Exercise associated muscle cramping or EAMC is defined as painful spasmodic and involuntary contraction of skeletal cramping that occurs during or immediately after exercise. The most common muscles affected are those in the calf, but in cyclists the adductors (inner thighs) quads (front of upper leg) and hamstring muscle (back of leg) may also be involved. – By Dr Mérchen Naudé

TREAD 23Training - Cramp-2The aetiology of cramps is still hotly debated among athletes and scientists. Some claim electrolyte and fluid imbalance as theculprits. Cramping due to heat (heat cramps) were first described among coal miners in 1923, but the subsequent belief that cramps are caused by severe dehydration and sodium chloride losses that may develop during hot conditions, has no scientific basis.

Cramps can occur at rest or during and even after exercise undertaken in any environmental conditions. The more modern hypothesis proposes that cramps probably result from alteration in spinal neural reflex activity activated by fatigue in susceptible individuals. That is quite a mouthful. But what does it boil down to for us mountain bikers? Continual muscle contraction with an increase in excitatory neural signals results in a cramp. Therefore, immediate inhibitory techniques such as stretching is an effective means of treatment, and something you can do out on the trail.

Passive stretching reduces muscle electromyographic activity within 10 to 20 seconds. Stretch the affected muscle for 20-30 seconds, after which the muscle can gradually return to normal length. Intermittent episodes of cramping pain in a calf muscle may be due to an inadequately rehabilitated calf muscle strain. There is no guaranteed prevention for cramps. Some evidence exists that regular muscle stretching and correction of muscle balance and posture may reduce EAMC. Adequate and specific conditioning for the activity is also proven to be important. If the race is a 70km marathon event, fitness and conditioning needs to be adequate for that length of race. Also, if you are riding Sabie, you need to be conditioned to ride those hills!

Mental preparation for competition, avoidance of provocative drugs and maintaining adequate carbohydrate reserves during riding may also reduce the risk for cramping. Some authors advocate strategies such as eccentric muscle strengthening and the treatment of myofascial trigger points (massage by a sports physiotherapist or massage therapist or regular use of a foam roller). Some doctors may still prescribe magnesium supplementation, as magnesium is an important transport mineral featuring in muscle function. Thus, adequate conditioning and carbohydrate intake, a regular stretching programme and magnesium supplementation may reduce your risk for cramping. And if you are cramping badly on day one of the Wines2Whales, stretching the affected muscle for 20-30 seconds may get you to the finish and thatlong awaited beer!

Dr Mérchen Naudé is a Sports Physician practising in Pretoria, and is an avid triathlete and mountain biker.

She can be reached on 012 753 1257 or merchensport@gmail.com


TREAD Magazine is sold throughout South Africa and can be found in: Spar, CNA, Exclusive Books, Discerning bike shops and on Zinio

Originally published in TREAD Issue 23, 2013 – All rights reserved



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