How long does it take for 75% of phosphocreatine stores to replenish during EPOC?

How long does it take for 75% of phosphocreatine stores to replenish during EPOC?

• A. 30 seconds
• B. 4 minutes
• C. 1 minute
• D. 2-4 minutes

Answer: (C)

During recovery, phosphocreatine stores are rebuilt mainly by ATP produced through aerobic metabolism, so PCr replenishment happens quickly and follows an exponential pattern. The rate has a half-time of about 30 seconds, so after the first 30 seconds roughly half of the depleted PCr is restored. After another 30 seconds, about half of the remaining deficit is replenished, bringing it to around 75% within about one minute. That makes one minute the best estimate for reaching roughly 75% replenishment. Longer times would push past 75% (and much closer to complete replenishment), while 30 seconds would be only about 50% restored.

During recovery, phosphocreatine stores are rebuilt mainly by ATP produced through aerobic metabolism, so PCr replenishment happens quickly and follows an exponential pattern. The rate has a half-time of about 30 seconds, so after the first 30 seconds roughly half of the depleted PCr is restored. After another 30 seconds, about half of the remaining deficit is replenished, bringing it to around 75% within about one minute. That makes one minute the best estimate for reaching roughly 75% replenishment. Longer times would push past 75% (and much closer to complete replenishment), while 30 seconds would be only about 50% restored.