Q.A subject completes the full 5 minutes of the Harvard Step Test and records a pulse count of 72 beats from 1 to 1.5 minutes after exercise. Compute the Physical Fitness Index, state the fitness category, and explain what would happen to the computed PFI if the tester mistakenly doubled the 30-second pulse count to a per-minute rate.

This is a numerical question with a conceptual follow-up.

The Harvard Step Test measures cardiovascular fitness. The CBSE-prescribed formula uses only the 30-second pulse count taken between 1 and 1.5 minutes after exercise — it is not doubled to a per-minute rate.

Given:

• Duration = 5 minutes = 300 seconds
• Pulse count (30-second) = 72 beats

PFI calculation:

PFI = (300 × 100)/(5.5 × 72) = 30000/396 ≈ 75.76

Rounded to the nearest whole number, the PFI is 76.

Fitness category: Since 76 falls in the range 50–80, the fitness category is Average.

Effect of mistakenly doubling the pulse count: If the tester doubled the 30-second count to a per-minute rate of 144, the denominator becomes 5.5 × 144 = 792, giving:

PFI = 30000/792 ≈ 37.88 …

The Harvard Step Test is a simple, field-based test of cardiorespiratory fitness. It measures how quickly your heart rate recovers after a standardised bout of stepping. A faster recovery (lower pulse count) yields a higher PFI, indicating better fitness. The test is widely used in Indian schools and physical education exams because it requires minimal equipment — just a bench of the correct height and a metronome.

The formula prescribed by the CBSE syllabus is:

Here, the pulse count is the raw 30-second count taken between 1 minute and 1.5 minutes after the exercise ends. It is not doubled to a per-minute rate. The duration for a full test is 300 seconds (5 minutes × 60 seconds).

Now, let's apply this to the given data. The subject completed the full 5 minutes, so duration = 300 seconds. The pulse count recorded in the 30-second window from 1 to 1.5 minutes after exercise is 72 beats.

Substituting into the formula:

1. Numerator: 300 × 100 = 30000
2. Denominator: 5.5 × 72 = 396
3. PFI: 30000/396 ≈ 75.76 …