To make gains in the gym, you have to push yourself... Hard.
If your muscles are aching, your lungs are burning, and sweat is oozing from every pore of your body, you know pretty darn well that you’re bringing it in the gym. Could you push yourself even harder? How do you know you’ve really given it everything you’ve got?
The saying goes, “perception is reality,” but is your perception of your effort really accurate and is it reliable enough as an indicator of your true maximum effort? It depends.
High level athletes who have truly pushed their physical limits know when they left it all in the gym or if they’ve mailed it in. Gym newbies really have no idea of their true potential, and typically stop far short of their maximum effort, leaving a slew of gains on the mat.
So, what’s a more reliable way of gauging your intensity during training that applicable to all athletes?
It’s all about training at a certain percentage of your maximum heart rate. With this, you know exactly how hard to push each and every time you step into the gym for maximum gains.
If you’re not sure how to figure out your maximum heart rate, or how to use it to train, that’s ok. We’ll show you how to determine your target heart rate, and then you’ll be able to see if you’re really pushing the envelope with your training!
To start with...
You’re going to need a heart rate monitor. Sure, you can count the number of times your heart beats during a rest period while watching the clock tick, but that’s not always accurate. You might miscount or get distracted while counting by something else going on at the gym.
Using a heart rate monitor provides instant feedback on your current heart rate and is the most reliable way for determining it while in the midst of exercise.
Next, it’s time to learn how to determine your resting heart rate, the number of times your heart beats per minute while your body is at rest. The best times to check your resting heart rate are first thing in the morning after a full night’s sleep and before getting out of bed to start your morning ritual.
Resting heart rate is affected by a lot of things (age, sex, physical fitness, genetics, etc.) but here are some average ranges for resting heart rate according to the National Institute of Health: 
- Children (10 years and older) and adults (including seniors) = 60 - 100 beats per minute
- Well-trained athletes = 40 - 60 beats per minute.
Generally speaking, the lower your resting heart rate is, the more fit you are and the healthier you are.
Finding Your Maximum Heart Rate
To determine your maximum heart rate, subtract your age from 220.
For example, if you are 35 years old, your maximum heart rate would be 220 - 35 = 185 beats per minute.
Why is maximum heart rate important? Basically, it’s the upper limit of what your cardiovascular system can handle during exercise. To get the best results from aerobic exercise, it’s recommended to train within 55 - 85% of your maximum heart rate for at least 20 - 30 minutes. This is referred to as the “target heart rate (HR) zone.”
Following is a table displaying average maximum heart rates based on age along with estimated target heart rate zones. Scroll through the list until you find the age category closest to your actual age and you’ll get a rough idea what your ideal training zone should be. These general guidelines are provided by the American Heart Association: 
|Target Heart Rate|
|Age||Target HR Zone 50-85%||Average Maximum Heart Rate, 100%|
|20 years||100-170 beats per minute||200 beats per minute|
|30 years||95-162 beats per minute||190 beats per minute|
|35 years||93-157 beats per minute||185 beats per minute|
|40 years||90-153 beats per minute||180 beats per minute|
|45 years||88-149 beats per minute||175 beats per minute|
|50 years||85-145 beats per minute||170 beats per minute|
|55 years||83-140 beats per minute||165 beats per minute|
|60 years||80-136 beats per minute||160 beats per minute|
|65 years||78-132 beats per minute||155 beats per minute|
|70 years||75-128 beats per minute||150 beats per minute|
As you can see, your target heart rate zone can vary greatly between 55% and 85%, so let’s take a little deeper look and break the zone down into smaller “mini-zones” to help you better gauge your exertion level should you not have access to your heart rate monitor on a given day.
- Zone 1 (50-60%): “Very comfortable” effort. This should be your zone during your warm up and cool down before and after exercise, as well as your “recovery” periods during high intensity interval training (HIIT).
- Zone 2 (60-70%): “Average” effort. You should still be able to hold a conversation while training in zone 2. Use this zone for training aerobic capacity or cardiac output (i.e. the volume of blood your heart pumps per minute).
- Zone 3 (70-80%): “Above average” effort. Zone 3 is the upper end for developing your aerobic capacity.
- Zone 4 (80-90%): “Hard” effort, but sustainable. This is the point where you shift for training from aerobic to anaerobic and employ a different energy system in your body.
- Zone 5 (90-100%): Maximum effort, you should be going as hard as you can go. This is ideal for developing anaerobic capacity and should be your intensity level when performing tabatas or any other form of HIIT. Be warned, this level is incredibly taxing and you won’t be able to train at this extreme for very long.
Assessing Heart Rate
Knowing your target heart rate will allow you to determine if you’re pushing yourself hard enough or overreaching, and pushing things a bit too hard If your heart rate gets too high and you begin to feel light-headed, dizzy, nauseous, or seeing “stars”, slow down. But if the intensity feels a little too light, ramp things up and push yourself harder.
That’s the beauty of knowing your target heart rate and utilizing that knowledge to enhance your performance. Be aware that if you’re coming back after a long layoff from exercise, especially cardiovascular-type training, you won’t be able to work at the 70-100% range for very long, if at all.
You’ll probably need to spend a couple weeks working out in one of the lower “mini” zones (Zone 1 or 2) and gradually build up to the higher ones. But, after a few months of consistent work, you should be able to comfortably exercise up to 80-85% of your max heart rate and not feel like your chest is going to explode.
A few caveats to this…
If you have a heart condition, in cardiac rehab, or taking any sort of medication, consult your doctor before performing any sort of cardiovascular training, especially if you’re looking to do some HIIT work at some point. All of these factors will impact your target heart rate and maximum heart rate. Your physician will recommend the appropriate type of physical activity given your circumstances.
Finding Your Target Heart Rate
Sometimes you don’t have access to a heart rate monitor, or don’t want to drop hundreds of dollars on the really expensive models. Fortunately, you can still figure out your heart rate while training as well as your target heart rate. Here’s how to do it:
- Use the tips of your first two fingers (not your thumb) to press lightly over the blood vessels on the inside (thumb side) of your wrist.
- Count your pulse (number of beats you feel with your fingers) for 10 seconds.
- Multiply your pulse by 6 to calculate the total beats per minute.
- Make sure that number is somewhere between 55-85% of your maximum heart rate, and you’re all set!
If the number is below your target heart rate zone, kick things up a notch, and if you’re over 85%, maybe dial the intensity back a bit, unless you’re performing HIIT.
Using your heart rate as an indicator of intensity is a sure-fire way to know if you’re exercising hard enough or not. You can drop the big bucks on an expensive heart rate monitor, or get by just as well taking your pulse and watching the clock. Either way, you’ll have a general idea of where you’re at within your target heart rate zone, and that’s the more important thing as opposed to knowing the exact number.
All of that being said, use common sense when exercising. If you’re in your target heart rate zone, but something feels not right (and not just your muscle burning, that’s a good thing!), then absolutely slow down or stop regardless of what your heart rate monitor tells you. Exercise is a lifelong journey, not something that’s meant to send you to the ER.
References1) Nhlbi.nih.gov. (2017). Your Guide To Physical Activity and Your Heart - NHLBI, NIH. [online] Available at: https://www.nhlbi.nih.gov/health/resources/heart/obesity-guide-physical-active-html#tc22
2) Heart.org. (2017). Target Heart Rates. [online] Available at: http://www.heart.org/HEARTORG/HealthyLiving/PhysicalActivity/FitnessBasics/Target-Heart-Rates_UCM_434341_Article.jsp#.Wg4ji2hSzIV