Staying in Recommended HR Zones

Q: I’m 57 and have a max heart rate around 170. My heart rate zones are fairly narrow and it is a challenge to stay in a zone and I often ping-pong above and below a zone.

1.How strictly should one stay in recommended zones?

2.What tips can you offer to reach and stay within a recommended zone?


Why is it easier to get my heart rate higher while running than skiing/roller skiing?

Q: I feel my heart rate zones are at least 5 bpm lower skiing?

A: On the question about HR at similar efforts with different methods, my guess would be your body is currently more efficient at running and thus you are able to comfortably maintain a higher HR running than you are skiing. With skiing you may have some technique inefficiencies that are causing your body to react to the mode of training and producing blood chemistry reactions like higher blood lactate production at the lower heart rates using one method of training over the other.

Using Karvonen Formula to Estimate Max Heart Rate and Training Zones

The Karvonen method is an estimate of your max heart rate and training zones.  However, it is an estimate that can still be quite aways off, especially compared to the gold standard of physiological testing in a lab or the field.  CXC does have a lab in the Madison area, and the ability to perform a VO2 max test and extrapolate much more exact estimated Heart Rate training zones based upon various measures of ventilation during a test.  The reason I say estimated Heart Rate training zones is that each day you are likely to have slight variations in your training zones based upon a number of factors, including hydration level, overall stress, work out temperature, recovery from previous workouts, etc.  But, physiological testing is able to give a much better estimate of your zones than the formulas used by Karvonen or those adopted by most multi-sport training watches.

If you want to dial in your training zones as precisely as possible, a physiological test in a lab is the way to go.  If you want to get in the ballpark, we can suggest using some of Karvonen’s work combined with simple field tests for your max heart rate and then taking your resting heart rate for a few mornings after you wake when it is at a relatively low level.


Use the highest number recorded on a heart rate monitor during a VO2 Max Test, intensity workout, race or time trials.


Do a simple field test.  Run or bike up a moderately steep hill for 2-4 minutes all out.  Do this twice.  Use a heart rate monitor and record your efforts.  Your highest heart rate should be very close to the max you will achieve in training, races, max tests, etc.


Take your waking heart rate for a week or two and use your lowest number.


Subtract your resting heart rate from your max to get your Reserve Heart Rate (RHR).

Then for your heart rate zones, add your resting heart rate and percents of your RHR.

Level 1 is ~<72.5%

Level 2 is ~72.5-82.5%

Level 3 is ~82.5-87.5%

Level 4 is ~87.5-92.5%

Level 5 is ~92.5% and up

This should get you in the ballpark, until you have an opportunity to get in a lab.

Why You Should Measure HRV Through the Off-Season

by SIMON WEGERIFTrainingPeaks

Simon Wegerif is a serial entrepreneur, inventor, and biomedical engineer. He was previously an executive with Philips Electronics in the UK and Silicon Valley. Simon is a competitive cyclist and has also completed a number of triathlons including Ironman distance. He created ithlete, the leading, scientifically founded HRV app in 2009 after identifying an opportunity for using HRV in his own training. He is considered an expert on the topic, having read over 1000 papers and frequently consults with industry experts.

You might consider HRV to be a tool solely for measuring overtraining, but you can learn valuable lessons for the season to come during the off-season.

Heart rate variability (HRV) is a relatively new method for assessing the effects of stress on your body. It involves measuring the time between heartbeats, which varies as you breathe in and out. Research increasingly links a high HRV (as in, more variation in the intervals between heartbeats) to good health and a high level of fitness, while decreased HRV (more regular, mechanical intervals) is linked to stress, fatigue, and even burnout.

Many athletes think of HRV a tool to avoid overtraining during the build-up to key events. However, HRV is equally capable of detecting other forms of stress on the body. This can be very useful in the off-season, allowing you to fine-tune your lifestyle so that you can recover more quickly when your training ramps up in the spring.

