Can an athlete carry a drink, or take one from someone else?

• Carrying: "An athlete may, at any time, carry water or refreshment by hand or attached to their body provided it was carried from the start or collected or received at an official station."
• The offence: receiving or collecting refreshment or water "from a place other than the official stations", or taking "the refreshment of another athlete".
• The exception: refreshment given for medical reasons by race officials, or under their direction.
• First offence: a warning from the referee, normally by showing a yellow card.
• Second offence: disqualification, normally by showing a red card. The athlete "shall then immediately leave the course".
• Sharing: "An athlete may receive from or pass to another athlete refreshment, water or sponges provided it was carried from the start or collected or received at an official station."
• Sharing too much: "any continuous support from an athlete to one or more others in such a way may be regarded as unfair assistance", with the same warnings and disqualifications.
• Warning first: outside the stadium the referee should give a warning before disqualifying wherever practicable.

If drinks could come from anywhere, an athlete with helpers along the route would have an advantage over one without, and nobody could check what was in the bottle. Limiting the source to the start and the official stations keeps it equal. Letting athletes share a bottle between themselves allows an ordinary act of sportsmanship, while the limit on continuous support stops one athlete being used as another's carrier.