Hello!
i am wondering about Zone definitions (Transition, Fresh, Grey, Optimal, High Risk). In the fitness chart, they are based on the relative Form/TSB (Form %), while the linked reference defines them based on the absolut TSB: Managing Training Using TSB | Joe Friel (TSB = CLT - ALT)
For me (starting again training after long covid, so very low fitness arround 20), this makes now large difference for the “high risk” zone:
Taking Joe Friels Definition, it is ok to go up to -30 TSB. So for my fitness of 20, i could train now with an ATL up to 50 to avoid the high risk zone.
If i take the definition from the fitness chart, then the high risk zone is defined from -30% if relative Form/TSB. So my relative TSB should be no below -30%. This would mean that i should train now only with maximum ALT of 26 ? (20 + 0.3*20 = 26).
Is there any scientific litereture for this “retlative definition” of these zones? Or where does this come from?
Thanks a lot!
David