Defined as ‘painful involuntary skeletal muscle contractions’, muscle cramping is a common and unwelcomed complaint among many athletes.
Exercise related muscle cramps (ERMC) typically occur in athletes who compete in long distance endurance events, multi-day events and high intensity sports including triathlon, marathon, footy, cycling and tennis. Muscle groups where cramps occur are usually in the quads, hamstring and most commonly the calf.
Despite how common cramping is, evidence is mixed as to how cramps occur and how to prevent them. ERMC has been attributed to factors such as
- Electrolyte imbalance
- Untrained endurance fitness
- High BMI
- Shorter daily stretching time
While no one can pinpoint the exact cause, most scientists agree that ERMC can be attributed to muscle fatigue and altered neuromuscular function. The result? Abnormal stimulation of the muscle and autonomic (just happens) muscle contraction. Ouch!
Using this theory, the nutritional strategies listed below decrease the likelihood of cramping by decreasing muscle fatigue. Use them in combination with other recovery techniques and you’ll hopefully experience less discomfort and cramping during and after your training, sports or events.
MUSCLES LOVE CARBS.
Making sure the muscles are supplied with sufficient usable energy is the best way to avoid muscle fatigue. Carbohydrates are the preferred fuel source of the body for exercise, and one major storage area is within the muscle as glycogen. It therefore makes sense to eat sufficient carbs to ensure your muscles can perform the work, especially when exercising at high intensity or for long periods of time (>90 mins).
- Have a small carbohydrate-based snack 1hr prior to exercise such as a piece of fruit (e.g. a medium apple of banana) or ½ English muffin.
- If you’re exercising for a long period top up your carb stores each hour with additional fruit, gels, or lollies to help prevent premature muscle fatigue and cramps.
The theory of dehydration is a common explanation for why muscle cramping occurs. Although there is little evidence directly relating muscle cramping to dehydration, we do know that losing 2% or more in body weight fluid during long or high intensity exercise is a recipe for decreased concentration and performance. Additionally, dehydration places an increased stress on the heart because blood becomes thicker and harder to pump out. It is therefore important to keep up adequate fluid intake before, during and after exercise to reduce stress on the heart and decrease the likelihood of muscle fatigue or cramping. The amount of fluid you need will be highly individual as sweat rate varies considerably, so be sure to talk to a Dietitian to figure out your specific needs if you’re prone to cramping.
- Ensure you are hydrated BEFORE exercising. An easy way to tell is to just aim for clear urine.
- Drink regularly. 100-200ml every 15min increases absorption of fluid.
- Consume an electrolyte formula or sports drink such as Gatorade during long and intense events or games.
The fluid we sweat not only removes water from our bodies, but also electrolytes including sodium, chloride, potassium and magnesium. Electrolytes play a critical role in muscle contraction/relaxation and nerve transmission, so any interruption to this balance could lead to complications. Some studies have found ‘salty sweaters’ cramp more often, however literature is inconclusive.
Replacing electrolytes lost through sweat, especially athletes who have a high salt sweat concentration, may be helpful during sports or events. The exact amount you need will depend on sweat rate and sweat sodium concentration which do vary based on exercise duration, intensity and environment, so it’s a good idea to be tested under conditions similar to your race or event day.
- Have a salty carb snack, such as pretzels before exercise. This may also encourage fluid intake to keep you adequately hydrated.
- Adding a pinch of salt to your sports drink may assist with keeping salt levels up however doesn’t taste incredibly fantastic.
- Decrease your bodies excretion of salt in the first place. It has been suggested that a LOW salt intake away from exercising may decrease the concentration of salt in sweat – meaning perhaps less need to replace large amounts during exercise.
SUPPLEMENTS / TREATMENT
Here are a few supplements and treatments that may assist with muscle cramps:
- Quinine: has been used to treat cramp frequency and intensity however can be dangerous and even lead to fatality in large doses.
- Magnesium is often used to prevent recurrent cramping. Some people respond, others do not. A diet rich in leafy greens, legumes, seafood (tuna, salmon) and wholegrains will ensure adequate magnesium stores in most people.
- A small ‘shot’ (30-60ml) of Pickle Juice has been found to relieve cramps within 35 seconds. Its speculated that pickle juice triggers a reflex which inhibits neuromuscular activity in cramping muscles.
TAKE HOME MESSAGE
With multiple theories on how muscle cramps occur, there is no single answer for relieving or preventing cramps. It’s best to tackle the issue from multiple angles using the nutrition strategies listed above, but also being mindful of other prevention strategies such as
- Stopping exercise at the onset of the cramp
- Being adequately trained for your event or sport
- Massage therapy
- Heat acclimatisation
- Active and passive stretching
And lastly, if cramping is ongoing and debilitating to your performance, see your Dietitian for an individually considered nutrition and hydration cramping strategy.