Hi Everyone-
In our biathlon training we talk a lot about workout zones. Above are some rough estimates of zones that I have used for a number of years, based primarily on breathing levels and better, the heartrates [HRs] based off of your current Lactate Threshold.

Obviously if you are going to use the more accurate method of zone control with heartrates you need an easy way to determine your present heartrate as you are working out. Most serious athletes use a heartrate monitor. Polar is a good brand. Lasts pretty well. The more inexpensive models give you your current heartrate accurate enough so even the Human Performance Lab at St Cloud State used them during the physiological tests they ran for us.

More expensive models will allow the training zones to be inputted and will keep track of the amount of time in each workout spent in each zone. Nice feature. The most expensive ones allow interface with a computer, graphing the workout etc. I find those to be highly useful for a couple of weeks until you get tired of looking at the graphs. I am sure with  daily coaching at a super high level it is great to do that.

The next problem is that your actual heartrate [HR] at the lactate threshold [normally about 4 mmoles of lactate in the blood] will vary a lot depending on a] the individual b] the level of training c] the type of training and other factors. The type of training question is insidious as too much middle to high intensity training will cause the body to burn carbos more than desirable, which produces more lactate than normal and thus the lactate threshold will be at a lower HR than normal. That is undesirable!  Difficult to ski well and definitely difficult to shoot well with high lactates!!

So in any case, the underlying problem is determining your lactate threshold accurately. The most direct way is a lactate profile –normally running on a treadmill that is periodically sped up, with blood drawn from a finger prick and tested with each stage. This will yield a profile and the appropriate lactate level can be picked off and related to a corresponding HR. The test is normally expensive. It is also really not specific to skiing as you are using only your legs unless you can ski on the treadmill. There are a few of those around in the US.

Another approximate method is to go out and  ski as hard as you can for an hour, and  average out your heartrate. That is specific as to being on skis, but the determination of the avg HR is problematic with hills etc thrown in. Of course the best method is a ski capable treadmill in a lab setting using the blood sampling method. That is accurate!

Another method that is approximate, but specific, is to go out on a very flat trail and ski behind a bike. The biker records the speed and holds the pace steady for say 1/4 mile and gets a HR from the skier at the end. [actually 2 readings near the end—say 0.2 and 0.25 mi for each increment works better]. Then the speed is increase by 1 mph. and this continues to refusal by the skier to go faster. I like then to reverse the course to average out the grades and wind and do it again. Armed with these figures, the coach can look at the curve produced which normally rises in a straight line [aerobic response] up to a point where it then curves over to the right [anaerobic response] . The point of curvature is called the Conconi point and is pretty close to the HR at the lactate threshold. It can be hard to pick out, however. Some curves are pretty gradual in change at the breakpoint.

There are other similar running tests on a track—which are good except they again are using only the legs.

Lacking any of the above, here is a chart from USBA’s log form that works off of the max HR. While I like this for the lower levels, unless as above, the athlete has trained properly and the LT is at a good normal level, the lactates in Level 2, 3 and 4 will be too high for any given HR. So if you have no other information to go by, and your max HR is 210, your level 1 should be between 126 and 151 heartrate. But at the assumed LT, the HR would be at 184. In reality that might be too high for you until you turn your body into a fat burning machine with low intensity training—a lot of low intensity training!! Plus a good diet, good hydration and good sleep every night.

If you have that problem and are using carbos too early in the intensity curve, and you do too much level 2 work using this graph, you actually will be at a much higher lactate level than desirable and will be increasing the problem long term by encouraging the usage of carbos by the body instead of the more desirable fats. Fat burns clean..no lactates.