The thought of being trapped under the ice on a frozen lake would give most people nightmares, but for Czech freediver Petr Kapoun it’s actually a hobby.
The questionably sane swimmer went for a lap underneath the ice using a yellow guide rope and completed the lap without dying, which is really the only measure of success in this sport. He also set the world record for shrinkage, besting one George Costanza.
Keep a paper bag close by in case this makes you have a panic attack.