Ronny Terry is a Swindon-based personal trainer. He has previously worked as Performance Analyst with Swindon Town FC and on obesity initiatives with the NHS. Tweet your questions to @SWITCHFITUK or visit www.switchfituk.co.uk

Q I keep getting cramp in my lower leg – what it is and what can I do about it?

A Leg cramps are a common condition usually affecting the calf muscles, although any part of the limb can be affected including the feet and thighs.

Often occurring at night, muscles suddenly contract becoming tight and painful, and discomfort may be felt for several hours afterwards.

Cramps are common in people over 60 and also during pregnancy.

Idiopathic cramps are those which occur for no apparent reason but are thought to arise when a muscle, already in a shortened position, is stimulated to contract further.

Secondary leg cramps are caused by underlying conditions and other causes. Cramps experienced during or after exercise are thought to be the result of water and mineral imbalances alongside the repetitive use of a muscle.

During pregnancy, lower circulating levels of calcium and magnesium, and changes in weight and hormone levels are said to be contributory factors.

And muscular spasms are linked to some medicines used to treat high cholesterol, osteoporosis and high blood pressure.

For those who live a sedentary lifestyle, getting up and active more regularly should result in a reduced onset of cramping. Gentle stretching in the evening and light massage to the area may also help. Staying hydrated with water or electrolyte sports drinks during exercise is a good idea, especially in hot and humid conditions where fluids are lost as sweat.

The quickest method for relief is to gently stretch. For cramp in the calf, sit on the floor and wrap a towel around the sole of the foot on the affected side and take an end in each hand. Straighten the leg and pull your foot and toes towards you.

If you think your cramps may be caused by medication or an underlying condition, call your GP.