Complex sentence: Whole Body Cryotherapy initially originated in Japan in 1978 but it was a group of polish scientists who took the idea and made Whole Body Cryotherapy the effective physical therapy it is today.
Split into simpler sentences: Whole Body Cryotherapy initially originated in Japan in 1978. However, it it was a group of Polish scientists who took the idea and made Whole Body Cryotherapy the effective physical therapy it is today.