If you're looking to enter 2026 feeling like the best version of yourself, TikTok's "The Great Lock-In" — also known as the winter arc least season — may be the exact trend you've been looking for. "It's all programming your mind to go hard for a sprint of time. A sprint. It's not meant to be forever," explains creator Tatiana Forbes in a TikTok with over 800,000 views. "But it's meant to be a time you put forward an immense effort in some area of your life. It could be fitness, it could be your finances, it could be your career, it could be a business. It could be all the things."