Strength and Flexibility

Introduction

Strength and flexibility are two important parts of physical fitness. Strength is the ability of your muscles to produce force. Flexibility is the ability of a joint and the muscles around it to move through a useful range of motion. Together, they help you move with control in sport, everyday life, dance, games, and physical education.

For learners in Grades 7–8, the main goal is not to lift the heaviest weight or perform the deepest stretch. Your goal is to learn safe movement, build control, notice how your body responds, and make gradual progress. People develop at different rates during adolescence, so comparison with classmates is less useful than comparing your own technique and progress over time.

The World Health Organization recommends that children and adolescents aged 5–17 average at least 60 minutes of moderate-to-vigorous physical activity each day across the week. Vigorous activities and activities that strengthen muscles and bones should be included at least three days each week. A balanced school fitness program can include running, jumping, games, bodyweight exercises, sport, and movement challenges.

Safety comes first. Use a clear space, wear suitable footwear when needed, follow your teacher's instructions, and choose a version of each exercise that you can control. Stop an exercise if you feel sharp or sudden pain, dizziness, or unusual shortness of breath, and tell a responsible adult. If you have an injury or health condition, use the adaptations given by your teacher, coach, physiotherapist, or other qualified health professional.

Understanding Strength

What Is Muscular Strength?

Muscles create force by contracting. You use muscular strength when you push open a heavy door, carry a school bag, climb stairs, jump, hold a plank, or change direction in a game. Strength is related to, but different from, muscular endurance. Strength focuses on how much force you can produce, while muscular endurance focuses on how long or how many times you can repeat an effort with good control.

Young people can develop strength through supervised, age-appropriate resistance training. Resistance can come from your own body mass, gravity, resistance bands, light external loads, or a partner activity designed by a teacher. Good technique and gradual progression matter more than using heavy resistance.

A plank is an example of an isometric strength exercise. In an isometric action, muscles create tension while the body position is held mostly still. Squats and lunges are examples of dynamic strength exercises because joints move while muscles produce force.

Basic Movement Patterns

Many strength activities can be grouped into movement patterns. Learning these patterns helps you transfer good technique from one exercise to another.

Squatting: Bend at the hips, knees, and ankles while keeping your body controlled, then stand tall again.
Lunging: Step or split your stance, lower under control, and push through the floor to return.
Pushing: Push your body or an object away while keeping your shoulders and trunk controlled.
Pulling: Pull your body or an object toward you using your back and arm muscles.
Bracing: Create trunk tension to keep your spine and pelvis steady while you hold or move.

Datei:Squat - exercise demonstration video.webm

Repetitions, Sets, Resistance, and Rest

A repetition is one complete performance of an exercise. A set is a group of repetitions performed before resting. Resistance is the force your muscles work against. Rest gives your muscles and nervous system time to recover before the next effort.

In school strength work, quality matters more than racing. Move through a comfortable range, keep a stable position, breathe normally, and stop the set when your technique starts to break down. Your teacher may change repetitions, time, resistance, or rest so that the activity matches your experience and the lesson goal.

A useful principle is progressive overload: training becomes slightly more challenging over time as your body adapts. Progress can mean better technique, a larger controlled range of motion, one or two extra repetitions, a slightly longer hold, a harder exercise variation, or a small increase in resistance. Progress should be gradual rather than sudden.

Understanding Flexibility

Flexibility and Range of Motion

Flexibility describes how freely a joint can move through a useful range of motion. Your muscles, tendons, joint structure, activity level, temperature, and individual anatomy can all influence that range. Flexibility is specific to a joint and movement, so a person can be flexible in one area and less flexible in another.

Flexibility is not a contest. Forcing a stretch farther than you can control does not automatically make it better. A safe stretch should feel like gentle tension, not sharp pain.

Dynamic and Static Stretching

Dynamic stretching uses controlled movement to take joints through an active range of motion. Examples include arm circles, leg swings, walking lunges, and controlled trunk rotations. Dynamic movements are useful in a warm-up because they raise body temperature and prepare you for movements similar to the activity that follows.

Static stretching means moving into a stretch position and holding it without bouncing. Static stretching is often used after activity or in a separate flexibility session when muscles are warm. A gentle static stretch should be steady and controlled.

Flexibility and Mobility Are Related but Different

Flexibility is the available range of motion around a joint. Mobility is your ability to use a range of motion actively and with control. For example, you may be able to lift your leg high when someone supports it, but active mobility asks whether you can lift and control it yourself.

