Natick High School Fitness

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Why is fitness important?

Fitness is defined in many ways. It is the condition of being physically fit and healthy, or the quality of being suitable to fulfill a particular role or task, and even an organism's ability to survive and reproduce in a particular environment. However, the definition of fitness comes down to one word. Health. Fitness is acheived through physical activity, exercise, and correct nutrition.

At Natick High School, the goal of Physical Education is to encourage students to develop an individual optimum level of physical fitness, acquire knowledge of health-related fitness concepts, and understand the significance of lifestyle choices on one's health and fitness. Through multiple fitness experiences, students will become more responsible for and develop an appreciation of lifelong fitness strategies.

Here on this site, you will learn about the various muscles that are used to stay healthy and fit, how food works throughout your body to give you energy, and which foods will give the best results. Being physically fit will help you give you more energy throughout the day, will get you stronger and more focused, and lower the risk of disease and illness.

There are many benefits that come with exercising and being fit. Here are some example: more energy, better night’s sleep, increases mental focus, decreased risk of a heart attack, reduce the risk of some kinds of cancer, increased strength and stamina, reduced depression, decreased stress levels, improved digestion, enables weight loss and keeps it off, burns extra calories, alleviates menstrual cramps, and brain benefits!!!


There are three types of muscles: skeletal- biceps, triceps, quadriceps; cardiac- heart; and smooth-digestive system and other involuntary muscle tissue. Muscles are classified by shape, size, latin name, origin or insertion (location), and action.

There are also two types of muscle fibers: fast-twitch and slow-twitch. There are many types of muscles, here are a few examples:

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Forms the rounded contour of the shoulder. There are three parts: the front portion, the middle portion, and the posterior portion. The middle portion abducts the arm at the shoulder, and the posterior portion laterally rotates and extends the arm at the shoulder.


The trapezius is a large superficial muscle on the back that vontrols shrugging the shoulders up and down, and drawing the shoulder blades together. The strain on trapezius is often the cause of lower neck pain.

Latissimus Dorsi

The lats are triangular shaped muscles that covers the lumbar part of the back.

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The pectoralis is a thick muscle that covers the anterior (upper front) part of the chest.


This muscle located on the upper arm. It is tri-articulate, meaning that it works across three joints: the shoulder joint, elbow joint, and proximinal-radioulnar joint.


The tricep is a large muscle that runs along the back of the upper arm. It is an extensor muscle (opens at a joint) and works in coordination with the biceps which are flexor muscles (bends at a joint).

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Rectus Abdominis

The rectus abdominis extends from front of the ribs to front of the pelvis. It's main job is to flex the spine forward and is well known as "6-pack abs" which comes from a very strong rectus abdominus

External Obliques

There are three of them on each side of the rectus abdominus. They allow the trunk to twist, but to the opposite side that the muscle contracts (unique characteristic of that group of muscles). It assists with exhalation and supports the organs inside the body cavity.

Gluteus Maximus

The gluteus maximus makes up shape and appearance of the buttocks. It also maintains the trunk in the erect posture.

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The quads include the four major muscles on the front of the thigh (quad=4). It is the extensor muscle (muscle that opens a joint) of the knee. It is crucial for walking, running, squatting, and jumping.


The hamstrings begin just underneath the gluteus maximus and attach to the tibia. The primary function is knee flexion (bringing the heel towards the buttocks). When exercised without being stretched, hamstring injuries (strains, pulls, etc.) are very common.


The calves are the muscles at the bottom of the leg. Their function is to stabilize during walking, running, and jumping.

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Digestive System

Digestion involves the breaking down of food into smaller pieces, the mixing of food, the movement through the digestive tract (GI tract), and the chemical breakdown of the large molecules of food into small molecules. Think of it as a “disassembly line" where the food is broken down by separate organs.

Digestive Process:

Ingestion - taking in food
Propulsion - swallowing food and peristalsis
Mechanical Digestion - chewing, churning, physically prepares for chemical digestion
Chemical Digestion - complex food molecules are broken down into their chemical building blocks
Absorption - passage of digestion end parts (plus vitamins and minerals) to the blood and lymph
Defecation - elimination

Learn more about the and the organs within.

Parts of the GI Tract

In the mouth, the teeth bite off and chew food into a soft pulp that is easy to swallow. The saliva moistens food, starts to break down starches slightly acidic.

