Stress doesn't just affect how you feel — it shows up directly in your sleep data.
What's happening in your body
When you're stressed, your body releases cortisol — a hormone that signals alertness. Cortisol is useful during the day, but elevated levels at night work against sleep. They make it harder to fall asleep, push your body toward lighter sleep stages, and can cause brief arousals you may not even remember. All of this shows up in your AlterMe data.
How stress affects your metrics
Wind Down — high stress before bed typically means a longer Wind Down time as your nervous system takes longer to settle
Awake periods — cortisol spikes during the night can register as brief awake periods, even if you don't remember waking up
Deep sleep — stress tends to reduce time spent in deep sleep, the most physically restorative stage
HRV — one of the clearest stress signals. A lower HRV reading often reflects that your body is still managing stress load, even during sleep
What you can do
Try our Yoga Nidra meditation course — designed specifically to improve deep sleep quality by guiding your nervous system into a state of deep rest
Use a sleep meditation before bed — even a single session can help reduce Wind Down time and support longer, more consistent sleep duration
Time your exercise appropriately — physical activity is one of the best tools for stress and sleep, but aim to finish intense training at least 2–3 hours before bed to give your heart rate time to settle
Keep your sleep environment cool — a room temperature between 65–68°F (18–20°C) is generally considered optimal for sleep quality
Wind down intentionally — limit alcohol close to bedtime, which compounds stress-related sleep disruption