Strength and flexibility can support each other. Strength through a controlled range can help you use your flexibility safely, while appropriate flexibility can make it easier to reach useful positions in sport and daily movement.

Warm-Up, Training, and Cool-Down

Why Warm Up?

A warm-up prepares your body and attention for more demanding movement. Start with light whole-body activity, then add controlled dynamic movements, and finally rehearse skills similar to the lesson or sport. For example, before a game that includes sprinting and jumping, you might walk or jog, perform dynamic leg movements, and then practise short accelerations and small jumps.

A warm-up should make you feel ready, not exhausted. Static stretching is usually more suitable when muscles are warm rather than as the main activity before explosive running or jumping.

Building a Balanced Session

A simple class session can follow this sequence:

Prepare: Check the space, equipment, and your own readiness.
Warm up: Use light movement and dynamic mobility.
Strength work: Practise a small number of exercises with controlled technique.
Apply: Use strength and mobility in a game, skill, circuit, or movement challenge.
Cool down: Gradually lower the intensity and use comfortable static stretches if appropriate.
Reflect: Record what felt controlled, what was difficult, and what you will change next time.

Planning Progress with FITT

The FITT principle can help you describe an exercise plan.

Frequency means how often you train. Intensity means how challenging the work is. Time means how long the activity, set, or session lasts. Type means the kind of activity you choose.

For strength, you can adjust intensity by changing the exercise variation, resistance, speed, range of motion, or work-to-rest pattern. For flexibility, you can adjust the type of stretch, the number of controlled repetitions, or how long a comfortable static position is held. Only change one or two factors at a time so you can judge how your body responds.

Technique and Self-Monitoring

Good technique is a skill. It improves through attention, feedback, and repetition. Use these checkpoints:

Keep your movement controlled rather than rushed.
Use a range of motion that you can manage without pain.
Breathe steadily and avoid unnecessary straining.
Keep joints aligned for the exercise you are performing.
Ask for feedback when you are unsure.
Leave enough recovery so that the next set can also be performed well.

You can monitor effort with simple words such as easy, moderate, challenging, and very challenging. A school exercise should match the lesson goal and your current ability. You do not need to copy another person's resistance, depth, speed, or range of motion.

Connections to Sport and Everyday Life

Strength and flexibility appear in many activities. A basketball player uses leg strength to jump and trunk control to land. A swimmer needs shoulder mobility and strength to move the arms efficiently. A dancer combines active flexibility with strength to control positions. A cyclist uses leg strength repeatedly and benefits from comfortable movement at the hips and ankles. Carrying groceries, lifting a school bag, sitting and standing, and moving furniture also involve strength and mobility.

Think of fitness as a set of tools. Different activities need different combinations of strength, power, endurance, balance, coordination, speed, and flexibility. Your training should match what you want to do.

Interactive Tasks

Quiz: Test Your Knowledge

What does muscular strength describe? (The ability of muscles to produce force) (!The ability to memorize movement names) (!The speed of the heart at rest) (!The length of a warm up period)

What is flexibility? (The ability of a joint to move through a useful range) (!The ability to lift the heaviest possible load) (!The number of steps taken in a day) (!The speed of a sprint)

Which activity is an isometric strength exercise? (Holding a plank) (!Jogging across a field) (!Swinging the arms in circles) (!Walking slowly after exercise)

Which activity is most suitable for a dynamic warm-up? (Controlled walking lunges) (!A long motionless stretch) (!Sitting still on a bench) (!Testing the heaviest possible lift)

What is one repetition? (One complete performance of an exercise) (!A group of several exercises) (!A full week of training) (!A period of sleep)

What does progressive overload mean? (Gradually increasing the training challenge) (!Changing every exercise at every session) (!Training through sharp pain) (!Always using maximum resistance)

What does the F in FITT stand for? (Frequency) (!Flexibility) (!Force) (!Fitness)

Which statement best describes safe stretching? (Use gentle controlled tension without sharp pain) (!Bounce quickly to reach farther) (!Copy the most flexible person in class) (!Hold your breath during every stretch)

Why is rest useful between strength sets? (It helps you recover for the next effort) (!It permanently reduces flexibility) (!It makes technique less important) (!It replaces the need for a warm up)