The esophagus is a muscular tube, runs from mouth, through the neck, into the stomach. It uses waves of muscle contraction called peristalsis to push the food down the throat.

The stomach is the thick muscles in the wall, used to contract to mash food into a mixture called chyme the stomach lining produces strong digestive juices.

The small intestine is narrow. but long (20 ft). The enzymes continue the chemical reactions on the food and the nutrients broken down small enough to pass through the lining of the small intestine and into the blood (diffusion).

The large intestine is useful for substances that were not absorbed in the small intestine, such as spare water and body minerals. They are absorbed through the walls of the large intestines into the bloodstream. The remains are formed into brown. semi-solid feces, ready to be removed from the body.

The rectum and anus are the end of the large intestine and the next part of the tract. The rectum, stores the feces and they are finally squeezed through a ring of muscle, the anus, and out the body.


A nutrient is a chemical substances in food that builds, repairs, and maintains body tissues, regulates body processes, and provides energy. There are two types of nutrients: macronutrients and micronutrients. Macronutrients contain calories and are carbohydrates, fats, and protein. Micronutrients do not contain calories and are vitamins, minerals, and water.


Calories are a unit of energy. Carbohydrates contain 4 calories per gram and provide the main source of energy to muscles nerves and brain, and are a good sources of fiber. They can be found in bread, cereal, beans, fruits, and vegetables. There are two types of carbs: simple and complex. Simple carbs enter the bloodstream quickly and are a quick source of energy. Examples of this are soda, cereal, icecream, fruit juice, high sugar, fruit, and syrup. Complex carbs enter blood stream slowly and are long lasting sources of energy. Examples of this are whole grain, brown rice, brown pasta, baked and sweet potato, yams, broccoli/other vegetables, and apples.

Fats contain 9 calories per gram and are used for sources of energy, to make vitamins usable, to cushion and protect internal organs, and add taste and texture. Not all fats are bad; there are three types of fats: saturated, unsaturated, and trans fats. Saturated fats contribute to cholesterol and are commonly in milk products and egg yolk, butter, lard, shortening, and animal red meats. Trans fats are found occurring naturally in animal products but also results from processing of fats. USDA reports many studies where trans fats were linked to increases in cardiovascular disease, obesity, and type 2 diabetes. The government recommends 0g in a diet. Unsaturated fats are good for you; they increased HDL (good cholesterol), decreased risk or cardiovascular disease, are a good energy source, and help with vitamin absorption.

Protein contains 4 calories per gram and rebuild, repair, and maintain body tissues. They help fights infections, makes blood strong, and forms muscle, bone, blood, cell membranes and hormones. Sources include tuna, chicken, milk, and eggs. There are two types of proteins: complete and incomplete. Complete proteins contain all essential amino acids. Incomplete proteins do not contain all essential amino acids. Amino acids are the building blocks of proteins, there are 20 amino acids: 11 produced by the body and 9 essentials that need to be supplied by diet.


Vitamins are organic substances that occur naturally in foods. They activate chemical reactions in the body essential for growth, repair, energy, metabolism and health. There are two types: fat soluble A,D,E and K (can not be stored), and water soluble B and C (able to be stored). Examples of sources are animal tissue, veggies, fruits, fortified foods(manufactured w/ vitamins in them). However, cooking, exposure to alkaline, exposure to light, excessive processing and packaging REDUCE the vitamin content.

Unlike vitamins, minerals are not destroyed by heat, light, acidity, or alkalinity. They regulate many chemical reactions in body. Major types of minerals are calcium, magnesium, phosphorous, potassium, and sodium. They come from both plant and animal sources and are generally are more reliable from animal sources.

Water makes up between 45-75% a person’s body weight. It is 2/3 intracellular fluid (fluid within tissue cells) and 1/3 extracellular fluid (fluid outside tissue cells - blood plasma). Water acts as the nutrient's highway to cell and tissue, it carries food through digestive system, and carries out waste. Water also keeps the body relatively stable regarding temperature (due to heat capacity), and acts as shock absorbers, lubricators and cleansing agents (tears, synovial fluid, amniotic fluid). Sources include water, juice, fruit, and food.


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15 West Street Natick MA, 01760
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