Unit 12 – Nutrition
Assignment 3 – Weight Change
Energy balance can be explained using this equation: Energy In = Energy Out
This balance would result in stable weight, shown by the blue scales diagram. If energy
expenditure exceeds energy in, then this would result in weight loss (pink diagram), and if
energy in exceeded energy expenditure, then this would result in weight gain (green diagram).
Out In
In Out
In Out
Weight Loss Stable Weight Weight Gain
Each individual has their own energy requirements due to their daily activities, and their weight.
This can be calculated by adding the basic energy requirements and the individuals extra energy
requirements. P4
Basic Energy Requirements includes your Basal Metabolic Rate, which is the minimum amount of
energy required to maintain vital functions within the body, and any general daily activities.
For every kilogram of body weight, 1.3 calories is required every hour. For example, I weigh
58kg, so I would require 1.3 x 24 (hours) x 58 (kg) = 1809 calories per day.
Extra Energy Requirements are the extra amounts of energy needed for the demands of extra
exercise for example training, or matches. In general, for each hour of exercise you require an
additional 8.5 calories for each kilogram of body weight. So for me to play netball for an hour,
would require 8.5 x 1 (hours) x 58 (kg) = 493 calories per day of training.
Therefore, on a day of training, I would need 1809 calories + 493 calories, which would equal
2302 calories per day. P4
The athletes training and competing increases their personal energy requirements per day, so to
maintain their energy balance, the correct amount of calories will need to be consumed to meet
their needs.
, If not enough calories are consumed in their diet, this will lead to weight
loss and a deficiency of nutrients and energy which are essential for their
Out
sporting needs. This will create low glycogen stores meaning the athlete will
In feel constantly tired, and they will become more prone to injury and illness.
It will also affect their performance. For example, if a netball player was
not consuming enough calories to meet their energy demands, then they
would feel tired. When playing a game against an opponent who was full of
Weight Loss energy, they would struggle to keep up, as their muscles would not be able
to contract as well. This would hinder their personal performance, as they
would not look as good, but it would also hinder their team’s performance as
they would not be able to rely on this player as someone to pass to, or as a
defender, as they would struggle to keep up with their opponent. P4/M2
If too many calories are consumed in their diet, this will lead to weight gain
and an excess in nutrients needed. This will create a fat store, because
In most unused nutrients get stored as fat. As fat does not metabolise, this
will just sit there, providing an athlete with unnecessary weight. This would
Out make it harder to perform in most sports, because it will be harder to carry
the excess weight around. If playing netball, a player would struggle to keep
up with a leaner, lighter opponent. This would hinder the team’s
performance, as again, they would not be able to rely on this player as
Weight Gain
someone to pass to or to defend, because they would just not be able to
keep up with their opponent. P4/M2
Weight loss or weight gain will mean the performer won’t be able to train as intense and for as
long, they will become less agile, aerodynamic, pace and speed will decrease and the performer
will fatigue much more quickly. The performer will plateau or reverse their progress, they will
be less effective and performance/ability levels altogether will decrease. P4/M2
There are factors that affect the individual’s sporting performance:
Basal Metabolic Rate - the more efficient your body is the higher your basal metabolic rate,
because energy is used up more quickly. If you have a fast metabolism, then you need to ensure
that you consume enough calories, and if you have a slow metabolism you need to ensure that not
too many calories are consumed. This is all to ensure that you maintain energy balance and good
sporting performance. P4/M2
