Saturday, December 20, 2014

Am I Burning Fat or Carbs?

Many people are overly concerned about the type of calories they are burning during exercise. Let me first just say that it is important to exercise in ALL heart rate zones. Maybe not all on the same day. I mean, you have to mix it up a bit, have some semblance of a plan in your weekly or monthly routine. But if you are obsessively trying to stay in the fat-burning zone, not only are you doing yourself and your body a serious injustice, you just don't get it.

Okay, first let's remove that big white elephant from the room: There's no such thing as a fat-burning zone. There, said it.

I'll explain in a minute why this is a myth, but first let me say that exercising in this zone, which is typically defined as 65-75% of maximum heart rate (MHR) should definitely be a part of your training repertoire. And when I say training, I am still referring to you folks out there who may not be training for athletic competition, but just want to look and feel good. The 65-75% MHR training zone is necessary to build an aerobic base and to aid in recovery. You can't go hard day after day, not only will you burn out quickly, but you will make yourself more vulnerable to injury and respiratory infections. All people, whether they're elite athletes or your average Joe (or Jane) need to practice the PROS (progression, regularity, overload, and specificity), something that I discuss in my book, DotsoFit Health and Fitness, available at

Below is the table that everyone came to this website to see. Now, skip to the bottom of this post if you want to see why the fat-burning zone is a myth.

Percentage of Calories from Fats and Carbohydrates at Different Exercise Intensities (neglecting protein contribution to energy)
Approximate HR2 Training Zone
% Calories Burned from Carbohydrates
% Calories Burned from Fats
<65% MHR4
65% MHR
70% MHR
75% MHR
75-80% MHR
80-85% MHR (anaerobic threshold)
90% MHR
1 Respiratory Exchange Ratio (RER) is the ratio between carbon dioxide production (VCO2) and oxygen consumption (VO2). RER = VCO2/VO2
2HR = heart rate, 3RHR = resting HR, 4MHR = maximum HR

Let's take our average Joe and we'll even call him Joe. Joe walks for 20 minutes at 3 miles per hour. Thus, 67% of his calories burned are coming from fat and 33% are from carbohydrates. Great, you say. Joe has burned 64 calories from the metabolism of fat and 32 calories from the metabolism of carbohydrates. Better, you say. Wait, read on...

If Joe had doubled his speed to 6 mph for 20 minutes (this is a slow jog, a 10-minute-mile pace), Joe would have burned 46% of his calories from fat and 54% from carbohydrates. However, because Joe is working harder, he is burning more total calories, and the actual numbers come out to be about 90 calories from fat and 104 calories from carbohydrates.

Do you get it now? In this example, Joe burned only 96 calories on his walk, but he burned 194 calories during his jog. Not only that, but Joe burned 90 fat calories on his jog versus only 64 fat calories on his walk.

~Lori Dotson

Copyright © 2013

Saturday, August 16, 2014

Cycling to Strengthen the Leg Muscles Following a Knee Injury

Cycling strengthens your knees by building up the surrounding muscles, providing support and stability to the joint. However, consideration must be given to how you ride—intensity, duration, and proper biomechanics. Following a knee injury, an exercise or rehabilitation program must be designed that can strengthen the leg muscles while reducing the stresses placed on the ligaments and other structures of the knee. Bicycling is a non-weight-bearing, low-impact, controlled exercise that
increases the knee’s range of motion, making it one of the most common exercises recommended by orthopedic doctors after knee injury or surgery. The circular movement also nourishes the knee’s cartilage, contributing to the healing and recovery process (See References 1).

Cycling strengthens the leg muscles, particularly the quadriceps, hamstrings and calf muscles, which reduce weight and pressure at the joint as stronger leg muscles are better able to absorb the forces encountered during daily activities. Strong leg muscles will protect an existing injury and reduce further injury. Cycling can be nearly as effective as weightlifting in increasing muscle strength while placing less stress and strain on the joint.

A cycling rehabilitation program should follow a systematic progression of increasing resistance levels that keep the knee pain-free (See References 2). Start out slowly and gradually increase the resistance on a stationary bike or progress from riding on flat surfaces to climbing hills or interval training on a road bike. Increasing training volume and intensity too quickly can stress the knee joint and negate the benefits of cycling. Also, avoid standing up on the pedals as this puts too much stress on an injured knee. Proper fit and positioning on the bike is essential to avoid stress on the joint, which can cause further injury (See References 3).

Whenever possible seek professional advice. Personal trainers and coaches frequently work in cooperation with physicians and physical therapists to develop safe and effective knee rehabilitation programs. Most bike shops can help you find the right bike and make the necessary adjustments to ensure a proper fit. And finally, cycling clubs offer a community of athletes who have experienced similar challenges and can support you in your efforts.


1 “Cartilage Health - Cycling for Knee Rehabilitation”

2 The Physician and Sports Medicine: Knee Pain and Cycling, Vol. 32, No. 4, April 2004

3 W.D. McLeod, T.A. Blackburn, “Biomechanics of Knee Rehabilitation with Cycling,”
The American Journal of Sports Medicine, 8(3):175-80.

~Lori Dotson, CPT, CPFT, PES, BA, MS
Copyright © 2014

Wednesday, March 5, 2014


“Man. Because he sacrifices his health in order to make money. Then he sacrifices money to recuperate his health. And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then he dies having never really lived.”

~The Dalai Lama

Lori Dotson