Scientifically Explaining My 3000m Run. Critical Power, Anaerobic Work Capacity and Specificity.

Updated: Oct 17, 2021

9:18:07 min, 3000m, 3:06min/km (4:83min/mile).

Going into the race, my goal was to run under 9 minutes. It was an ambitious goal, to say the least. Not only was I amidst training for the 2021 Tarawera 102km Ultramarathon, but my previous 3000m performance was 9:45:87 (3:15min/km).


I prepared by polarising (long slow | short fast) my training and doing one specific track session each week for the four weeks leading into the race.


  1. 3000m time trial (9:47)

  2. 1000m + 10x 200m | 1:30min rest

  3. 3000m race (9:45)

  4. 1600m + 5x 300m | 1:30min rest

  5. 2000m + 3x 400m | 1:30min rest

  6. Race - 9:18

(Buy this training plan for $19 for Pace or Power)


My plan was to target my biggest weakness; my ability to tolerate high lactic acid concentrations. I knew I could run fast, I knew I was fit, but I found out during my initial TT that my ability to tolerate lactate was not great. I like to differentiate between lactate buffering capacity (tempo/threshold) and lactate tolerance. In metric terms, we can use the critical power model to get more insight.

Your critical power is your theoretical aerobic threshold (red line). It is calculated by plotting your recent best performances against time. The result is a power duration curve (Figure 1 - blue line).

The area under the curve is your anaerobic work capacity or W prime (W’). W’ relates to the amount of energy you have available above your threshold. It explains why can’t sprint forever. Read more here.

I have plotted my 3000m race (purple line) against my previous 90-day PDC to explain why I slowed so drastically during my race.

400m race splits