You can reset your baseline ready for the new season

A period of light training will reset your HRV baseline to a known starting point for next season. As the example below shows that, after three weeks, this recreational athlete’s HRV Average has settled at 77.3 and their resting heart rate at 72.6 bpm. These measures were taken in the standing position, hence the relatively high resting HR (it would be 10-15 beats lower lying down, however, HRV is best measured in an upright position). It’s recommended that endurance athletes take their HRV readings in an upright position, either sitting or standing comfortably, just after waking.

Test the impact of lifestyle changes independent of training

As all good scientists will tell you – change just one thing at a time and note the effect! The lack of large training loads allows you to try changing some of the key factors influencing recovery, and find out which have the largest effect:


So much has been written about the importance of sleep for recovery, but having a metric like HRV lets you see the effect graphically, and this will reinforce your motivation & commitment to pay attention to sleep hygiene.


The benefit of a diet with more fresh vegetables, fish or reduced refined carbohydrates will make itself visible on your HRV, and help to reinforce good habits going forward.

Stress management

For most recreational athletes (and quite a few elites), mental, emotional and general lifestyle place a bigger stress on the body than training does. So being able to manage stress is very important, not only to give yourself the biggest tolerance for training, but for overall quality of life and happiness in general. Mental stress is caused by the difference between the load placed upon us, and our perceived ability to cope, so there are two ends to work on! Techniques such as mindfulness (i.e. focussing on the present moment), deep breathing, yoga, Pilates and even open water swimming are all powerful tools that improve our perception. You may be surprised at how large an effect one of these has on your HRV.

You can watch your baseline rise with purely aerobic training

Watching your HRV rise (and subsequently your resting HR fall) can act as a powerful motivator to keep the hours of long slow distance coming, when the thought of either going outside in bad weather or facing the monotony of indoor trainers seems an unappealing prospect.

Good HRV software (like the ithlete app) can also help you identify when your training volume is increasing too rapidly, by associating HRV changes with increases in your Acute:Chronic training load ratio (TSB) as shown in the chart below taken from the ithlete Pro™ app. You should also find that as your HRV baseline rises during recovery (The 8-15 of March in this example), so does your resilience to all forms of stress.

You can detect early signs of illness & take action

Training in adverse conditions (especially cold and wet) makes you more susceptible to colds and upper respiratory tract infections. HRV is a great barometer of when your immune system is becoming mobilized and can often give you a day’s heads up that allows you to wrap up warm, take some favored supplements (zinc, vitamin C, honey & lemon, Echinacea, etc.) and get an early night to give yourself the best chance of fighting it off.

The chart below shows an example of sudden sickness following an early-season training camp when the athlete’s immune system was in a weakened state. But it also shows how quickly recovery took place when the training was removed:

Although illness is usually accompanied by a drop in HRV (followed by a spike in resting HR), a well-conducted research study in swimmers showed a rise in HRV a few days before the cold symptoms started. This possibly represents an anti-inflammatory reaction by the body and is something that has been reported to us at ithlete by a few users, so worth looking out for.


If you’re not already a regular HRV user, the off-season is the perfect time to start. In the absence of intensive training, you can experiment with lifestyle changes and build a baseline that will stand you in good stead as a reference for when training intensifies during spring.

Buying a GPS/HRM Sport Watch – The Basics

by FasterSkier

The functions are many on our wrist-worn data collecting training tools. And in some ways, the putative cause for that post-training bliss might be the very data stored on that GPS/HRM device when uploaded to your training analysis app. Maybe you notched a PR, or simply logged 10,000 feet of vertical gain during that offseason ski tour. Or … you simply like pinpointing precisely where your heart rate spiked during that pre-Birkie time trial.

Whatever your fancy, these watches marketed towards backcountry adventurers, endurance athletes, and training log devotees provide data for real-time feedback and week to week, month to month, and annual progression trends when it comes to training.

Like many commodities in the outdoor sport industry, brand loyalty can be divisive. The bottom line is that many companies make high functioning and reliable wrist-worn devices to track distance and speed with GPS and collect heart rate data. These devices come in many flavors; some geared more towards runners, and others towards those who demand an altitude reading and GPS waypoints for mountain navigation.

