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6 Keys to Optimize Your Cardiovascular Training for Enhanced Fitness & Fat Reduction

Note from Brian Calkins: What follows is the full and unedited interview that I had the privilege to do with one of the country's top fitness professionals, Doug Jackson, of Coral Springs, Florida. This original transcript was published in his newsletter in February, 2005.


Doug Jackson: If you're interested in cardiovascular conditioning and fat loss, it would be wise to read the newsletter today.

I’ve managed to get Brian Calkins, Cincinnati’s most in-demand trainer and Men's Fitness contributor, to answer some specialized questions regarding cardiovascular conditioning and fat loss. I had the opportunity to visit with Brian a few weeks ago and check out his operation. After the visit, I knew I had to get him into the newsletter. Hey, what can I say? Only the best for my readers. Here goes:

Jackson: Brian, you’ve developed such a great reputation for real-world results with cardio training that you’ve actually been endorsed by Polar (the world's leading manufacturer of cardiovascular monitoring systems). From your perspective, how does cardio training fit together with total fitness?  

Calkins: Cardiovascular training is extremely important and the benefits numerous. From a health perspective, I would only be scratching the surface by mentioning benefits that include improvement in blood pressure, increases in HDL (good) cholesterol and decreases in LDL (bad) cholesterol, reduced body fat, a decreased glucose-stimulated insulin response, improvement in heart and lung function and efficiency, and decreases in anxiety, tension, and depression. And all of these benefits combine to help lower a person’s risk of cardiovascular disease (among many other diseases including at least 11 known cancers) by reducing risk factors like obesity, hypertension, and high blood cholesterol. 

From a fitness point of view, cardiovascular exercise serves as the foundation for improvement in our activities of daily living, sports, and other outdoor activities such as tennis, golf, skiing, dancing, basketball, volleyball, boxing, hiking, and strength training programs significantly benefit from cardiovascular exercise. Enjoyment of day-to-day and physical activities also greatly increases because you will have more stamina, less fatigue and less risk of injury.

In terms of body composition, cardiovascular training dramatically improves the body’s ability to release & burn fat as a primary source of fuel, PROVIDED that the training follows the appropriate level of intensity. 

Jackson: What is the first key to optimizing a person’s cardio training?  

Calkins: The first key is very simple; a person MUST monitor their intensity of cardiovascular training. I find that most people, due to lack of guidance or instruction, do not monitor their intensity when elevating their heart rate. To improve your health, fitness & body, you absolutely must have a way of determining how hard you should exercise. And by far the easiest and most accurate way to monitor one’s cardiovascular intensity level is through the use of a heart rate monitor.

It used to be that heart rate monitors were very expensive. My very first one cost over $300. Today you can get one as accurate as a hospital EKG monitoring system for as little as $50. 

Jackson: Okay, so you recommend that clients use a heart rate monitor for the most effective aerobic training, what’s the next key to enhancing fitness & fat reduction?

Calkins: Well, once someone has a heart rate monitor, they simply need to train (aerobically) within their target heart rate zone. I’ll get to the specifics of determining how your readers can determine their appropriate exercise target heart rate in a moment. 

But first, I find many people who say one of two things about cardiovascular training, either (1) “I hate cardiovascular exercise,” or (2) “I’m not seeing results from my cardio.” This first, “I hate cardio” group tends to be exercising far too intensely which makes one’s cardio extremely uncomfortable. Once people understand & follow their individualized training zone, call Target Heart Rate (THZ), they report a dramatic change in terms of their enjoyment of cardio training. See, what the “I hate cardio” group was never taught is that when they exceed their appropriate training zone their bodies shift from burning fat into burning blood sugar (glucose). And when someone is burning mostly glucose, cardiovascular exercise tends to become very uncomfortable to sustain, both during a single exercise session and even more so with repeated bouts of too intense exercise.  

