Mastering the butterfly stroke takes time, patience and consistancy. But what makes the butterfly stroke so hard to learn? Well the most diffucult part is to get the timing between the arm movement and the butterfly kick right and at the same time to build up speed for a forward moving flow. #swimmingskills #swimtraining #ironmanswim #swimminglove #speedousa #markusmarthaler #waterlover #swimmingtechnique #tri #swim #swimdrills #swimmingdrills #swimtip #swimvideo #triathlonswim | Markus Marthale