadlifts or squats — a pre-fatigued set of erectors is the last thing you want under a heavy bar.
No kit, too hard, or too easy — here's where to go instead.
A strength exercise, whatever the category label says. Your spinal erectors are shortening against load, not lengthening. If you want to stretch the lower back, hug your knees to your chest — this is the opposite movement.
Hands and feet about 10-15 cm off the floor. Any higher and you stop extending the whole spine and start hinging at one or two lumbar segments, which is where the pinch comes from. Range is not the variable to progress here; hold time is.
For a beginner or anyone training at home, near enough. A 45-degree bench lets you load the movement with a plate and work through a much longer range, so it will keep progressing after this stops. Use this until you have a bench, then use both.
Mild muscular soreness across both sides is normal for the first couple of weeks, in the same way any new exercise makes you sore. Sharp pain, one-sided pain, or anything travelling down a leg is not — stop and cut the range.