In working with the latter “I’m not seeing results” group, I find that they simply have not been stimulating their heart rate enough to facilitate significant cardiovascular benefit. The perfect example of this is someone who reads in a magazine that the secret to losing weight and improving their health is through moderate walking. Now don’t misunderstand me, I’m not saying that walking is bad. In some cases it’s extremely beneficial, for example, for very sedentary, obese or elderly individuals, walking is a tremendous start to improving fitness. The challenge lies in the fact that our bodies adapt very quickly to the stimulus (exercise) we place upon them. Once your body adapts to a given stimulus, you have to then modify and add just a little bit more to it. 

And the best way to determine the appropriate stimulus level (intensity) is to use the Karvonen Heart Rate Formula. Dr Karvonen, in my opinion, has the most accurate method for determining the appropriate cardiovascular intensity level as his formula takes into account one’s current fitness level through resting heart rate.

I strongly recommend that people contact a qualified fitness professional and ask him or her to determine their appropriate target heart rate (THZ) through the use of the Karvonen Formula. For those who aren’t working with a quality trainer, I have the formula on my site where they can simply type in their age and resting heart rate and the formula gives them their specific training zone. .

And as a person becomes more conditioned (more fit) their target heart rate will change as their heart and lungs improve. This is one reason why walking may be appropriate for just a short period of time if the goal is to improve fitness & lose excess body fat.  

Jackson: Okay, you know I don’t shy away from controversy and I won’t avoid it here either. You know there is a lot of debate about whether someone should do cardio first and then weight train after the cardio or vice versa. My readers probably know my opinion on this, but I’m open to differing opinions (some people may dispute that). So what’s your take on the proper sequence?  

Calkins: Always resistance train (weight training or strength training) first, followed by cardiovascular training, especially if the goal includes losing body fat. Here’s why: Our bodies use 2 primary sources of energy to fuel most of our activity, blood glucose and body fat. And the body will always use glucose first before using body fat; it’s just an easier source of fuel to access.  

So when we perform cardiovascular exercise our body uses either glucose or stored body fat as its fuel to perform the work. Strength training, on the other hand, uses primarily a glucose energy system (blood sugar) and very little fat as its fuel source.  

So how does this play out in real world exercise? If someone was to start their exercise session with cardio, during the training session glucose will be utilized as the primary fuel source until the point that blood sugar is depleted. Only then will the body begin to use its fat reserve to fuel the cardio session. And chances are if cardio is performed first, the exercise session may not completely deplete glucose and tap into body fat. Now, once a person is finished with cardio and moves into their strength training, they may have very little energy left in reserve to get through resistance training since much of the body’s glucose was during their cardio training used (remember, glucose is the primary energy source for weight training).  

Now let’s look at the opposite scenario, starting with resistance training and finishing with cardio. In this scenario, the exerciser uses most, and in some cases all, of their available glucose during the strength training session. Now as they progress into their cardio activity, they will quickly begin using stored body fat as fuel.  

So people should remember, strength training uses glucose for fuel, cardiovascular training uses either glucose or body fat, but prefers glucose if it’s available. Doing the strength training first followed by cardio training allows the body to utilize excess body fat most effectively.  

Jackson: Right on. Okay, I know that you personalize all of your clients’ cardio programs and make it specific to their background and goals. Ultimately, that’s what makes personal training personal. However, do you think you could outline a sample program that my readers might be able to try out?  

Calkins: Absolutely. A very simple yet extremely effective cardio program to follow is one where you vary both the intensity and time of sessions. Here is a great schedule to follow in a given week: 

Cardio Session One: Perform strength training first, followed by a long (45 – 60 minutes), but lower intensity cardiovascular session. Lower intensity specifically means elevating your heart rate at 60 – 70% of your max heart rate as determined by the Karvonen Formula.  

Cardio Session Two: Strength training followed by 25 – 35 minutes of a moderate intensity cardio session. A moderate intensity falls into the 70 – 80% range of your maximum heart rate.  

Cardio Session Three: Strength training followed by a short (20 minutes) intense bout of cardio training. In this session, an exerciser would incorporate 3 - 4 very intense, but short (60 – 90 seconds), sprints of up to 95% of your max heart rate as modified by the Karvonen Formula.  

