recent study published in Sports Medicine
journal found that a carbohydrate mouth
rinse could improve performance for exercise
of shorter duration and higher intensity
(for example, an hour at 75 per cent of VO2
max). The science: putting something in
your mouth activates areas of the brain that
respond to gustatory (taste) stimulation and
act with an appropriate emotional, cognitive
and behavioural response.
FATS
Some athletes seek to become more ‘fat
adapted’ by severely limiting carbohydrate
intake. “Fat adaptation usually requires an
athlete to go on a really low carb diet, less then
25 to 50 grams per day, to get their body to go
into ketosis, thereby burning ketones as the
fuel source,” says Mielczarek. This is the same
principle behind the ketogenic diet, but unless
your goal is rapid weight loss, fat adaption can
be of limited use.”
“Becoming fat-adapted may have some
disadvantages,” says Mielczarek. “The
body has two energy systems it can use –
carbohydrate breakdown and fat breakdown
- so why wouldn’t we want to use both?
“Those who are going to great lengths
to be fat-adapted (and only use fat as their
energy supply by omitting all carbohydrates)
are limiting their fuelling options and
compromising their ability to sprint, surge
or go at intensities which require quick
breakdown of energy.”
At lower intensities the body can
efficiently use fat as a primary fuel source.
“Carbohydrates provide fuel for working
muscles because there is little oxygen available
to utilise fat, as fat burning is an oxidative
process,” says Mielczarek. Studies have
shown that by consuming a higher fat diet,
the body can become more used to using fat
as fuel. A study published in the Journal of
the International Society of Sports Nutrition
found that a high-fat diet (more than 1.3
grams of fat per kilogram of body weight per
day) not only performed better – a higher
one-rep maximum bench press – but also had
higher resting energy expenditure. Regardless
of your goals, fats should comprise around 30
per cent of your daily caloric intake.PROTEIN
According to the Australian Sports
Commission, an inactive person needs to eat
around 0.8 grams of protein per kilogramof body mass, simply to maintain muscle.
For athletes who are consistently repairing
exercise-induced muscle damage, the
requirements increase (this is across all sports,
not just strength training). To both repair
and grow muscles, the body needs around
one to two grams of protein per kilogram
of muscle mass. Because protein is about
balance (rather than storage), it’s important to
ingest good protein at every meal rather than
just before and after the gym. The Gatorade
Sports Science Institute recommends eating
20 to 25 grams of protein at every meal as
well as immediately after exercise. Ingesting
protein after training is important but there
are benefits to ingesting protein prior to a
session as well. “You want to start repairing
muscle straight away, so it’s important that you
have adequate protein in your system during
training as well as after,” says Meilczarek. A
recent study in Sports Medicine journal found
that exercise could reduce blood flow to the
gut, so nutrient absorption from recovery fuel
can be compromised. To combat the effect,
eat a small dose of protein prior to exercise.
How much? One study from the Journal of
Nutrition found that the ingestion of both
protein and carbohydrates (0.15 grams of both
per kilogram of body mass) prior to a bout of
resistance exercise increased protein synthesis
(anabolism) by 48 per cent during exercise,
and an additional 19 per cent after exercise.AFTER THE FACT
The optimum time for recovery fuel is within 30 to 60 minutes post
workout. “Adequate refuelling after exercise is important to replenish
glycogen stores and to allow muscles to repair, recover and adapt to the
exercise that you have just done,” says Mielczarek. “But you don’t have
to refuel after every exercise session; any training of low to moderate
intensity that lasts for up to 60 minutes may not need any additional
nutrition, and resuming normal eating will be generally enough to refuel.”
When training for longer periods, “enjoy a snack or meal that consists
of protein, healthy fats and carbohydrates,” says Mielczarek. Our bodies
hold our macronutrients in fairly equal stead when it comes to recovery
and refuelling. “Pre- and post-workout snacking doesn’t vary that
much...we generally recommend about 15 to 25 grams of protein and
one gram of carbs per kilogram of body weight after a heavy training
session; our bodies don’t use any more than 25 grams of protein in
recovery and any extra will typically get stored as body weight.”
The role of protein in this instance is to repair exercise-induced
muscle damage, which prevents muscle soreness and encourages
hypertrophy. Breaking down this protein into amino acids the body can
use takes energy, so by co-ingesting protein and carbohydrates you are
guaranteeing you’ll get the most out of both.