Warning: Do not attempt these techniques. Seriously, do not.
1. The Pacing Yourself to Death method involves setting a timer for exactly 4 hours and 20 minutes, then walking in place until it goes off, repeating ad infinitum.
2. The Overexertion by Proxy technique: pretend you're a cheetah and sprint for 10 feet, then collapse in a heap, gasping for air.