For example, a 30 year old person with a resting heart rate of 60 would incorporate this routine in the following way.

(And again, readers of your newsletter can go to the formula on my site and enter their age and resting heart rate, then follow the heart rate range for their specific intensity levels.

Day one would include a long cardio session (45 – 60 minutes) at 60 – 70 percent of max heart rate (MHR); specifically the THZ for the workout would fall between 138 – 151 beats per minute for our 30 year old person with a resting heart rate of 60, in this example.  

Day two incorporates a moderate session (25 – 35 minutes) between 70 – 80 percent of MHR, or a THZ of 151 – 164. 

On Day three, the plan calls for a short, but intense session. Specifically, the 20 minutes breaks down as follows: maintain a heart rate between 60 - 70% of max for the first 5 minutes (THZ = 138 – 151), then begin the first sprint, lasting for 60 – 90 seconds and shooting for up to 95% of MHR, or a THZ somewhere between 164 – 184 max. After sprinting, allow your heart rate to come back down to 60 - 70% (again THZ = 138 – 151). Then repeat 2 more times at the 10 minute mark and again at the 15 minute mark. Once you hit 20 minutes, you’re finished with the session and you’re energy will feel amazingly elevated throughout the day! 

IMPORTANT NOTE: Now, if you’re new to exercise, give yourself plenty of time, maybe 2-3 months, for your body to work up to this type of cardio training. And of course, check with both your doctor and a well qualified fitness professional for direction & advice on your specific readiness for the day 3 workout.  

Jackson: Is there a better time of the day to do your cardio if you want to optimize the effects of your training? 

Calkins: Ultimately, the best time to work out is specific to when a person feels at his or her best. However, there is a slight metabolic advantage to working out first thing in the morning on an empty stomach, provided that you have enough fuel from the previous day’s nutrition to complete the session. 

If you feel like you need some additional nutrients to make it through a training session first thing in the morning, attempt to eat a little protein and very few carbs or fat. The protein will feed your working muscles while allowing you to burn fat throughout the exercise session. My clients tend to consume a shake made up of about 30 grams of protein (no carbs or fat) just before their workout in the morning.  

Jackson: Any other secrets associated with cardio training that you offer your clients?  

Calkins: There is another little secret that works for some people and it’s the use of caffeine. Now it doesn’t work for everyone, primarily if someone is already a regular consumer of caffeine.  

But if you’re not currently drinking coffee or ingesting some other source of caffeine, you would experience an enhancement in both performance (ease at which you complete a session) and the rate in which your body releases and uses fat during your cardio session by consuming a small to moderate amount of caffeine. You just want to make sure you cycle on & off the use of caffeine every 4 weeks or so, otherwise you’re body will become accustomed to it, thus losing the benefit.  

Jackson: Brian, this is the last one, I promise. I know that you are doing some awesome small group classes that empower people to transform their bodies and their health. Are there any openings for those? Since only a small percentage of my readers would live close enough to you in Cincinnati to meet one on one or in a small group, is there anything else they can do to continue benefiting from your expertise?  

Calkins: Thanks for asking Doug. I have new classes forming all the time for my Complete Fitness Transformation groups. The class is ideal for people who are looking for the education and empowerment in terms of taking complete control over their health, fitness & how their body looks & functions.

For people outside of the Cincinnati area, they can sign up for my newsletter @ where I share additional insights through periodic updates on health & fitness. 

As we wrap up, I just want to let you know that it has been an absolute pleasure getting to know you over the past several months. I’ve mentioned this to you before, but it’s worth repeating, I’m very impressed with your career and the things you’ve been able to accomplish in such a short period of time. I consider myself lucky to be both a friend and colleague as a fellow fitness professionals. And I anticipate some great things from you in the very near future! 

Doug’s note: For more information about how Brian Calkins, Cincinnati’s top trainer, is helping many people improve their fitness and change their lives for the better, visit

Additional Resources:

The Karvonen Heart Rate Formula can be found by clicking here.

More information on Heart Rate Monitors can be read here on the site.