Which exercise protocol is the most commonly used in exercise ECG testing?

• A. Naughton protocol
• B. Bruce protocol
• C. Balke protocol
• D. Modified Bruce protocol

Answer: (B)

The main concept is having a treadmill test with a standardized, widely applicable workload progression so results are comparable across labs. The Bruce protocol fits this because it provides a simple, well-validated treadmill progression: the workload increases in fixed 3-minute stages by raising both speed and incline. This creates a broad and predictable range of metabolic demands, allowing clear assessment of exercise capacity and reliable interpretation of ECG responses across a wide patient population. Its long history means there is abundant normative data and well-established criteria for abnormal findings, making it the default choice in many exercise ECG laboratories.

Other protocols exist for particular situations—Naughton starts more gently and may be better for people with limited exercise capacity; Balke uses a constant speed with increasing incline and is less commonly used in routine practice; Modified Bruce adapts the Bruce design for older or less fit patients—but they don’t provide the same combination of straightforward progression, broad workload range, and extensive reference data that makes the Bruce protocol the most commonly used in general exercise ECG testing.