CARBOHYDRATES
Optimal fuelling for exercise depends on
your type of training. “We generally tend to
use a mix of both carbohydrates and fats to
fuel exercise up to maximal intensities across most intensity levels,” says dietitian
Margaret Mielczarek. “As exercise intensity increases, we shift from predominantly
using fats to fuel exercise towards predominantly using carbohydrates to
fuel exercise.”
Your need for pre- or post-workout carbs depends on duration and intensity
at which you train; low-intensity workouts tend to use fat as their predominant
fuel source, they don’t often need additional nutrition as fuel or for recovery.
However some ‘topping up’ of glycogen stores may be necessary in the morning
or afternoon when your blood glucose is at a fasted level. “Topping up your
glycogen stores, which deplete slightly after an overnight fast, is important to
ensure adequate supply of carbs for energy,” says Mielczarek. “And if training in
the afternoon a while after eating, again you have a small snack to top up glycogen
stores so that you have plenty of fuel to burn for energy.” According to the
Australian Sports Commission, the amount of carbohydrates recommended for
pre-training fuel is 70 grams for most athletes. The amount of glycogen you have
already stored in your muscles is also dependent on your diet overall. Consuming
a diet with adequate carbohydrates will ensure that there is plenty of glycogen
available. “We typically recommend that about a quarter of your plate should
be complex carbohydrates,” says Mielczarek. “It’s important to opt for complex
carbohydrates such as brown rice, quinoa, sweet potato, pumpkin and corn, or
even fruit, dairy and nuts.”
With adequate carbohydrate intake, we usually have enough energy stored
to last for 60 to 90 minutes without ‘bonking’ or hitting the wall. “Interestingly,
the longevity of our carbohydrate stores is generally independent of intensity of
exercise,” says Mielczarek. Daily carbohydrate needs should be adjusted depending
on your training. According to the Australian Institute of Sport, low-intensity
exercise requires around three to five grams of carbohydrates per kilogram of
body mass. Moderate exercise for approximately an hour a day ups these needs to
five to seven grams and endurance athletes training from one to three hours in a
given day need around six to 10 grams. Pre-workout snacks generally consist of
one to four grams of carbohydrates per kilogram of body mass.
If training extends past the limits of your carbohydrate stores (snack or no
snack), your body will eventually opt to burn fat. According to studies published
in Sports Medicine journal, the rate depends on duration and exercise intensity,
but as a general recommendation, exercise going for one to two hours should be
supplemented with 30 grams of carbohydrate (for the second hour, naturally)
and two to three hours of exercise with 60 grams per hour, which is technically
the maximum rate the body can break down a single source of carbohydrates. Acalories is more important than the quantity,
with the right types of food helping to reduce
cravings, increase energy levels and manage
hunger – all the conditions indicative to
fat loss.
“I stand by the fact that I can put clients
on a calorie surplus eating the right type of
food, and they will still lose fat while gaining
muscle – a calorie from a breast of chicken is
very different from a calorie from a chocolate
bar. They might not lose ‘weight’ but they will
lean out,” says Sharpe.
“For example, if you load up on sugar all
the time, you are going to become resistant to
insulin and to leptin, which is your hunger-
regulating hormone. By eating the correct
foods, you will have an internal balance that
ties into everything you do on a daily basis –
including your body composition.”
ROCKET
FUEL
TO MAKE YOUR
NUTRITION WORK
FOR YOUR GOALS,
YOU NEED TO
UNDERSTAND HOW
YOUR BODY USES
WHAT GOES IN
YOUR MOUTH.