Physical Education: Sports Science: How the Body Performs
Exploring energy systems, movement, fitness, and performance
Physical Education: Sports Science: How the Body Performs
Exploring energy systems, movement, fitness, and performance
Physical Education - Grade 9-12
- 1
A sprinter explodes out of the blocks and runs a 100-meter dash in about 12 seconds. Which energy system provides most of the energy at the start of the race, and why?
Think about which system supports maximum effort for only a few seconds.
The ATP-PC system provides most of the energy at the start of the race because it can produce energy very quickly for short, powerful efforts without needing oxygen. - 2
During a 30-minute steady jog, which energy system is used the most, and what role does oxygen play?
The aerobic energy system is used the most during a 30-minute steady jog. Oxygen helps the body break down carbohydrates and fats to produce energy for a longer period of time. - 3
A basketball player performs repeated fast breaks throughout a game. Explain why both anaerobic and aerobic fitness are important for this athlete.
Consider both the sprint and the recovery period after the sprint.
Anaerobic fitness is important because fast breaks require short bursts of speed and power. Aerobic fitness is also important because it helps the athlete recover between bursts and maintain performance throughout the game. - 4
A student has a resting heart rate of 68 beats per minute and a maximum heart rate of 195 beats per minute. Calculate the student's heart rate reserve.
Heart rate reserve equals maximum heart rate minus resting heart rate.
The student's heart rate reserve is 127 beats per minute because 195 minus 68 equals 127. - 5
Using the student's heart rate reserve of 127 beats per minute and resting heart rate of 68 beats per minute, calculate the target heart rate at 70 percent intensity using the Karvonen formula.
The target heart rate is about 157 beats per minute. Using the Karvonen formula, 127 times 0.70 equals 88.9, and 88.9 plus 68 equals 156.9. - 6
Look at a squat movement. Identify two major joints involved and describe the main movement at each joint during the lowering phase.
Focus on what happens as the body moves downward.
During the lowering phase of a squat, the knees flex as they bend and the hips flex as the thighs move closer to the torso. The ankles also dorsiflex as the knees move forward over the feet. - 7
A volleyball player jumps to block a shot. Explain how force production and the stretch-shortening cycle help improve jump height.
Force production helps the athlete push strongly against the ground. The stretch-shortening cycle helps because a quick dip before jumping stretches the muscles and tendons, allowing them to recoil and produce a more powerful upward movement. - 8
Define muscular endurance and give one sport-specific example of why it matters.
Endurance is about repeating effort, not just lifting the heaviest weight once.
Muscular endurance is the ability of a muscle or muscle group to perform repeated contractions over time. It matters in rowing because the arms, back, and legs must keep producing force repeatedly throughout a race. - 9
A soccer player wants to improve acceleration over the first 10 meters. Name two training methods that could help and explain why they are useful.
Sprint starts can help because they practice explosive first steps. Strength training for the legs can also help because stronger muscles can apply more force to the ground during acceleration. - 10
Explain the difference between reaction time and movement time using an example from a sport.
One happens before the body begins moving, and the other happens during the movement.
Reaction time is the time it takes to respond to a signal, such as a tennis player recognizing where a serve is going. Movement time is the time it takes to complete the physical action, such as moving the racket to hit the ball. - 11
A runner's stride becomes shorter and less controlled near the end of a race. Explain how fatigue can affect biomechanics and performance.
Fatigue can reduce muscle force, coordination, and balance. This may cause shorter strides, less efficient running form, slower speed, and a greater risk of injury. - 12
Describe how the respiratory system and circulatory system work together during intense exercise.
Think about breathing, blood flow, oxygen delivery, and waste removal.
During intense exercise, the respiratory system brings more oxygen into the lungs and removes carbon dioxide. The circulatory system pumps oxygen-rich blood to working muscles and carries carbon dioxide and other waste products away. - 13
A coach schedules hard sprint workouts every day for two weeks with no rest days. Explain why this plan may reduce performance instead of improving it.
This plan may reduce performance because the body needs recovery time to repair tissues, restore energy stores, and adapt to training. Without enough recovery, the athlete may become overly fatigued and increase the risk of injury. - 14
Explain the principle of specificity and give an example for a swimmer training for a 100-meter freestyle race.
Training should prepare the athlete for the exact demands of the event.
The principle of specificity means training should match the movements, energy demands, and skills of the sport or event. A swimmer training for a 100-meter freestyle should practice fast freestyle intervals, starts, turns, and race-paced efforts. - 15
An athlete drinks little water during a hot practice and begins to feel dizzy and weak. Explain how dehydration can affect body performance and safety.
Dehydration can reduce blood volume, increase heart strain, impair temperature regulation, and decrease muscle performance. It can also raise the risk of heat illness, so the athlete should stop, cool down, and rehydrate safely.