Friel's training zones

[rapid524]

I've been reading Friel's book and have a couple of questions. While it might make more sense after I've actually done his prescribed LT test using RPE and heartrate, I still have some questions.

Friel's zone 4 has an RPE of 15 to 16 which is described as hard -94 to 100% of Lactate threshold heart rate. Yet what I have read on this site is that Lactate threshold effort is actually fairly low.

What really makes that confusing is that his zone 5C(his highest at an RPE of 20) lists an LTHR of 106% plus. I would've thought that an RPE of 20 would be closer to Max heart rate (I know that HR is not a good indicator in short efforts). Which means that there is only a 6 to 12% difference between LT heart rate and Max heart rate according to Friel. Or am I misinterpreting his chart?

Any comments?

 

[ric_stern/RST]

Originally posted by rapid524
Friel's zone 4 has an RPE of 15 to 16 which is described as hard -94 to 100% of Lactate threshold heart rate. Yet what I have read on this site is that Lactate threshold effort is actually fairly low.

LT, is a low effort -- that which can (usually) be sustained for quite a few hours. Unfortunately, some coaches use the term erroneously and use it to describe a TT type effort. The effort that Friel refers to would imo be better termed as something else. I use the expression TTpower (and then usually denote the duration, e.g., ~ 1-hr). Andy Coggan uses the expression Functional Threshold. These terms better describe the actual intensity.

Further to this, LT should not ever be described with HR metrics. It's definition is the workload that elicits a change in lactate (usually a 1mmol/L increase over exercise baseline, or 2.5 mmol/L). Even if it refers to an outdated figure (e.g. OBLA - 4mmol/L), it's still the workload that elicits the lactate response.

Wokload is in cycling power output (W), and in running would be velocity (km/hr or m/s). At a given workload, HR can vary due to a variety of factors.

Ric