這是個很好的問題。我也是最近才開始看這個LTHR。這個Garmin的論壇也有討論這個問題

https://forums.garmin.com/outdoor-recreation/outdoor-recreation-archive/f/fenix-5-series/143243/heart-rate-zones-which-should-i-use---resting-hr-or-lactate-threshold

特別是這個人說的，有四個選擇，還提到了heart rate reserve

1a. HR zones based on 220-age HR Max. This formula is OK for the population average as a whole, but is a rubbish predictor for any one individual.
1b. HR zones based on YOUR known and tested HR Max. This is significantly better than 1a.
2. HR zones based on HRH (Heart Rate Reserve) - which is HRMax - RHR.(Assuming a known HRMax rather than a formula based HRMax). The advantage of this method is that it uses the actual operating range of YOUR heart, rather than some implied assumptions about where the bottom end of this range might be. Trained runners will tend to have low RHR's, so Z1 and Z2 in particular may be slightly lower on this basis than the other formulae.
3. LTHR. This introduces a new performance-based HR data point. When combined with autodetect of LTHR with a chest strap, your zones will automatically change based on the effectiveness of your training. This data point is also more relevant for race-pacing, or training at race pace.

All of these methods are going to tend to converge towards your maximum, or at zones 4 and 5. But for those with a low RHR, the HRR method may be more accurate for defining zones 1 and 2.

However, there is in fact a 4th option. In Garmin Connect, you can change the default percentages that define each zone. So you could use %LTHR as the method, but then slightly tweak the percentages to for Z1 and Z2 so that they reflect the equivalent heart rates for these zones using the HRR method.

有人推薦了這個計算器，我覺得似乎接近我現在的心率區間的最低的三個zone。但是第四個和五偏高。。https://theathleteblog.com/heart-rate-zone-calculator/

這個考慮了當天的resting hr 而且給年齡的權重與220-age的算法又不同。還有用手表和用心率帶又不同。

還在摸索中。