MUSCLE CRAMPS: NO LINK BETWEEN HYDRATION AND CRAMPS Roberto Merchán Baeza Virgilio Ramírez Romero Exercise Physiology and Exercise testing ERASMUS OLOMOUC 08/09

What is a muscle cramp? Involuntary contraction that happens suddenly to one or some of more muscles. CAN RESULT Intense pain Unable use of the muscle This is called “spam” A forceful and sustained spam becomes CRAMP (Charley horse) It can last few from a few seconds to a quarter or hour (sometimes even longer) CRAMPS are extremely common.

Which are the main symptoms of a cramp? 1.Sudden and sharp muscle pain (involuntary contraction). Quite often in LEGS. 2.A hard lump of muscle tissue that you can feel or is visible beneath your skin (visible or palpable hardening of the involved muscle).

Which are the causes of muscle cramps? In many cases the exact CAUSE of a muscle cramp is not identified. Vigorous activity Dehydration Holding position long time Muscle strain Overuse muscle (vigorous use) Muscle fatigue During the activity or many hours later. It’s the most common cause Excessive fluid loss from perspiration More likely in warm weather sports Loss of sodium When a muscle is contracted long time Isotonic contraction

Cramps are also very common at REST especially in older adults. This kind of muscle cramps often occur during the night (NOCTURNAL CRAMPS) in calf muscles or toes. CAUSES ¿? The actual cause of night cramps is unknown OTHER POSIBLE CAUSES Medications: Numerous medicines can cause cramps (furosemide, donepezil…) Vitamin deficiencies: Several vitamin deficiency states may directly or indirectly lead to muscle cramps (thiamine) Poor circulation: It happens in legs (calf muscles) in inadequate oxygen to the muscle tissue and can cause severe pain in the muscle.

What we should do to prevent muscle cramps?  AVOID DEHYDRATION: Drink plenty of liquids every day. Fluids help your muscles contract and relax and keep muscle cells hydrated and less irritable. Drink fluids before any exercise activity. During the activity, replenish fluids at regular intervals, and continue drinking water or other fluids (with minerals) after you're finished.  STRECHT THE MUSCLES: Stretch before and after you use any muscle for an extended period (even before bedtime if the individual has night cramps)

South African study of ultra- distance runners Competition:Competition: Two Oceans Ultra-marathon (56km). Cape Town Aim:Aim: No link between hydratation and cramps Subjects:Subjects: 72 male runners 45 had previous27 had no previous Process:a)Process:a) Weight: Before and after the race b) b) Blood samples [Glucose, protein, sodium, potassium, calcium…]: Before, inmediatly after and 60 min after

Results:Results: a) a) 21 of the 45 (they had) suffered cramps b) 22 of the 27 (the didn’t have) suffered cramps Keys:Keys: a)When: latter half of the race or inmediatly latter finish b)Muscles affected: 1. Hamstrings (48%) 2.- Quadriceps (38%)

c) No difference in the body weight d) No difference in hydration status e) [Na+] and [Mg]

Conclusion: The researchers do not suppor the common hypothesis and think that they have to search an alternative to explain the cause.