Put Your Heart Into It

There are a few persistent misunderstandings about heart rate training that crop up in the group from time to time, so I'm going to address some of them. This is not the full picture on HR training and isn't a guide to health. If you're going out to train in a way that keeps your heart rate up for any length of time or push it to its limits, it's well worth getting it checked before you do, along with the rest of your body.

In training terms, understanding your heart rate and its implications is a very useful tool. It's only one tool in your kit, just one layer of information, but used wisely it is a good indicator of how hard and smart we're training, and how that training is paying off or might need to change, so it's worth understanding what's going on with your heart and unpacking some of the misunderstandings.

Probably the most common mistake people make when discussing the subject or designing their own programme is to refer to all training that raises your HR as "cardio" or “conditioning” and that feeds the common misapprehension is that those terms mean the same as aerobic, but obviously they don’t. The terms arose in some sports to distinguish between the strength and skill training elements of a training programme and the parts that might do something to improve aerobic capacity, but in themselves they have little meaning. Typically, what's referred to as "cardio" or “conditioning” is mid to high HR zones, often around Lactate Threshold or above it, and most often for durations of 60 mins or less. A number of popular training systems sell the idea that you go as hard as possible a few times a week and that’s it, your “cardio” is sorted. That'll only do so much improve your aerobic ability, particularly if it's the only thing you do. The work for improving your aerobic ability is less intense and takes much longer, so don't be fooled into thinking your endurance will be improved by a few short, hard sessions, no matter how high your HR gets. If that's the only HR training you do, at best you'll see a short term, limited improvement that will plateau quite quickly, limit the level of endurance you can achieve and increase your chances of overtraining and injury. Adding a limited amount of those high intensity sessions to your programme is important, but here's just no substitute for putting in the hours at low intensities to improve your endurance.
If you find you’re using those terms to describe any part of your training, you might want to examine what you’re doing to ensure you’re getting your balance of intensities right for what you’re aiming for and if you advise anyone to "do cardio", you're not really saying anything particularly helpful.

For training purposes, the HR values that particularly interest us are often referred to as "zones", often set out in a in a 5 or 6 zone model and often defined by percentage boundaries, but there's no universally agreed system and those percentage boundaries are really just estimates. If you're going to train by HR I'd suggest you use the increasingly popular method of just 3 zones - up to and at Aerobic Threshold (AeT), above AeT up to Lactate Threshold (LT aka Anaerobic Threshold) and anything above LT/AnT. Scientifically speaking, the breakdown is more detailed, the thresholds are really transition ranges (in truth everything is aerobic and lactate is playing a role long before we can feel its effects) and still the subject of research to more precisely define and understand those points, but in practical terms the vast majority of your HR based training will fit into those three choices, with the zone 1 forming the largest part, zone 2 quite a bit less, and zone 3 a very small portion. If you aim to do particularly high volumes of training or you're training for something other than mountaineering then you might benefit from an expanded model of zones, but for the vast majority of this group and the alpine training we’re interested in, the three-zone scheme is more than adequate for our needs.

There are a few methods for assessing your max HR, AeT and LT and you can see my view on testing them and other aspects of fitness here, along with some suggestions on how to go about it here. It's well worth doing that, you'll quickly start building a picture of what your values are and how to use them which can add a whole new layer of effectiveness to your training. Retest them periodically to make sure you're training in the right way for you. It's also possible to train based on field-observable markers like nose breathing, or the perceived scale of exertion, and achieve good results without knowing the precise numbers. You can also learn the numbers as you go along from those observations.

The 220-age formula is popular as a way of determining HR zones, but it’s far too unreliable for training purposes. It's a statistical tool, for assessing health, not a formula for determining personal max HR. I strongly suggest you don't rely on it. There are other similar formulae reputed to be more accurate, but none are perfect or even particularly widely accepted that I know of and I’d suggest instead you take the tests if you really want accuracy.

