𝐘𝐨𝐮 𝐟𝐚𝐭𝐢𝐠𝐮𝐞 𝐟𝐚𝐬𝐭𝐞𝐫 𝐚𝐭 𝐡𝐢𝐠𝐡𝐞𝐫 𝐢𝐧𝐭𝐞𝐧𝐬𝐢𝐭𝐢𝐞𝐬
Intuitively, this is obvious.
If you sprint, you can’t sprint for a long time, and the faster you sprint, the shorter the time you can keep sprinting.
What’s not obvious is that there is a mathematical relationship between your intensity (your effort) and how long you can hold it.
𝐓𝐡𝐞 𝐫𝐞𝐬𝐞𝐚𝐫𝐜𝐡
Monod and Scherrer’s research into single muscle groups showed that the fast component of fatigue follows a hyperbolic curve.
This research identified the bottom of the curve (the asymptote) as ‘an exercise intensity that could be sustained for a very long time’, naming it Critical Power (CP).
The research also identified that the curve’s hyperbolic shape makes it ‘possible to define the maximum amount of work that can be performed in a given time, as well as the conditions of work performed without fatigue.’
They called this maximum amount of work W’. Anaerobic Work Capacity (AWC) and Reserve Work Capacity (RWC) are other names for W’; Functional Reserve Capacity (FRC) describes a similar concept with a different calculation method (but still hyperbolic).
Further research by Hill extended and validated these concepts for whole-body exercise, noting that ‘for a very long time’ was usually 30 to 60 minutes of exercise at CP.
𝐖𝐡𝐲 𝐢𝐬 𝐭𝐡𝐢𝐬 𝐮𝐬𝐞𝐟𝐮𝐥?
Knowing the maximum amount of work you can perform and the event distance, you can calculate a race power target for a shorter event (e.g. a 5k), where the fast component dominates.
𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?
For more information on the research, please see:
🔹 Monod, H. & Scherrer, J., (2007) The Work Capacity of a Synergic Muscle Group
🔹 Hill, D., (2012) The Critical Power Concept
You fatigue faster at higher intensities
