Excerpted from https://www.sleepadvisor.org/stretching-before-bed
For starters, developing an evening stretching routine helps your body to enter a relaxed state more quickly, and stay in a deeper sleep for longer. With fewer points of pain along your back, neck, and shoulders, you’re less likely to toss and turn. This is great for your sleep — and your partner’s sleep, too.
Stretching provides a great alternative nighttime activity to scrolling through social media or reading emails on a screen. When done correctly, studies have shown that practices like yoga and stretching can be incredibly relaxing and meditative. Focusing on your body and the present actions can be a great way to separate yourself from the day’s stresses and signal to your subconscious to stop worrying.