Hands together, triceps in full panic mode.
Keep your elbows hugging your sides. Letting them flare turns it back into a regular push-up.
Bringing the hands together under your chest forces the elbows to stay tucked, which shifts the pressing work squarely onto the triceps through a long range of elbow extension. The chest still assists, especially the inner portion as the hands squeeze in, but the narrow base means your arms carry the rep. It is one of the best bodyweight moves for arm size and a natural upgrade once standard push-ups get easy.
The narrow hand position bends the wrists at an awkward angle for some people. Try turning the diamond slightly, spreading the hands a few centimetres apart, or doing them on push-up handles to keep the wrists straighter.
For triceps, yes. The tucked elbows and narrow base put far more of the load on the arms, while a standard push-up shares more of it with the chest. Keep both in rotation, they do different jobs.
Elevate your hands on a bench or do them from the knees while keeping the diamond shape. Keep the elbows hugging your sides in the easier version so the strength carries over.