Andy Newell, founder of Nordic Team Solutions and longtime World Cup skier, had this to say about using a GPS/HRM watch for cross-country ski training.

“I use a HR monitor but almost never use any GPS function,” Newell wrote about how he uses his sport watch. “All I need is a watch that can time and let me know how many minutes I am in each zone. I turn off the GPS because then I don’t need to charge the watch as often. If I’m in the backcountry I just use an app like Gaia. I think for the most part elite xc skiers do not use GPS too often with their ski training because resistance is such a huge variable on snow and can even be variable on the roads depending on the conditions. It’s the same reason why skiers log our training in hours and minutes rather than miles or kilometers like a cyclist or runner.”

We asked Newell to query his collegiate group of skiers training in Bozeman, MT. this summer about what type of device they use and the basics about their functionality. Before we expand the discussion, here are the results.

What Type of heart rate monitor do you use? Please indicate brand and model.

  • Suunto Spartan sport
  • Garmin Premium HR Monitor-Soft Strap
  • Garmin Fenix 5s plus watch with latest Triathlon strap
  • Garmin Forerunner 735xt
  • Polar strap with Apple watch
  • Suunto Ambit 3 peak and sport
  • Garmin HRM-Run (HRM4)

In your opinion what is the best function of the watch? i.e. heart rate, GPS, multi sport, heart rate zone guidelines.

  • Heart rate and GPS
  • Heart Rate
  • The watch features many different types of sports and activities, it can track HRV, and it has the ability to be fully customized to fit the needs of most any athlete.
  • Very easy display to look at interval time and heart rate.
  • Multi sport
  • The best function of my watch (Suunto Spartan) is that it monitors my sleep. I am able to see my average resting heart rate, the amount of hours I have slept and how many of those hours were ‘deep sleep.’ This is a tool that helps me monitor my recovery from training load.
  • Heart rate and GPS

Do you download and look at your heart rate data? Yes or No. If yes, please indicate how you use that data. i.e. Keep track of interval data, race data, keep a training log.

  • Yes, to see time at each level and how quickly I recover.
  • I will look at my max and average HRs for interval sessions/races and put them in my training log. I also record a morning HR in my log, but take it by hand. I typically do not download and look at the graphs, though.
  • Yes I look to see what my max heart rate is and my average heart rate at the end of the workout.
  • Yes I look at what levels I was skiing at during the session
  • Yes. I use that data to determine if I was in the proper zone for specific workouts. I also record my Max HR during races and time trials in my training log, out of curiosity, taking the conditions into consideration, but to see how hard I push myself.
  • No, I haven’t in the past but I’ve started to now. I usually just look after the workout to see how hard I was working and if that correlates with how I was feeling. I’m still trying to understand it all 🙂

If your watch could do something super rad that it currently does not do… what would that be?

  • Have music downloaded on it.
  • Dispense peanut M&Ms.
  • Be somehow able to measure lactate.
  • My watch does everything I need it to do so I would have to go with voice commands.
  • I would want it to show my current speed which it does not.
  • Play music/connect to Bluetooth headphones.
  • My watch is super sick already!! Not sure if I have any ideas.

As Newell stated, if a watch has HRM capabilities and the ability to time duration in each specific heart rate training zone, you should be good to go. The GPS features come in handy if you want data on distance traveled, total ascent or descent, and speed. Or if you tend to be the type of athlete that mixes adventuring with traditional “training”, the GPS can be a precision navigation device. As a basic yet functional training tool, GPS is not a necessary condition. However, if you don’t mind charging your watch more often, the added bonus of GPS data is a nice feature: it allows for proper analysis of pacing strategy during training or racing.

“Both are nice info to have, but the main focus today is duration,” Øyvind B. Sandbakk explained about having athletes collect data on kilometers skied or duration of the training session. Sandbakk is the managing director at the Centre for Elite Sports Research at the Norwegian University of Science and Technology (NTNU) in Trondheim and the head of research and development at the Norwegian Olympic Sports Centre (Olympiatoppen).