Once you have those marks, the most basic and important use of them for training purposes is this - you identify a target HR/zone and work at it for a target duration, distance, total ascent or other measure of volume....and that's it, that's the workout. We can talk about specificity, applicability etc. another time, but the most fundamental aspect of training by HR is just what I've said above and that's how you use it. You can manipulate the pace, slope angle, load or intensity you work at to hit the HR target and get you into zone for the goal duration/volume/ascent etc, but the basic principle doesn’t change. That concept trips some people up, they imagine there's some set value to the pace or intensity which coincides with a particular HR or zone, but there isn't. My AeT and the level of activity I'm capable of at that value will be somewhat different from yours, or anyone else's, we'll all be working at a different pace, intensity or load to achieve the same training result. For example, I head out and run at 5mins/km to achieve my AeT for 1hr. You go out and run at 4.30mins/km at your AeT for the same hour and we have done the same workout at different paces. Take any other measures of pace, ascent or volume and the same applies, it’s really that simple.

In your training between AeT And LT, it’s the same again; I want to improve my LT, so I go and do something like a 30 min run at or close to it, or an interval session where my HR during the working portion is close to my LT or above it.

That small portion of training we do above LT, the hardest work which is sustainable only for a matter of seconds to minutes depending on how far above it you go, is built on the same foundation, you aim to achieve a particular HR range and sustain for the required time or volume. Once you get a long way above the LT you'll be training at an intensity that’s not sustainable for more than a matter of seconds. Typically that'll be hill sprints, circuit training, any kind of HIIT and similar. Observed HR isn’t a useful guide in this kind of workout, you won't see the HR change during the exercise. Typically you'll go as hard as you can for the exercise and judge the effort by how it feels at the time/how long you can sustain it, then look at the HR afterwards.

You can of course train by other marks, such as heading out to do a 30k cycle in 60 mins (which doesn't happen to coincide with your AeT, LT etc), but now you're not training by HR anymore. You can observe and record your HR during and after and learn a lot from that, but the principal still stands, if you go by pace/distance/volume etc, you're not training by HR. There's nothing inherently wrong with that and if you're training for a race of any kind, or perhaps a summit day that has a precise height and pace requirement then training by pace could form an important part of your programme, but you still need to understand that you've stopped training *by* HR once you do that. The feedback from looking at what your heart did during a session like that will still be useful though, so record it if you can.

Local muscular endurance training is outside this matrix as the aim is to do a set volume at a pace that challenges the endurance of a particular group of muscles, so your HR shouldn't be the target or a limiting factor, beyond making sure you don't stray into such high zones that you can't sustain the workout long enough to challenge the muscles you're targeting. Typically you'll do something like 60 mins or more of box steps with x% of bodyweight added at a pace that you can sustain at AeT or a little above it, which should leave you with tired legs. Broadly speaking, the same goes for weight training, that's about the weight/volume you shift per lift/set/workout, not a target HR.

So.....taking all that together, a week of training by the 80/20 or polarised model look might look like this for the parts of your training where you’re training by HR;
(illustrative figures only)

3x90 mins (or a similar breakdown such as 2x1hr and 1x2.5hr) of aerobic training, ie at or near AeT - 270 mins, about 80% of weekly total

1x45 mins at or close to LT - roughly 12.5% of weekly total

1x30 mins of intervals (or similar) above LT - about 7.5% of weekly total

Obviously the volume of all of those things can be scaled up as you get fitter (best not to increase by more than 10% per week) or you or it will change for specific periods depending on upcoming targets and immediate needs, like maybe dropping the higher intensity sessions and adding more muscular endurance training in the months before a big mountain, or adding two of the sessions together to do very long workouts on the hills or a stairmaster. Your lifestyle and available time may demand that you structure it in a particular way, but the distribution shouldn’t change too far from that breakdown for the majority of your training. The above example would give you 5h 45m of HR based training, then if you add training such as going to the climbing wall and weight training you'll end up at about 12-14 hours per week. That's about the average training load in this group and it’s what's probably sustainable for most of us for the majority of the year, again increasing at appropriate times.

As I said, this is not a full guide to HR based training, or training in general, and the volumes are illustrative only, but hopefully it's a starting point for anyone who didn't have a clear picture to start with or laboured under some of the more common misapprehensions about HR training.

Hope you're all training and climbing well,