When should exercise be terminated in MS?

When should exercise be terminated in MS?

• A. If core temperature decreases by more than 0.5°C
• B. If core temperature increases ≥0.5°C (Uhthoff phenomenon)
• C. If heart rate reaches 100 bpm
• D. If perceived exertion is above 7/10

Answer: (B)

In MS, heat sensitivity can temporarily worsen neurological symptoms, a response called the Uhthoff phenomenon. When core temperature rises during exercise, nerve conduction in demyelinated pathways slows further, which can dramatically magnify symptoms like weakness, vision changes, or coordination issues. Stopping exercise if core temperature increases by 0.5°C or more is a safety cue to prevent this symptom flare and protect the individual during activity. The other options don’t reflect this heat-related safety trigger: a drop in temperature isn’t a sign to stop, a heart rate of 100 bpm isn’t specifically tied to MS heat sensitivity, and a perceived exertion threshold isn’t the established safety criterion for terminating exercise in this context.

In MS, heat sensitivity can temporarily worsen neurological symptoms, a response called the Uhthoff phenomenon. When core temperature rises during exercise, nerve conduction in demyelinated pathways slows further, which can dramatically magnify symptoms like weakness, vision changes, or coordination issues. Stopping exercise if core temperature increases by 0.5°C or more is a safety cue to prevent this symptom flare and protect the individual during activity. The other options don’t reflect this heat-related safety trigger: a drop in temperature isn’t a sign to stop, a heart rate of 100 bpm isn’t specifically tied to MS heat sensitivity, and a perceived exertion threshold isn’t the established safety criterion for terminating exercise in this context.