In most cases, the fabrics are no better than shaved skin at reducing surface resistance. Traditional-cut suits are best for breaststrokers. Any covering below the knee will reduce the effectiveness of the kick in both strokes. An upper torso covering tends to restrict the range of arm movement through decreased mobility of the back muscles. Women should pay particular attention to the cut along the back of such suits.
Women have to wear the top, with fewer men electing to do so.
Suits with ridges of stitching increase resistance. They should be avoided. In heavy, unshaved training, they could assist some swimmers to improve in performance. Once a taper is experienced, and a swimmer is shaved, they would serve no other advantage other than to increase a swimmer's flotation. One should not believe the advertising claims for these suits.