Like Newell’s athletes, we also asked Sandbakk what feature he would like to see incorporated into sport watches.

“From normal sport watches they use GPS for speed in a given terrain, and heart rate for indications of metabolic intensity,” wrote Sandbakk. “Ideally, we should also have integrated Inertial movement units (IMUs) in the future, that can detect what sub-technique they use and temporal patterns (cycle rate and length). This would also allow us to indicate the external power they are using (watts).”

Style options are many for GPS/HRM watches. The mainstays of the industry are Polar, Garmin, and Sunnto. You can add Apple, Coros, and Fitbit among others to the list. It’s worth taking time to determine your budget and desired features. For backcountry skiers/mountaineers, the added bonus of a barometer is nice for more accurate altitude readings. That comes at a cost. Which reminds us that these watches can be expensive.

A basic HRM can be found in the $50-$60 range. Adding in a GPS and more functionality can push the wrist-bling into the $250-$300 range. Add in features like a thermometer, safety and tracking, and music storage to name a few and it’s easy to launch into the $400-$600 stratosphere.

For runners, having built in GPS is handy for speed and pacing data. For trail running specifically, here is how Carbondale based FasterSkier writer Rachel Perkins uses her sports watch.

“I pay a lot more attention to mileage and vertical gain than I do during the ski season, but I rely mostly on HR for pacing since mile splits are pretty irrelevant,” Perkins said. “On roads, I rarely pay attention to HR just because pace and effort are so much more directly correlated.”

When considering a watch, the standard is to shy away from relying on an optical sensor HRM. The optical sensor sits on the underside of the watch and makes direct contact with the wrist. Even with technological advances, optical sensors still do not rival the accuracy of using a traditional chest strap to measure heart rate. (Trail Runner Magazine ran a solid story on why optical HRMs still struggle with accuracy.)

“But here’s the big problem—the errors are not consistent,” David Roche wrote in Trail Runner about the inconsistent readings from wrist positioned optical HRM sensors. “If it was always 5% low or 5% high, we could use that information (you’re probably having flashbacks to the accuracy v. precision distinction from high-school science class). Instead, it’s all over the place, and since 5% is an average, sometimes it might read 190 or something that makes an athlete write a panicked entry in their training log.

“It’s kind of like Michael Cohen testimony. First it says one thing, then it says another, so even if it’s right one time, how can you trust it? In this analogy, I’m not sure if I’m CSPAN or Alexandria Ocasio-Cortez.”

Political preferences aside, not wearing a chest strap is handy, but for accuracy, the chest strap is the way to go.

If you are looking for a new sports watch and in need a deep dive review, D.C. Rainmaker is the best place to start.

The imagination can run wild when considering the possibilities of collecting data from our sport watches and becoming a more efficient and stronger skier. The type of IMU datasets Sandbakk hopes for may appear sooner than we think in the exploding marketplace for wearable fitness technology. But for now, if you are just entering the market and want specific heart rate data with no GPS functionality, a basic HRM may be all you need to track your training and improve. For parents shelling out cash for that motivated high school athlete, that might leave more money for new ski boots if that teen is hitting their growth spurt.

How to Raise Threshold Heart Rate

I am a master’s skier, mid 40’s, and have been racing for about 30 years. In the past, I have been fairly successful. In the past 3-4 years, my threshold HR has gone down significantly. It used to be 165, now it’s much lower. I recently did two races, a 30 k and a 50 k, and my average HR was 152. I usually do intervals twice a week. I’m having problems with my quads really burning a lot, so that I can’t push hard enough to raise my HR very high. I have tried Incorporating more recovery into all my training, but it doesn’t seem to make a difference. Do I need to do short intervals, 30 sec-1 min with short rest to raise my HR without my legs burning so much and then gradually increase them? I do a lot of endurance, 14-18 hours total training/week.


Certainly try to shorten the intervals in the manner you outlined, that is, make them long enough to get the heart-rate up, but short enough so that you aren’t feeling fatigued in the legs right immediately. With shorter intervals, you would want to consider adding more repetitions so that you maintain training volume so as not to get a de-training effect.

