Push
Russian dips are an advanced parallel-bar dip where, at the bottom, the forearms rest on the bars and you must press from that forearm support back to full lockout. That adds extreme triceps range and huge demand on the long head.
From a normal dip position, lower to 90°. Continue descending (leaning forward) until the forearms rest on the bars. From there, press back to the starting lockout. That is a full Russian dip range.
The triceps (especially the long head) must produce force at max length—extraordinarily hard and highly effective for strength and muscle.
Only for athletes who can do 15+ clean parallel-bar dips. Start with partial range (just the last degrees of extension from the forearms).