Observing and measuring performance
First we observe: watch the athlete and note what happens. Then we measure, so we can compare today with last month.
- Time: stopwatch or timing gates (light beams that start and stop a clock).
- Speed = distance ÷ time, in metres per second (m/s). Multiply by 3.6 to get km/h.
- Split times: the time for each part of a race. They show where an athlete is slow.
- Quantitative data are numbers (12.1 s). Qualitative data are descriptions ("knees too low").
A good test is valid (it measures what it should) and reliable (you get the same result when you repeat it).
Sensors, apps and wearables
A wearable is a small device worn on the body: a chest strap, smart watch or GPS vest. It records heart rate, distance, speed, steps and sleep.
- Maximum heart rate ≈ 220 − age (beats per minute, bpm).
- Training zones: 60–70% for easy endurance, 70–80% to build stamina, 80–90% and above for hard intervals.
- GPS shows total distance and sprint count in team sports.
- Force plates and motion capture measure jump force and joint angles (this is biomechanics: the physics of movement).
- Apps show slow-motion video, draw angles on the screen and store results over time.
Video, notational analysis and strategy
Notational analysis means recording every event in a match with a tally: passes, shots, tackles, errors, where on the field they happen.
The coach then asks questions: Who is our key passer? Where do we lose the ball? Which side does the opponent attack from? The answers become a strategy (the long-term game plan) and tactics (actions in the match, such as marking one player).
Using data well
Data need context. Five passes in a calm minute mean less than five passes under pressure. Combine numbers with what you saw.
Equipment innovation and how sports evolve
Sport changes when equipment, materials or rules change.
- Materials: wood → aluminium → carbon fibre rackets, bats and bikes: lighter and stiffer.
- Shoes: foam and carbon plates return more energy to the runner.
- Surfaces: synthetic tracks and artificial turf give a fast, even surface.
- Safety: helmets, padding and concussion tests protect players.
Governing bodies set limits when a product gives an unfair edge (for example full-body polyurethane swimsuits were banned in 2010). The question is always: does it help everyone, or only those who can pay?
Officiating technology: fair decisions
Fast cameras and computers help officials: ball tracking in tennis and cricket, goal-line technology and video review in football, photo finish in athletics, electronic touch pads in swimming.
For: fewer wrong decisions, fairer results, replays for fans. Against: cost (small clubs cannot pay), slower games, arguments about tiny margins.
Careers in sport and health
Sports science opens many jobs:
- Coach / PE teacher: plans training and teaches skills.
- Performance analyst: studies video and data.
- Physiotherapist: prevents and treats injuries.
- Sports scientist / strength and conditioning coach: tests fitness and plans loads.
- Nutritionist, sports psychologist, referee, event manager.
Pathways: school PE and science → a diploma or degree in sports science, physiotherapy or PE → coaching badges and practical experience. Skills: communication, teamwork, data handling, first aid and knowledge of how the body works.
Try it: measure your own sprint
Mark 0 m, 10 m and 20 m with stones. A friend starts a phone stopwatch on "Go" and stops it at 20 m. Run three times and take the best. Speed = 20 ÷ time. Then use the free-play step in the 3D to check your answer.
Key formulas and definitions
- Speed (m/s) = distance (m) ÷ time (s)
- km/h = m/s × 3.6
- Split time = time at end of section − time at start of section
- Maximum heart rate ≈ 220 − age (bpm)
- Target heart rate = percentage × maximum heart rate
Worked examples
1. A runner covers 100 m in 12.5 s. Find the average speed in m/s and km/h.
Speed = 100 ÷ 12.5 = 8 m/s. In km/h: 8 × 3.6 = 28.8 km/h.
2. Timing gates show 9.6 s at 80 m and 11.7 s at 100 m. Find the speed over the last 20 m.
Split time = 11.7 − 9.6 = 2.1 s. Speed = 20 ÷ 2.1 ≈ 9.5 m/s.
3. A 15-year-old wants to train at 70–80% of maximum heart rate. What range should the watch show?
Max HR = 220 − 15 = 205 bpm. 70% = 0.7 × 205 = 143.5 ≈ 144 bpm. 80% = 0.8 × 205 = 164 bpm. Range: about 144–164 bpm.
4. A tally shows Team A made 120 passes and completed 96. What is the pass completion rate?
Rate = completed ÷ attempted × 100 = 96 ÷ 120 × 100 = 80%.
Common mistakes
- Using total time instead of the split time when finding speed over one section.
- Forgetting to convert: m/s × 3.6 = km/h (not ÷ 3.6).
- Thinking more data is always better. Data without context can mislead.
- Believing technology is always fair. Costly kit can help only rich teams; rules are needed.