Which statement best describes mobility? (The ability to use a range of motion with control) (!The maximum number of push ups in one minute) (!The amount of resistance on a machine) (!The distance covered in a sprint)

Memory Game

Strength	Ability of muscles to produce force
Flexibility	Available range of motion at a joint
Repetition	One complete performance of an exercise
Set	Group of repetitions before a rest
Dynamic stretch	Controlled movement through an active range
Static stretch	Stretch position held without bouncing
Mobility	Active control through a range of motion

Drag and Drop

Match the correct terms.	Topic
Frequency	How often you train
Intensity	How challenging the work is
Time	How long the activity lasts
Type	The kind of activity you choose
Recovery	Time that helps you prepare for the next effort

Match each FITT idea and recovery concept with its meaning.

Crossword Puzzle

Strength	What fitness quality means the ability of muscles to produce force?
Flexibility	What quality describes useful range of motion around a joint?
Warmup	What preparation phase comes before harder exercise?
Plank	What core exercise is commonly held without much joint movement?
Lunge	What exercise uses a split stance and controlled lowering?
Recovery	What process helps you prepare for another effort after work?

LearningApps

Cloze Text

Open-Ended Tasks

Easy

Movement Vocabulary: Create a one-page illustrated glossary for strength, flexibility, repetition, set, mobility, and recovery using your own examples.
Technique Observation: Watch a classmate perform a teacher-selected bodyweight exercise and write two specific pieces of positive technique feedback.
Warm-Up Design: Create a five-movement dynamic warm-up for a sport or PE activity and explain what each movement prepares.
Flexibility Journal: Record how two comfortable stretches feel before and after a normal PE lesson and describe any change without forcing the range.

Standard

Strength Circuit: Design a short bodyweight circuit with at least four movement patterns and include clear technique cues and rest periods.
Video Analysis: Record a short teacher-approved exercise demonstration, review it in slow motion, and identify one strength and one control feature to improve.
Sport Movement Interview: Interview a coach, athlete, dancer, or active family member about where strength and flexibility matter in their activity, then summarize the answers.
FITT Plan: Create a one-week class-friendly plan that uses the FITT principle and includes both strength and flexibility work with recovery.

Advanced

Movement Experiment: Compare how a dynamic warm-up and a quiet rest period affect your readiness for a simple teacher-approved movement task, then explain the limits of your comparison.
Progression Project: Create three safe levels of difficulty for one bodyweight exercise and explain the rule for moving from one level to the next.
Fitness Myth Investigation: Research one common claim about stretching or youth strength training using at least two reliable sources and present which parts are supported, uncertain, or misleading.
Inclusive PE Design: Redesign a strength-and-flexibility station so that learners with different movement abilities can participate safely and meaningfully, then explain your adaptations.

Learning Assessment

Technique Reasoning: Explain why a learner who can complete many fast repetitions with poor control may need a different progression than a learner who completes fewer repetitions with strong technique.
Warm-Up Transfer: Design a warm-up for a chosen sport and justify how each movement prepares the joints, muscles, and skills used later.
Program Comparison: Compare two fictional weekly plans and decide which one shows better balance between challenge, recovery, strength, and flexibility, giving evidence for your decision.
Adaptation Challenge: Choose one exercise and show how you would make it easier and harder without changing its main movement pattern.
Flexibility Decision: Given a lesson that includes sprinting and jumping, decide when you would use dynamic and static stretching and explain your reasoning.
Personal Progress Evidence: Use a short training log to identify one sign of progress that is not simply doing more repetitions, and explain why it matters.

Evidence of Learning

Knowledge: You can explain strength, flexibility, mobility, repetitions, sets, resistance, recovery, dynamic stretching, static stretching, progressive overload, and the FITT principle in your own words.

Skills: You can perform teacher-selected strength and flexibility activities with controlled technique, choose an appropriate range of motion, use feedback, and adapt an exercise to your current level.

Products: Useful evidence can include a warm-up plan, training log, exercise diagram, short demonstration video, interview summary, research poster, or FITT-based program.

Transfer: You can explain how strength and flexibility support movement in a sport, dance, outdoor activity, job task, or everyday situation and can select suitable training ideas for a new context.

OERs on the Topic

For further reliable reading, explore World Health Organization guidance on physical activity, NHS guidance on strength and flexibility, and American College of Sports Medicine information on youth resistance training.

Linked Learning Areas

Strength and Flexibility

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