Modern Athlete Magazine Issue 125, December 2019 | Page 61

COACHING
BODY SCIENCE
Cramping your style?
In spite of modern science, the jury is still out on the causes of
muscle cramping, although several theories of yesteryear have
been thrown out. – BY SEAN FALCONER
F
or many years, it was believed that cramping was
caused by heat, dehydration, or a lack of salt and
minerals in the body, but study after study has ruled
out all of these factors. “Although the idea that mineral
deficiencies and dehydration can cause cramps have been
popular, we have done many, many studies that do not
prove these as causes for cramps during exercise,” says Dr
Martin Schwellnus, professor in sports medicine and exercise
science in the Faculty of Health Sciences at the University
of Cape Town, who is considered one of the world’s leading
researchers in this field. Instead, the growing research on
cramps points to muscle fatigue and failure in the neural
communication pathways of the muscles as the cause of
cramping.
As an athlete, you train a muscle to contract so that you can
run, but this fatigues the muscle. It then begins to ‘short-
circuit’ and stays contracted when it shouldn’t, causing a cramp. “The mechanism for
muscle fatigue and muscle damage causing cramping is best explained through an
imbalance that develops in the nervous system control of muscle. Muscles tend to
become very twitchy when they become fatigued or are injured,” says Dr Schwellnus.
So what this means is that to stop cramps, you just need to get fitter before racing...
but that’s not going to help you much when a cramp stops you midway through a race.
If that happens, there is only one thing you can do: Stop and stretch! Static stretching,
in effect, breaks the cramp, and once you achieve that, you must start slowly and
gradually build up your speed again. (And eating a banana to break a cramp is just an
urban legend!)
Then, after the race, adapt some of your training runs so that they are done at the
same pace you intend racing, including accelerating in the second half of the run and
throwing in that fast finishing effort that many of us inevitably put in at races. You
may still get some cramps, but you’ll be fitter, faster and better prepared to race - and
besides, cramping in training is much better than cramping in a race!
NUTRITION
Potato Power!
The mighty potato has always been an aid to the
endurance athlete and it has more benefits than we
realise. All you have to remember is how you prepare your
potato-based meal and what kind of potatoes can benefit
you when. – BY SALOME SCHOLTZ, REGISTERED DIETICIAN
I
t may come as a surprise to hear that one medium-sized boiled potato with
the skin contains about 45% of the daily recommended value of vitamin
C, and as much or more potassium than bananas, spinach or broccoli. It
also accounts for 10% of the daily value of vitamin B6 and trace amounts of
thiamin, riboflavin, folate, magnesium, phosphorous, iron and zinc.
Regrettably, however, we tend to consume potatoes as oily fries, or potato
chips, and baked or boiled potatoes are generally dressed in fats like cheese
sauces, butter or sour cream. To get the most out of the power of this delicious
veggie, it’s important to get rid of the frills. Instead, we can focus on the three
types of potatoes that we South Africans are used to, and what athletes need
to note if they’re fuelling for a long run or ride.
Keeps You Going
Most of us are familiar with white (or yellow) potatoes, new (baby) potatoes
and sweet potatoes. All of these varieties contain roughly the same amount
of vitamins and minerals, but potatoes differ from one another in their starch
content and type, which affects not only how fast they’re digested, but how
they act when cooked.
• Boiling usually results in a lower glycaemic index (GI), since starch can bind
with water. The dry heat of baking, on the other hand, lowers moisture and
concentrates the sugar in the potato. Keeping the skin on will also contribute to
a lower GI as the fibre in the skin helps to decrease the rate at which the sugar
is absorbed into the blood after digestion.
• White potatoes, whether you have them mashed, baked, as fries or potato chips,
have a high GI, which means that their carbohydrates are quickly turned into sugar,
which elevates your blood sugar levels quickly after they have been consumed.
• New potatoes are any potatoes which are gathered young, just before their sugars are
completely transformed into starch. It is due to this that they have an intermediate GI.
• Rich in vitamin A and beta-carotene, the sweet potato offers complex
carbohydrates (due to a higher fibre content) along with antioxidant nutrients. Boiled
sweet potatoes also have a low GI.
Refuel, Replenish
It is important to fuel every 45 to 60 minutes during a long run or ride or run
of 90 minutes or more, with around 30g to 60g (three to four new potatoes) of
carbohydrate per hour. Out of the potatoes mentioned above, the new potatoes
will do the best refuelling job, as they have an intermediate GI and are easier to
consume and digest - due to their lower fibre content. The intermediate GI will not
only provide you with a quick surge of energy, but will assure that you have sustained
energy levels for longer. By adding a little salt, you can
also help to replace sodium lost through sweat.
New potatoes can also be
consumed as your
starch after the race to
help with refuelling of
your carbohydrate
stores.
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