Strength training. I don’t know if you are currently engaged in a strength-training regime, but having a strength plan that targets the leg and core muscles may help solve your leg-problem. You can even devote one strength session entirely to legs and reserve another day for arms to target the legs more dramatically.

After tweaking your training to account for these two suggestions over the next 6-7 weeks, I would re-test and reevaluate your threshold HR to see if catering to the limiting factor (legs) provides positive feedback. Hopefully you will see improvements in your threshold HR and/or quads.

Karmen M. Whitham
CXC Development Coach


Factors that Influence Heart Rate During Outdoor Training

The following factors affect your heart rate during outdoor training:

ACTIVITY. Heart rate can change across activities, due to different muscle mass involved, level of experience and technical proficiency. Running typically elicits the highest maximum heart rate during a stress test, whereas cycling and paddling maximum heart rates can be 10-15 beats lower during a similar test. This means that you may need to adjust your training heart rate intensities by 5-10 beats for activities other than running.

HEAT AND HUMIDITY. Temperature and humidity will influence your heart rate. As the environment gets warmer and more humid, heart rate will gradually increase throughout your activity, even if your pace doesn’t change. This is due to your “air-conditioning” and level of hydration. You produce a lot of energy in the form of heat when you move and this heat needs to be dissipated, typically via sweating. Humidity reduces the effectiveness of sweating, resulting in an increase in body temperature, and thus an increase in heart rate. Even if the humidity is low, heart rate will still be elevated, due the extra work the heart must do to help cool your body. It’s not uncommon for heart rates to be 5-10 beats above normal ranges in these conditions. Use your heart rate combined with perceived exertion and subjective feeling to set an appropriate pace.

HYDRATION. Failing to stay hydrated can result in an increase in heart rate, as your blood volume decreases and your body runs low on the fluids needed to maintain body temperature. Dehydration can occur in cold as well as hot environments. If you notice your heart rate increasing with no change in pace or other variables, then increase your fluid intake.

ALTITUDE. The lower air pressure at altitude means there is less pressure to drive oxygen into your lungs. Less pressure means your heart has to work harder to deliver enough oxygen to your working muscles. The result is a higher heart rate at a given pace. Fortunately, your body adapts to higher altitude in several days to 2 weeks, but if you’re only at altitude briefly, you’ll need to slow your pace to keep your heart rate in the proper range. It also takes longer to recover from a hard effort at altitude, so rest periods may need to be longer.

FUEL. Your body is always using a combination of carbohydrates, fats and proteins for energy production. As the exercise intensity increases, you burn more carbohydrates and less fat (protein metabolism is always fairly small). Even at low intensities, you need some carbohydrate to burn fats (fats burn in the flame of carbohydrate). What does this have to do with heart rate? If you start to run low on carbohydrate, it will become difficult to maintain your pace at a given heart rate. Your perceived exertion and subjective feeling will increase, but your heart rate will be falling. This is informally called “bonking” and can be remedied by eating foods high in carbohydrate. As a rule of thumb, always bring along some form of ingestible energy on any outing lasting more than 2 hours.

Training Heart Rate Range (THRR)

Monitoring your heart rate allows you to maximize the effectiveness of your training. By knowing your Training Heart Rate Range (THRR), you can adjust your effort to work within those values, based on your goals for each workout.

Use the formulas on this page to determine your approximate THRR. For more accurate calculations, visit your physician and have a stress test done.

To determine your THRR you need to first determine the following values:

  • Maximum Heart Rate (MHR)
  • Resting Heart Rate (RHR)
  • Heart Rate Reserve (HRR)


The rule of thumb for MHR used to be 220 minus your age. However, recent studies have shown 205.8 – (0.685 × age) to be a more accurate guide.¹

¹ The Surprising History of the “HRmax=220-age” Equation, Robert A. Robergs and Roberto Landwehr, Journal of Exercise Physiology Volume 5 Number 2 May 2002.

You can also:

• Run or bike up a steep hill for about 2 minutes twice. Use your heart rate monitor or count your heart rate immediately after you stop each time for 10 seconds and multiply it by 6.

