Cyclists should not wear underwear under tight-fitting cycling shorts, but can wear cycling underwear under loose-fitting shorts. The underwear should fit snugly, have adequate padding, be breathable, and have tight hems and waistband. Synthetic fabrics are recommended for moisture-wicking, but should be washed frequently to avoid odor buildup.
Many cyclists don’t wear underwear at all, as cycling shorts are snug and padded, and underwear worn under the shorts will only bunch up and cause discomfort. People who aren’t comfortable wearing tight-fitting cycling shorts might consider buying cycling underwear, which can be worn comfortably under loose-fitting shorts. Cycling underwear should be adequately padded, comfortable, and lightweight; Breathable underwear will make your bike trip even more enjoyable, as the drier your skin stays, the less likely it is to chafe or otherwise get irritated.
Choose cycling underwear that fits snugly. This underwear should still feel more snug than regular underwear, although it shouldn’t feel too tight. The tighter the underwear, the less chance there is of excessive movement which can lead to chafing. The waistband should be tight enough to keep the cycling underwear in place at all times, and the legs should have tight hems that prevent excessive movement. Fewer seams on underwear means less chance of chafing, although some multi-panel undergarments will have more seams; this is done to promote a tighter fit. Make sure the seams aren’t overly loose or rough to avoid irritation.
The most important part of any cycling underwear is the padding. The padding should be thick enough to provide support while sitting on the bicycle saddle, but not so thick and loose that it interferes with normal leg movement. If the filling is too thick at the time of purchase, don’t worry too much, as the filling often compacts after several uses. Some pads are made to be antibacterial; these underwear options will be more expensive, but are well worth the investment as the padding prevents the buildup of bacteria that can be potentially harmful.
Cycling underwear must be exceptionally breathable. Synthetic fabrics are often used because they are specifically designed to wick moisture away from the skin, keeping you dry and comfortable. Moisture build-up on the skin can lead to chafing and hot spots, which will only get worse over the course of a bike ride. Synthetics will keep you dry and comfortable, but remember that synthetics tend to capture a significant amount of body odor, which means your underwear may smell bad at the end of a run. Wash your underwear frequently and choose materials that stand up to frequent washing in the washing machine.