I have been suffering from cramps in my legs at night - I have woken up at least 5 times per night this week and the only cure is to jump out of bed. It must be that my body is getting used to the cycling again.
Nocturnal leg cramps are involuntary muscle contractions that occur in the calves, soles of the feet, or other muscles in the body during the night or (less commonly) while resting. The duration of nocturnal leg cramps is highly variable with cramps sometimes only lasting a few seconds and other times several minutes. Soreness in the muscles may remain for some time after the cramp ends. These cramps are more common in older people but may happen to anyone. They can happen quite frequently in teenagers and in some people while they are exercising at night. Nocturnal leg cramps can be very painful, especially if the person is dehydrated.
The precise cause of these cramps is unclear. Potential contributing factors are believed to include dehydration, low levels of certain minerals (magnesium, potassium, calcium, and sodium), and the reduced blood flow through the muscles attendant in prolonged sitting or lying down. Less common causes include more serious conditions or the use of drugs.
Nocturnal leg cramps may be relieved by stretching the affected leg straight out and pointing the toes upward. People report that quickly standing up and walking a few steps may also shorten the duration of a cramp.
Nocturnal leg cramps (almost exclusively calf cramps) are considered to be 'normal' during the late stages of pregnancy. They can however vary in intensity from mild to incredibly painful.