Calculating Training Intensities

This lesson covers how to calculate and monitor training intensity, a key skill required by the OCR GCSE PE specification (J587). You must be able to calculate maximum heart rate, determine aerobic and anaerobic training zones, and understand how percentage of 1RM is used to set weight training loads. These calculations appear regularly in OCR Paper 1, often as part of data-analysis or application questions.

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Maximum Heart Rate (MHR)

Formula:

Maximum Heart Rate = 220 − age

Examples

Age	Calculation	Maximum Heart Rate
15	220 − 15	205 bpm
25	220 − 25	195 bpm
40	220 − 40	180 bpm

This is an estimate — actual maximum heart rate varies between individuals. However, this formula is the one required by OCR and is the one used in exams.

Exam Tip: Always show your working. If the question gives you a person's age, write out the formula, substitute the age, and calculate the answer. Even if your final number is wrong, you may still earn marks for the correct method.

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Training Zones

Once you know a performer's MHR, you can calculate the heart rate range for different training zones. The two key zones for OCR are:

Aerobic Training Zone (60–80% of MHR)

This zone develops cardiovascular endurance. Training at this intensity uses the aerobic energy system (oxygen is available to produce energy).

Anaerobic Training Zone (80–90% of MHR)

This zone develops anaerobic endurance and speed endurance. Training at this intensity exceeds the body's ability to supply oxygen, so the anaerobic energy system is used.

graph LR
    A["Rest<br>< 50% MHR"] --> B["Fat Burning<br>50-60% MHR"]
    B --> C["Aerobic Zone<br>60-80% MHR"]
    C --> D["Anaerobic Zone<br>80-90% MHR"]
    D --> E["Maximum<br>90-100% MHR"]

    style A fill:#3498db,color:#fff
    style B fill:#2ecc71,color:#fff
    style C fill:#f39c12,color:#fff
    style D fill:#e67e22,color:#fff
    style E fill:#e74c3c,color:#fff

Calculating Training Zone Heart Rates

Example: Calculate the aerobic training zone for a 16-year-old.

1. MHR = 220 − 16 = 204 bpm
2. Lower limit (60%) = 204 × 0.60 = 122 bpm (rounded)
3. Upper limit (80%) = 204 × 0.80 = 163 bpm (rounded)
4. Aerobic training zone = 122–163 bpm

Example: Calculate the anaerobic training zone for a 16-year-old.

1. MHR = 204 bpm (calculated above)
2. Lower limit (80%) = 204 × 0.80 = 163 bpm
3. Upper limit (90%) = 204 × 0.90 = 184 bpm (rounded)
4. Anaerobic training zone = 163–184 bpm

Summary Table for a 16-Year-Old

Training Zone	Percentage of MHR	Heart Rate Range
Aerobic	60–80%	122–163 bpm
Anaerobic	80–90%	163–184 bpm
Maximum	90–100%	184–204 bpm

Exam Tip: If the exam asks you to calculate a training zone and you are given an age, always start by calculating MHR using 220 − age. Then multiply by the percentage as a decimal (e.g., 60% = 0.60). Show every step.

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Monitoring Intensity During Training

Heart rate can be monitored during exercise in several ways:

Method	Description	Advantages	Disadvantages
Heart rate monitor (chest strap + watch)	Electronic device that continuously measures heart rate	Very accurate; real-time feedback	Can be expensive; may be uncomfortable
Pulse check (manual)	Performer counts pulse at the wrist (radial) or neck (carotid) for 15 seconds and multiplies by 4	Free; no equipment needed	Inaccurate if the count is wrong; exercise must pause to take the reading
Fitness tracker / smartwatch	Wrist-worn device with optical heart rate sensor	Convenient; records data over time	Less accurate than chest-strap monitors; can be affected by movement
Rate of Perceived Exertion (RPE)	The performer rates how hard they feel they are working on a scale of 6–20 (Borg scale)	No equipment; can be used anywhere	Subjective — different people perceive effort differently

The Borg RPE Scale

RPE	Perceived Effort	Approximate % MHR
6	No exertion	—
9	Very light	~50%
11	Light	~60%
13	Somewhat hard	~70%
15	Hard	~80%
17	Very hard	~90%
19	Extremely hard	~95%
20	Maximum exertion	100%

A rough conversion is: RPE × 10 ≈ heart rate. For example, an RPE of 15 suggests a heart rate of approximately 150 bpm.

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1RM Percentages for Weight Training

The one-rep max (1RM) is the maximum weight a performer can lift once with correct technique for a given exercise. Percentages of 1RM are used to set training loads.

Calculating a Training Load

Example: A performer has a bench press 1RM of 80 kg. They want to train for muscular endurance at 60% of 1RM.

Training load = 80 × 0.60 = 48 kg

Training Goals and 1RM Percentages

Training Goal	% of 1RM	Reps	Sets
Maximal strength	85–100%	1–5	3–5
Power	70–85% (explosive)	6–10	3–5
Hypertrophy	70–85%	8–12	3–5
Muscular endurance	50–70%	12–20+	2–4

Worked Example: Designing a Weight Training Session

A rugby forward wants to improve maximal strength for scrummaging. Their 1RM for the squat is 120 kg.

Detail	Value
Training goal	Maximal strength
% of 1RM	90%
Training load	120 × 0.90 = 108 kg
Repetitions	3
Sets	4
Rest between sets	4 minutes

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Applying Training Zones to Training Methods

Training Method	Typical Training Zone	Reason
Continuous training	Aerobic zone (60–80% MHR)	Sustained effort at moderate intensity to develop cardiovascular endurance
Fartlek training	Varies — aerobic and anaerobic zones	Pace changes mean heart rate fluctuates between zones
Interval training (aerobic focus)	Aerobic zone (60–80% MHR)	Longer work periods with shorter rest target the aerobic system
Interval training (anaerobic focus)	Anaerobic zone (80–90% MHR)	Shorter, more intense work periods with longer rest target the anaerobic system
HIIT	Anaerobic to maximum (85–100% MHR)	Very short, very intense bursts push heart rate to near-maximum levels
Weight training	Varies	Heart rate depends on the load, reps, and rest periods

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Common Exam Mistakes