Butterfly kip vs C-kip, which is safer/better?

A member asked how it is possible that his major lifts are improving even though we only go heavy once a week. His old gym lifted heavy every day. Now he goes heavy only once a week and lifts are going up. How is this possible?

Is "Rowing Murph" a good modification for people who cannot run?

Weight belts & knee sleeves...do they have utility?