One of the most common questions I receive from clients is, “how hard should I be working out to burn the most calories?” The knee-jerk response would seem to be, “as hard as you can,” but the truth is, there is an “optimal” range for exercising if your goal is to maximize caloric expenditure.

To maximize the number of calories you burn during a cardio session, choose a mode of exercise (running, cycle, rowing machine, etc.) that you enjoy (or are willing to put up with for at least 30 mins), and aim to keep your heart rate at about 65-70% of max heart rate. If you use the RPE Scale (rating of perceived exertion), that would equate to a 14-15 (hard). I tell clients that they should feel “comfortably uncomfortable.”

If your goal is sports conditioning (long-distance running or swimming, for example), then high-volume conditioning will address your specific needs (intensity, duration, etc.). High-volume conditioning is a prolonged session (equal to or greater than 60 mins of continues effort at about 65% of max heart rate (13-14 RPE). This is often referred to as “long, slow training.”

If you are unfamiliar with Rating of Perceived Exertion, use the table below as your guide:

6 – no exertion at all (watching television)
7 – light activity (standing, talking on the phone)
8
9 – very light activity (casual walking)
10
11- light activity (warm-up intensity)
12
13- somewhat hard (you are mildly challenged)
14
15- hard (feels difficult, but you can continue without excessive breathlessness)
16
17- very hard: very demanding (out of breath, you don’t want to stay here for long)
18
19- extremely hard (you CAN’T stay here for long; rigorous)
20- maximal effort (all-out effort, only sustainable for very short bouts, akin to doing plyometric power jumps, all-out sprinting, etc.)

These are only two of the many options for maximizing caloric expenditure. High-intensity interval training, Fartlek, sprint intervals, and high-volume circuit training are others I’ll explain in coming blog posts, so stay tuned!


* Note: Blue Sky Gym and the author disclaim any liability for any injury, physical or emotional, suffered during or as a result of exercise or activities recommended. As always, you should use common sense and consult your health professional before beginning any exercise routine or program.

If you really want to make the most of every workout, exercising within your target heart rate zone is a good place to start. In the simplest of terms, your “target zone” is the range that challenges your cardiovascular system, resulting in continual improvements. After consistently training in your zone (six to eight weeks up to several months), you will notice a decrease in resting heart rate. VO2Max, which is the maximum capacity to generate adenosine triphosphate (ATP) aerobically, also improves if you train consistently at 70% of max heart rate or higher.

Target Heart Rate Formulas

Standard Formula:

[220-age] x .60 up to .85 = Target Heart Rate

Here is a real-world example of how target heart rate training can be applied using the basic formula, which is appropriate for most new exercises or those who haven’t exercised for an extended period of time.

Gender and Age: Female, age 35

Current regimen includes running 3-4 times per week (3-4 miles per session) and 2 days of weight training. She has been following a running program, steadily progressing from 1.5 miles to 3.5 miles over the course of several months. She would like to know what her target heart rate range is. Let’s do the math.

Using the 220-age formula indicates that 185 is her max heart rate. Training within a range of 60-80% of max heart rate is most suitable for someone at this stage of training, so multiplying 185 by 80% to get the upper end of the target heart rate, and by 60% to get the lower end, will yield an appropriate range. When I do the math, I get: 111 and 148. This zone may not be challenging enough for her if she has been training for many months. In this case, working in the range of 75-85% of max heart rate, (138-157 bpm) would be appropriate.

Karvonen Formula:

[(Max HR - Resting HR] x .60 and .80) + Resting HR = Target Heart Rate

Example: [185 - 60] x .60 and .80) + 60 = 135 and 155

Use either formula to estimate your own range.

Rating of Perceived Exertion

Another popular method for measuring exercise intensity is the RPE, or rating of perceived exertion. This is your perception of how hard you are working, based on a scale of 1-10, typically, with 1 being very, very easy and 10 being very, very hard. For most individuals, a rating of 6-7 on a 10-pt scale will equate to about 60-70% of max heart rate.

The Talk Test

The “talk test” is another common rating of exercise intensity, and often used in tandem with RPE. Just as the name implies, you should be able to talk, or carry a conversation, while you exercise. Note: you will still be a bit breathless if you are indeed within your target zone. “Comfortably uncomfortable” is the term I like to use. If you can’t string together a few words, you are probably working too hard. If you can relate every detail of last night’s episode of LOST without taking a breath, you aren’t working hard enough.

You can use one of the methods described above to gauge your intensity, or a combination of any/all of them. It is good practice to take note of how you feel at each level of intensity, beginning with your warm-up on up to your target range. Ideally, you will become accustomed to how you feel when you are in your target range and you will know when you are pushing too hard, or not hard enough.

* Note: Blue Sky Gym and the author disclaim any liability for any injury, physical or emotional, suffered during or as a result of exercise or activities recommended. As always, you should use common sense and consult your health professional before beginning any exercise routine or program.