Kapala Bhati

Sit in easy pose
Sit down + extend legs in front (dandasana)
Flex knee to chest
Rotate hips externally
Supination of both feet
External rotation of right knee (put right knee on left thigh)
Back straight (erectus spinae muscles eccentric contraction) + hands on knees
 
Inhale
Abdomen relaxes, diaphragm contracts (external intercoastal muscles contracts)
 
Exhale
Contract transverse abdominis mucles (concentric contraction)
Contract intercoastal internal muscles
Contract pelvic floor muscles (Mula Dhara)