Often, the first change someone makes when they want to lose weight is to start exercising. Although exercise can complement weight loss, it isn't the primary factor that influences long-term weight loss. Nutrition is about 80% of the equation for weight loss, as exercise doesn't burn as many calories as we think it does. The phrase "you can't outrun your fork" is very true.
However, exercise can complement clean nutrition when it comes to weight loss or weight maintenance.
Today, I'll discuss common mistakes with exercise and how to use exercise as a tool for overall fitness and health.
First, health and fitness are not necessarily linear. Many times fitness can be at the sacrifice of our overall health. Workouts that are high-impact or highly repetitive can improve fitness, but at the sacrifice of our joints, hormone balance, etc. So although we may be and look more fit, the health consequences can eventually rear their ugly head and cause adrenal fatigue and joint pain/dysfunction. There are far too many "fit" people who are needing joint replacements in their 40s.
However, it is possible for fitness to linearly improve health with the right focus.
For exercise to work long-term and truly improve your health AND fitness, you want to apply a minimal amount of repetition and wear-and-tear to produce maximal stimulus and adaptation.
You have to temporarily weaken the muscle fibers in order to get adaptation. An exercise that doesn't cause temporary weakness will not create adaptation. On the other hand, unnecessary force and wear-and-tear might cause fitness to rise but health to decline. It has to be a happy medium for long-term success (1).
This study shows two groups of people exercising.
Group one exercised on a bike for 30 seconds at max intensity with a four-minute rest period. They repeated this 3-5 times, on three non-consecutive days/week. Their total workout time was between 5 and 7 minutes each day.
Group two exercised at moderate intensity for 90-120 minutes on three non-consecutive days/week.
Both of these groups had the same outcomes at the end of the 12 weeks, indicating that the longer time exercising wasn't necessary to achieve results. In addition, the extra wear-and-tear from excessive repetition in the longer exercise group would probably cause orthopedic overuse injuries after a short amount of time.
Steady-state cardio is any activity you could sustain for an extended period (45 minutes or longer). Jogging, walking, the elliptical, and biking are examples.
A molecule called glycogen is stored in your muscles to use during intense muscular effort. If that glycogen is never emptied because muscular effort is never peaked, the glycogen stores begin to fill, and glucose is converted to body fat. Simply put, exclusively focusing on steady-state cardio can actually backfire over time and cause more body fat (1).
Additionally, steady-state cardio primarily stimulates type 1 muscle fibers, which are the weakest, but slowest-fatiguing fibers. Your body prefers to use these fibers, as they expend the least amount of energy to recruit.
The problem with only stimulating your type 1 fibers is that you will not gain muscle very effectively since the type 1 fibers don't possess as much mass as type 2 fibers.
Why do we need muscle for weight loss?
Muscle is the most calorically expensive tissue in your body, meaning it burns 50-100 calories/day to keep you alive. So if you add an additional 5lb of muscle, you could be burning an additional 500 calories/day, not including your workout.
On the contrary, a jogger that isn't engaging in resistance training could lose 5lb of muscle over a period of time, dropping their resting metabolic rate (amount of calories their body burns to keep them alive) by 250-500 calories/day. You could see how this could also contribute to weight gain over time or require you to continue to restrict calorie intake.
Intensity comes from stimulating as many muscle fibers as possible within a short amount of time. This will cause temporary weakness, called inroading. This temporary weakness means you have emptied all the glycogen stores from your muscles, caused microdamage, and if enough recovery time is allotted, that muscle will grow back bigger and stronger (1).
The mistake people make is thinking that speed or acceleration (like plyometrics) causes intensity. Acceleration is not necessary to recruit the max amount of muscle fibers and can provide an unnecessary risk to health/joints.
Force is an equation where acceleration is multiplied by mass, meaning that even increasing acceleration a little can increase force significantly. Suppose you can use enough mass (resistance) and the acceleration is very slow. In that case, you can still recruit all the fibers necessary to generate intensity without unnecessarily placing force through your muscles/structures. This gets you to your goal of improving muscle while minimizing wear-and-tear (improving fitness AND health).
As I mentioned earlier, muscle is what will boost your metabolism and allow you to burn more calories while you sleep. To do this optimally, you want to stimulate both type 1 and type 2 muscle fibers in every exercise.
Type 1 muscle fibers are the slow-twitch, endurance fibers. These fibers are your body's preferred method for recruiting muscle since they are cost-efficient and don't take much energy to recruit. However, these fibers are not very strong, and stimulating these fibers won't result in much muscle gain. Type 1 fibers recover quickly (within a couple of minutes after being stimulated). (1).
If there is enough force, the type 1 fibers will tap out, and the body sequentially stimulates type 2 muscle fibers. These are also called your fast-twitch muscle fibers and are where your power lies. There are different sub-categories of these fibers (which will be discussed in the teacher training) that fire at different times. Type 2 fibers fatigue quickly, in about 2-20 seconds, and take a long time to recover (days). (1).
To optimally build muscle, recruit both of these fiber types.
The safest way to do this is to select a weight and exercise that will fatigue you after about 45-90 seconds.
Suppose you select an exercise that's too easy and can be done for much longer than that. In that case, you're probably only firing your type 1 muscle fiber types that recover quickly and don't lead to muscular gains (and you'll run into the same problem that the runners have, see above).
If you choose a weight that is too heavy and you can only do a few repetitions, you are not stimulating the type 1 fibers and jumping straight to type 2 fibers, which are recruited when your body needs power.
So in order to recruit all of the fiber types and gain muscle without sacrificing your joints, choose a moderate weight, go SLOW, and use your brain to squeeze and recruit every muscle fiber that you can.
I always cue my classes to act as if you're lifting 1000 pounds. Your brain recruits the fibers, and a heavy weight is not necessary for full recruitment. This will also mean you are placing less force through your joints but still getting the muscular benefit.
If you want to learn how to design exercise classes and teach lifting, pilates, barre, kickboxing, yoga sculpt, and more using this scientific philosophy, check out the 200-hour fitness teacher training that's starting in April! Sign-ups close on March 1st.
If you want to exercise in this way, make sure to join Levo, where we prioritize building muscle, improving fitness, AND linearly improving all-around health.
McGuff, Doug M.D., Little, John. Body By Science. Northern River Productions, 2009.