12 Scientific Reasons Why Your Muscles Feel Stiff in Cold Weather (and What to Do About It)

3. Increased Muscle Tone from Nervous System Signals

Your autonomic nervous system reacts to cold by nudging the body toward a more protective state. Part of that reaction is an increase in baseline muscle tone—muscles hold a slightly higher level of tension even at rest. That’s helpful because a bit of extra tension helps conserve heat, but it also makes movement feel stiffer and more effortful. Hormones and signaling molecules released in response to cold, such as adrenaline, can raise this tone across multiple muscle groups. When tone is elevated, everyday tasks like lifting a dish or turning to look over your shoulder may feel tighter than they do in warmer weather. Gentle, intentional movements—breathing deeply, slowly mobilizing joints, and doing light resistance work—help retrain the nervous system to allow more relaxed muscle length, which lowers that chilly baseline tension over time.

4. Shivering and Involuntary Contractions Raise Muscle Activity

Shivering is the body’s rapid way of producing heat through repeated, involuntary muscle contractions. That trembling is effective for generating warmth, but it also tires muscles and creates a sense of stiffness afterward. Even sub-shivering contractions—low-level tremors you might not notice—can increase muscle fatigue and tightness. Repeated involuntary contractions can leave muscles slightly inflamed or sore, which compounds the sensation of stiffness when you try to move more deliberately. Counteracting this effect means reducing the triggers for shivering: aim to keep core temperature steady with clothing, warm beverages, or short active warm-ups. After any episode of shivering, give muscles slow, controlled movement and extra time for gentle stretching so they settle back into a more relaxed state without strain.