Feet in the straps, obliques on lockdown.
The unstable straps want to wobble you, keep hips high and stacked.
Stacking both feet in the cradles and holding a side plank means your obliques are not just supporting your bodyweight sideways, they are stabilising a base that actively wants to swing. Every second of the timed hold is spent keeping the hips high and stacked against wobble in directions a floor side plank never produces, one side at a time so imbalances have nowhere to hide. It earns its place as the honest test of lateral core strength, and a straight upgrade once floor side planks stop being challenging.
Meaningfully. Suspended feet can drift forward, back and down, so your obliques stabilise three directions at once instead of one. Most people lose ten to twenty seconds off their floor hold time.
Only as long as your hips stay high and stacked. A twenty second hold with a perfect line beats a minute of slow sagging, build duration from there on each side.
Lateral core imbalances are near universal and this exposes them because each side works alone. Start every session on the weaker side and match the stronger side to it.
