I have no idea what mine is and if you think you know yours, it’s very likely you’re incorrect.
Maximum Heart Rate (MHR) has long been used for competitive athletes as a tool for monitoring a training regimen designed to improve performance. If an athlete knows his MHR (the highest heart rate he can achieve) he can use that to aim to exercise at a level in which his heart rate is over 80% of MHR, which is the sweet spot for performance training. Meaning, an athlete can achieve optimal performance gains if he exercises at that level on his high-intensity training days. Athletes and their trainers go through great pains to carefully determine, and constantly recalibrate, an athlete’s MHR.
But, with the emergence of wearable fitness trackers, heart rate monitors, exercise equipment with built-in monitors and group classes displaying participants’ heart rates on giant screens, MHR has become all the rage for amateur athletes, fitness buffs, weekend warriors and on-again, off-again exercisers alike. But just because you can measure and track something doesn’t mean it has value. I don’t track my exercise heart rate because I know it has little value:
- The formulae (there are several) used to calculate an individual’s MHR, which use age as a variable, are known to be inaccurate.
- MHR formulae can’t encompass non age-related variables known to affect heart rates during exercise: genes, number of muscle groups involved in the exercise, prescription and OTC medications, body type and altitude.
- An individual’s MHR can fluctuate day-to-day in response to sleep quality and stress levels or hour-to-hour based on diet choices such as caffeine, supplements and hydration levels.
The Case Against MHR
You may ask what’s the harm in using MHR as a benchmark understanding the calculation may be off by a few beats per minute? Well, I don’t use MHR with my clients and warn them not to try to use it on their own because I know relying on it can actually be detrimental:
- If the MHR is underestimated for an individual, she could be unnecessarily holding back, resulting in unproductive workouts and a delay in achieving fitness goals.
- If the MHR is overestimated, she’s encouraged to workout at levels higher than she should or beyond her capabilities. This can lead to discouragement, a perception that all exercise is too difficult and elevated post-workout soreness. Worse, it raises risks for injury and cardiac or pulmonary problems.
Even if the MHR is accurate for an individual, the average gym-goer isn’t likely to know what to do with that information. Athletes do use it to make sure they’re working hard enough on high intensity days. But, perhaps more importantly, they also use it to make sure they’re not working too hard on low-intensity and recovery days. Athletes exercise at far less than 80% MHR for a majority of their total weekly workout time. To do more than that would result in injury and over-training.
Unfortunately, all the hype currently surrounding MHR encourages people to constantly track heart rates and to exercise at high levels (>60% MHR) during every workout, for as long as possible, several times a week. At best, this leads to exercise burnout. At worst, it leads to serious illness.
So, if we shouldn’t be using MHR, what should we use to make sure we’re working out hard enough to achieve our fitness goals but not too hard so we’re not putting ourselves at unnecessary risk? The answer is the Talk Test – no calculating, no monitors and scientifically proven to work on every person, every time. And it’s so simple:
- Step 1: Choose a 30-50 word recitation you know by heart; examples: “The Pledge of Allegiance,” “Twinkle, Twinkle Little Star,” or “Happy Birthday” recited twice.
- Step 2: After warm-up, when you’re at the pace at which you expect to perform your workout, do your recitation. If you’ve chosen a song, such as “Happy Birthday,” it’s important to speak it as opposed to singing it. You don’t have to recite it at conversation volume but you must speak aloud otherwise the test won’t work. The intensity level according to the Talk Test (with MHR equivalents) are as follows:
- Rest/Low Intensity (<40% MHR): Recitation is easy, no pauses for deep breaths between phrases.
- Moderate Intensity (40-60% MHR): Recitation isn’t difficult but more frequent and deeper breaths between phrases compared to at rest.
- High Intensity (60-80% MHR): Recitation is difficult; taking frequent, deep breaths.
- Very High Intensity (>80% MHR): Can’t do the recitation.
- Step 3: Keep pace, pick up pace or reduce pace based on Talk Test results and your intensity goals for that workout. Repeat test during workout as needed.
We tend to think of intensity only in relation to cardio workouts. But, the Talk Test can be appropriately applied to workouts that fuse cardio with strength or flexibility training (boot camp, HIIT) as well as power-based strength workouts (CrossFit) and fast-paced yoga or Pilates. With that in mind, here’s the breakdown of weekly training by intensity recommended for people who are exercising to achieve basic fitness:
- Rest/Low Intensity: 1-2 days/week
- Moderate Intensity: 3-6 days/week at 60+ mins/day
- High Intensity: 0-4 days/week at 30-60 mins/day
- Very High Intensity: 0-3 days/week at <30 mins/day
Notice one never has to workout at or above 60% MHR in order to achieve fitness. But, if you want to do higher intensity workouts and would like to boost your motivation to push yourself, instead of monitoring your heart rate, use one or more of these scientifically proven strategies to amp up your exercise output:
- Partner up or take a group class
- Listen to your favorite fast-paced music
- Take it outside
Ignore the MHR hype and employ the low-tech, old reliable Talk Test instead. You’ll be fitter and happier for it.