What is the correct anaerobic training target zone?

• A. 60%-70%
• B. 80%-90%
• C. 50%-60%
• D. 70%-80%

Answer: (B)

High-intensity efforts that rely on anaerobic energy systems require pushing heart rate into a very high zone. About 80–90% of maximum heart rate is where the body mainly uses the anaerobic pathways (phosphocreatine and anaerobic glycolysis) rather than oxygen to produce energy. Training at this intensity strongly stresses lactate production and buffering, which builds sprint speed, power, and high‑intensity endurance. Lower ranges (50–60% or 60–70%) stay in the aerobic zone, where energy comes mainly from oxygen, so they don’t effectively develop anaerobic capacity. The 70–80% range is closer to the aerobic–anaerobic boundary and isn’t as focused on maximizing anaerobic adaptations as the higher zone.