Excercise zones: Aerobic, anaerobic and lactate threshold

[Norse]

Spinoff from this thread which I didn’t want to derail.

Since I’m trying to resurrect my currently dormant excercise routines, I’ve become more aware of heart rates and the aerobic/anaerobic balance. And to be true to my status as a middle-aged male suffering from a moderate midlife crisis, I’ve gone and bought myself a new heart rate monitor.

The problem is that I just can’t agree with what I’ve been reading about the issue. Example. I’m in my late forties, so according to most charts (and also according to the functions in my HRM) my maximum heart rate should be about 170-175 bpm, and my lactate threshold should be around 140 bpm. Now, this just has to be wrong. First claim for fail: I have on several occasions, when I’ve been exerting myself during excercise, reached heart rates between 185 and 190. >185 is quite a bit more than 175. Second claim for fail: My aerobic zone should be somewhere in the region from roughly 120 to 140 bpm. A few years ago I completed a 9k MTB race in between 4.5 and 5 hours, with an average HR of 160 bpm and a maximum HR of 187. OK, I know that I was about five years younger then and that I was in much better shape, but still? According to the charts, this is well into the “Maximum effort” zone. For almost five friggin’ hours? No way. Even now, in the relatively poor shape I currently am, I don’t feel fully warmed up before my HR is above 130. And I do - fairly consistently - complete spinning passes of 45-60 minutes at an average HR of 155-160. “Maximum effort” for three quarters of an hour? Hard to believe. And even now, 140 feels fairly comfortable for the “active pauses” between the high-effort intervals when I’m doing intervals.

I’ve become rather convinced that the charts I’ve seen online are way too conservative and don’t take into consideration people who have been excercising regularly before, even if one’s current condition is rather mediocre. But am I right? Or am I really overexerting myself so badly that the available information seems to indicate?

Also, I’ve seen different definitions of the zones. The most simplistic is of course the approach that the zone is given by a percentage of your max HR. However, I have occasionally seen definitions which also take into account the resting HR. Type: the zones are given as resting HR + fraction of difference between resting and max HR. This seems like a better definition to me, but frankly, not having a Master’s in sports medicine I can’t tell if it is a good idea.

So, what can the teeming masses tell me about HR zones and lactate threshold that can shed some light on this apparent lack of consistency between what I read and what I experience?

[running_coach]

Lactate threshold: Roughly 83-87% of max. HR though that varies by individual. (Frank Shorter was reported to have a LT at 92%) Race pace for one hour.

Max. heart rate varies greatly. All the charts and formulas are intended for sedentary persons just starting an exercise routine.

These become increasingly inaccurate with older athletes who have maintained fitness.

I’m almost 52 and my max. HR is still 189 against a predicted 168.(220-age)

Determine your max. HR and lactate threshold and go from there.

[Norse]

@runner pat

Lactate threshold: Roughly 83-87% of max. HR though that varies by individual.

Thanks.

@runner pat

Max. heart rate varies greatly. All the charts and formulas are intended for sedentary persons just starting an exercise routine.

These become increasingly inaccurate with older athletes who have maintained fitness.

As I suspected, then. Good to know. Even if I qualify as neither an older athlete nor to have maintained fitness :o

@runner pat

Determine your max. HR and lactate threshold and go from there.

Got it. I’ve got a fairly decent idea about how I might try to determine max HR (good warmup for at least 20 minutes, then gradually increasing to max intensity, and then going further to eleven and perhaps even twelve). But can I determine or estimate my lactate threshold without equipment more advanced than a low-end HR monitor?

[running_coach]

Self testing for max HR. These can be brutal. It might help to have some friends take turns pacing you to get an accurate reading.

Warm up.
Run 800 meters near all out. (9.5 on a ten scale.) Jog one minute then run 800 all out.

Or run a 2 mile or 5k race and go all out for the last 800.

If you have a recent all out race, this calculator will give paces for all types of running.

You can increase your LT by doing regular tempo runs; 20-25 minutes at LT pace.

[DSeid]

Lots of detail available in this American College of Sports Medicine Position Statement.

Maximum heart rate (HRR) and maximum V˙ O2 reserve (V˙ O2R) are calculated from the difference between resting and maximum heart rate and resting and maximum V˙ O2, respectively. To estimate training intensity, a percentage of this value is added to the resting heart rate and/or resting V˙ O2 and is expressed as a percentage of HRR … or V˙O2R

For most untrained individuals, the LT occurs between 40% and 60% of V˙O2max … The LT can be increased independently of V˙O2max and is correlated strongly with endurance capacity (154,245). The LT can be improved rapidly in response to training (10–20%) and appears to be increased by both moderate- and high-intensity exercise training, as well as by both continuous and intermittent exercise (154,202). Perceived exertion at the LT does not change with endurance training despite the fact that the LT occurs at a higher power output, and absolute and relative V˙ O2max. Thus, RPE appears more closely linked with blood lactate than %V˙ O2max after, training (60).

The reduction in V˙O2max that occurs with aging has varied widely in the literature, ranging from 0% to 34% per decade (33,66,107, 130,131,174,211). After 25–30 yr of age, sedentary adults generally experience a 9 – 1 5% reduction in V˙O2max per decade. Although this decline may be attenuated in endurance-trained athletes to approximately 5% per decade…

So yes, the current definition is to determine your maximum heart rate (HRR) and your resting heart rate (RHR). A rough estimate of HRR can be had by that 220 - age formula, or another one, 208 - (0.7*age), but indeed it may be higher for those who have some fitness and then that number should be used. For you it is at least 190. The percents are then the percent of the range from RHR to HRR. Thus for me, same age as runner pat, with a RHR of mid 40s (call it 46) and a HRR measured about 185 to 190 (call it 186). So calling a heart rate of 158 is 80% of my HRR, and 172 gets up to 90%.

In that context this article that reported how actual elite cross country skiers trained, as an observational study, is interesting. LT (called VT1 in this study) for them was at about 81% of HRR, and anaerobic threshold (the maximal lactate steady state, called VT2 in this study) was at about 91% of HRR. What pattern do they adopt?

About 75% of their training sessions are performed with essentially the entire session below the first ventilatory threshold (≤2.0 mM blood lactate). In 5–10% of training sessions, major portions of the training are performed between VT1 and VT2. The remaining 15–20% of training sessions are performed as interval bouts, with substantial periods of work above VT2. … The training intensity distribution observed in these junior males skiers is very similar to the distribution of training observed in elite rowers (Steinacker, 1993; Steinacker et al., 1998), gold medal winning track cyclists (Schumacker & Mueller, 2002), and international class marathoners (Billat et al., 2001). Because this “75-5-20” distribution of training intensity across the three intensity zones demarcated by VT1 and VT2 emerges from several different studies of highly successful performers in different sports from different countries, we hypothesize that it approximates an optimal intensity distribution for training of high-performance endurance athletes.

Take from that what you will. Personally I don’t use HR so much as how hard I feel I am working (RPE officially). But if I was trying to do what the elites do then I’d spend 20% of my exercise time with a heart rate over 172 (in interval training), 75% under 158, and only 5% in between.