The document discusses the body systems used in competitive swimming, specifically for the 400m freestyle event. It summarizes that the skeletal, muscular, respiratory, circulatory, and energy systems all work together during this event. The skeletal system provides the framework for movement, while the muscular system contracts to power strokes and kicks. The respiratory and circulatory systems work to oxygenate muscles and remove waste. Finally, the energy systems provide ATP to fuel short bursts initially, then rely more on anaerobic and aerobic pathways over the duration of the race. Proper hydration is also essential to maintain performance.

1. Body Systems Used In
Swimming (Freestyle)
By: Dylan Harrigan

2. Skeletal System
In swimming it is a commonly known fact that swimming is a non-weight
bearing exercise therefore very little stress is placed on the bones. But if we are
talking technically, every bone is used as all parts of your body needs to be
moving to stay afloat. I am going to focus of the Middle distance freestyle
events.
BONES
The main bones that are used when swimming freestyle from top to bottom are
the bones of the shoulder girdle and arm which is used when rotating the arm
over to complete the stroke, using the ball and socket joint, hinge joint and
saddle joint. The bones used here are the clavicle, humerus, radius and the
ulna.

3. Skeletal System
Next down the body is the bones of the leg which include the Femur, Tibia and
Fibula. These bones are used along with the hip joint, knee joint and ankle joint
to kick your legs to propel the rest of your body through the water. The legs are
the most important part of the freestyle stroke.

4. Swimming Freestyle

5. Muscular System
Fast or Slow Twitch?
When swimming the 400m Freestyle event, you use your Fast Twitch-A system
or FT-A. FT -A fibers have a large motor neuron and fiber diameter, a high
mitochondrial density, a medium capillary density, and a medium myoglobin
content.

6. Muscular System

7. Muscular System
Swimming puts enormous amounts of stress on the muscles. The muscles
used in swimming are:
● The muscles in the upper limb which includes the thenars, brachioradialis,
flexor digitorum profundus, biceps, triceps and the deltoids.
● The neck muscles, which is the sternocleidomastoid muscle.
● The front trunk muscles, which is the pectorals, serratus anterior, external
oblique and the rectus abdominis.

8. Muscular System
● The back trunk muscular group, which is the latissimus dorsi, trapezius,
spinus erectors, teres major, teres major, rhomboid major and the
rhomboid minor
● The muscles of the lower trunk, which is the gluteus maximus and the
abductor magnus
● Finally there is the muscles of the lower limb, which includes the
quadriceps, hamstrings, gastrocnemius, tibialis anterior, abductor
hallucius, abductor digiti minimi and the flexor digitorum brevis.

9. Muscular System
These muscle groups all work as one to make one major functioning body, The
muscles work together to propel your body through the water. For example, as
you roll your arms over, you are using the deltoid muscle, then as you continue
on the stroke as it enters the water, you stretch your stroke, using the
latissimus dorsi and the pectoralis major. Then as you are pulling yourself
through the water, you dip your forearm, then pull the water, which uses the
biceps brachii. As you roll yourself over to do another stroke, you are using
your core muscles. Whilt doing this you are continuously pumping your legs,
making sure you are kicking from the hips, putting a large amount of pressure
on the gluteus maximus and the quadriceps.

10. Muscles Used Whilst
Swimming

11. Energy Systems
Swimming the 400 metres freestyles in an extremely enduring event. One
which is feared greatly by the swimming community because of it’s difficulty.
The aim of the event is to break it down into 100’s. The swimmer strives to go
out the first 100 at pb + 2-3 (your best 100 time + 2-3 seconds) then holding the
next 200 metres at around pb+6 before maxing out the last 100, giving all you
got left and bringing the race home. At the beginning of the race you use your
ATP System, using short, fast bursts of energy, before your anaerobic or ATP
PC system kicks in. This is between the 1 minutes stage of the race until about
the 3 minute 30 mark. After that for the final parts of the race you would use
your aerobic energy system. An average 400m freestyle swim at my age would
sit around the 4 minutes 30 mark, sitting it in the Anaerobic zone for the
majority of the race.

12. Energy Systems
“Correct use of the training principles will create superior organization and more
functional content, means, methods, factors, and training concepts.”

13. Respiratory and Circulatory
Systems
Swimming is a form of aerobic exercise that strives on the improvement of
strength, flexibility, coordination and balance. Swimming is known to improve
the circulatory (or cardiovascular) system gravely. Swimming on a regular basis
can improve heart contractility, decrease blood pressure, lower heart rate and
improve lung efficiency.
When swimming, it is a must to be efficiently breathing. Whilst swimming the
400 Freestyle, it is recommended that the swimmer breathes every 3-4 strokes,
depending on their preference. Each time a person breathes their diaphragm
contracts and downwards increasing the space in the chest cavity. As your
lungs expand and air is sucked in through your nose or mouth, which the air
then travels down your windpipe and into your lungs.

