A nature break occurs when riders make a quick halt along their ride to use the restroom, usually in a spot along the road bounded by bushes or trees.
The rules do not say anything about nature breaks but are very necessary on long stages without a restroom. Teams prepare in advance for this, and the support staff guard the leaders when nature breaks. The riders have to ride to quiet and secure locations off the roads and support vehicles. A swift nature break makes them more comfortable and enables them to continue to ride well in a hard race even though they might lose a couple of minutes.