• Use the highest number you have recorded during Max VO2 Test, intensity workout, race or time trials.

To determine your RHR, take your pulse first thing in the morning, before engaging in any significant activity (ideally, before you get out of bed). For greater accuracy, do this for several days and average the results.

HRR = MHR minus RHR

Training Heart Rate Range

To determine your THRR, take percentages of your HRR and add them to your RHR. The percentage you take depends on whether you are doing aerobic or anaerobic threshold training:

  • For aerobic training, take 50–75% of your HRR and add it to your RHR
  • For anaerobic threshold training, take 80–85% or your HRR and add it to your RHR


A 50-year-old with an RHR of 62 results in the following values:

  • MHR: 205.8 – (0.685 x 50) = 172
  • HRR: 172 – 62 = 110
  • THRR for Aerobic Training: 115–143 beats per minute (bpm)
  • THRR for Anaerobic Threshold Training: 148–154 bpm



Post Workout Insomnia

Q: I often don’t sleep well after a 45-60 minute midday or morning weight lifting workout. I try to stay fueled and hydrated afterwards. My schedule has me doing weights twice a week. I’ll wake up hours early. I’ve read that it’s caused by too much cortisol, adrenaline, and norepinephrine. Am I overdoing it? My workout schedule is currently 7-8 hrs wk and I sleep well otherwise after OD or interval workouts. Having a beer in the evening helps but causes other issues like dehydration and some sleep apnea. Should I back off and have more frequent shorter weight sessions, take a sleep aid like chamomile, melatonin, or something else like eating before bed? I’m 47, a fairly fit ectomorph, and am training for some ski marathons.
Mike in AK

A: In general, exercise increases cortisol, norepinephrine and adrenaline which makes it difficult to fall asleep…if your workout is close to bedtime. Since your workout session is morning/midday I would assume that acute hormonal response to exercise is not the culprit to your sleeplessness. However, it is a possibility if your morning session is particularly taxing.

Over-exercising or improper recovery can also cause insomnia. Nevertheless, I wouldn’t be quick to diagnose overtraining with just this one symptom. Classic overtraining symptoms include low energy, generally feeling worn out, prolonged muscle soreness, frequently sick, irritability, unintentional weight loss and higher resting heart rate. If you are experiencing more than two of these, you may be overdoing it. In that case, go lighter on your workouts and see if your sleeping and training become better.


If you are not tracking your resting heart rate in the morning, doing so can be a great tool to monitor your body’s internal stress. If you find that your heart rate spikes one morning, that can be a sign that your body has not come back to homeostasis (full recovery). There are several methods for obtaining the resting heart rate. The method I suggest is to lay flat on your back for 3 minutes, then come to standing and stand still for another 3 minutes. Do this first thing in the morning after you wake up. Grab the average heart rate for the total 6 minutes to get your heart rate average for the day.

Sleeping aids are certainly an option, through you don’t want to rely on them. Understanding that they will be a “quick-fix” and may mask underlying sleeping problems is important.

First I would suggest trying to fit the strength session in earlier in the day to see if that changes anything. If you’re still having problems, I would try shortening or lightening your sessions. Next, monitor your morning heart rates for a few weeks to check that they are normal, consistent and within a healthy range for you.

Goodnight and good luck!!

Karmen M. Whitham
CXC Development Coach

The Benefit of Bringing Heart Rate Down Between Interval Sets

The recovery period between intervals is an extremely important part of the workout. It allows us to focus on pushing that race pace without overstressing the body. By breaking up that workload we are able to spend more time in that Level 4 zone without the lingering effects of a full length race effort.

The 120 bpm mark is set to be solidly in Level 1 territory for athletes of all abilities and is used as a mark to show that full recovery is attained between interval sets. One sign of potential overtraining is an inability to recover between sets (an elevated heart rate for many minutes longer than expected). That being said, the 120 bpm mark is arbitrary and not specific to you. We would expect that you take at least 2 min to recover between each interval or until your heart rate is back to Level 1.