14. Respiratory and Circulatory
Systems
The air will then continue through the bronchial tubes before finally reaching the
alveoli (air sacs). Through the extremely thin walls of the alveoli, oxygen from
the air passes passes to the surrounding capillaries (blood vessels) which then
a protein called hemoglobin helps move the oxygen from the Alveoli to the
blood. Whilst this is happening, the carbon dioxide moves from the capillaries
to the alveoli.
The oxygen then attaches to the red blood cells, enters your heart and then
flows in your bloodstream to your organs, muscles and body tissues. When
your blood returns to the lungs, the carbon dioxide is released from the
bloodstream into the air that you exhale.

15. Respiratory and Circulatory
Systems
Since swimming is an aerobic exercise, your body requires increased amounts
of oxygen, which then helps turn stored fat into energy.
It is a known fact that swimmers’ hearts pump more blood with every beat.
Blood circulation is a crucial function in the body. It supplies the much needed
oxygen to the brain and other organs, which in turn is what makes our bodies
work!
Muscles in your body metabolise glucose (sugar) in your bloodstream, breaking
it down and taking it in to create a high energy molecule known as ATP, which
is extremely important for cells functioning. Part of this process demands
oxygen to fully deteriorate the glucose so when you need more energy
metabolised, you'll need more oxygen too.

16. Respiratory and Circulatory
Systems
If you don't get enough oxygen, your muscles will not be able to fully break
down available glucose, in retrospect, becoming fatigued and producing lactic
acid instead, giving you a sore, sluggish feeling.
In swimming, to train hard and hit correct times, you need to control your
breathing. It is calculated to add on 0.25 seconds on top of your final time each
breath. Also, breathing plays a major role in maintaining fatigue, turning the
lactic acid that has built up and using it as an energy boost.

17. Respiratory and Circulatory
System

18. Hydration
Hydration, alongside recover and breathing, is a vital part of maintaining peak
performance during training and when competing. Unless fluid losses are
replenished whilst exercising, the athlete will start to dehydrate. Dehydration
decreases training performance by;
● increased heart rate
● impaired heat regulation
● increased perceived exertion (i.e. exercise feels harder
than usual and the athlete fatigues earlier)
● reduced mental function
● reduced skill level
● stomach upset

19. Hydration
All levels of dehydration damage performance and the magnitude increases as
the degree of dehydration increases. In order to keep from becoming
dehydrated, the athlete must consume as much fluids as they are loosing
during sweat. Sports drinks are the preferred fluid to consume during exercise.
Sports drinks are flavoured therefore encourage a greater fluid intake. The
carbohydrate and electrolytes in sports drinks promote better fluid absorption.
The carbohydrate also provides a fuel source. Other fluids such as water,
cordial and juice may be suitable when exercise intensity is low.
Seeing as whilst swimming, you produce more sweat than any other single
sport, you need to make sure you are hydrated to keep on pushing through
high intensity training.

20. Hydration
During exercise it is estimated that you lose 1kg through sweat. It is essential
to replenish this weight lost by drinking 1 and a half times that amount of fluids,
whether it be a sport drink, water or some form of protein drink.
Before a race, especially the 400m freestyle you need to make sure you are
hydrated again by drinking sports drinks. As having past experience in this
event I advice powerade as it is the fluid that I drink and it really does work!
When swimming, because the training goes for roughly 2 hours, it is
recommended that you drink a specific sports drink such as powerade or
staminade. In doing this, not only will you be rehydrating yourself, you will also
be replenishing the lost electrolytes and carbohydrates.

21. Hydration
A good way to test whether you are hydrated is through your urine, the lighter
to pee the more hydrated, the darker the more dehydrated you are!
After training you need to rehydrate yourself even more, because you sweat a
lot when you finish training as your body is still trying to cool itself down. I do
this by having a protein shake, which also helps with the recovery of your
muscles at the same time.
All in all, you NEED to be hydrated to race at peak performance!

22. Bibliography
● http://www.livestrong.com/article/334540-effects-of-swimming-on-respiratory-system-of-humans/
● http://www.swimtoslim.com/2010/12/muscles-used-swimming/
● http://www.nhlbi.nih.gov/health/health-topics/topics/hlw/whathappens
● http://www.google.com.au/search?q=whats+the+circulatory+system&oq=whats+the+circulatory+system&aqs=ch
rome..69i57j0l5.7374j0j7&sourceid=chrome&es_sm=122&ie=UTF-8&gws_rd=ssl&safe=active&ssui=on
● http://www.google.com.au/search?q=whats+the+respiratory+system&oq=whats+the+respiratory+system&aqs=c
hrome..69i57j0l5.5104j0j7&sourceid=chrome&es_sm=122&ie=UTF-8&gws_rd=ssl&safe=active&ssui=on
● http://www.vitalproteins.com/blog/blood-circulation-important/
● http://healthyliving.azcentral.com/effects-exercise-respiration-9234.html
● http://health.howstuffworks.com/wellness/diet-fitness/exercise/sports-physiology8.htm
● http://hes.ucfsd.org/gclaypo/skelweb/skel01.html
● www.innerbody.com/image/musfov.html
● en.wikipedia.org/wiki/Energy_system