Which interval pattern describes the phosphagen pathway training?

• A. 10-30 seconds work; 30-90 seconds rest; repeated 25-30 times
• B. 5-10 seconds work; 15-30 seconds rest; repeated 40 times
• C. 60-120 seconds work; 60-120 seconds rest; repeated 8-12 times
• D. 30-60 seconds work; 60-90 seconds rest; repeated 15 times

Answer: (A)

The phosphagen pathway provides energy for very short, explosive efforts and relies on phosphocreatine stores. Training that targets this system uses short, all-out work intervals in the 10–30 second range and allows enough rest (30–90 seconds) for PC to be rephosphorylated before the next effort. Repeating these bouts 25–30 times keeps the total volume high while staying within the capacity of the phosphagen system, promoting repeated maximal efforts without a heavy shift toward glycolysis or aerobic metabolism. In short, this pattern matches the characteristics of the phosphagen system—brief, intense efforts with recovery that enables multiple repeats.