Glycogen depletion is an important component of successful aerobic and anaerobic exercise. The key is sufficient exercise intensity to deplete glycogen and, if possible, stimulate growth hormone release. Here are some details on how to benefit from this strategy.
I think that the best cardio for weight loss combines various HIIT training routines to give you all of the benefits, a strong HGH release, fatty acid release, calorie burning and glycogen depletion. Your workout should start with the …
Aerobic activities normally do not elevate growth hormone levels, even though they are healthy, unless they lead to a significant degree of glycogen depletion. Glycogen is stored in the liver and muscle, with muscle storing about 5 …
The simplest personal fitness exercise program may involve the kettlebell combination. This brief video shows you what it looks like and how you can make it part of your personal fitness system. The equipment is inexpensive, too. Take a look and see what I mean.
Emily performs a combination of the kettlebell pull, clean, clean-to-press, and swing with kettlebell instructor Richard Lehman of Compliment Fitness, NYC. Email firstname.lastname@example.org for kettlebell class information and personal training.
Real Difference Between Fast And Slow Twitch Muscles
Slow twitch muscles are the simplest to describe. They are powerful aerobically, meaning good at using oxygen. They are called slow twitch because they are slow to fatigue, not because they are slow to contract. Being slow to fatigue makes this type of muscle fiber important for endurance. These fibers recover fast after being fatigued. Slow twitch muscle fibers are useful to long distance runners and other endurance athletes.
Fast twitch muscles are more complicated, because they are classified into three subgroups. One is the Fast Oxidative fibers, which are good aerobically and are resistant to fatigue. Another type is Fast Glycolytic, which includes fibers that are more effective anaerobically (without oxygen transfer). They are the easiest to fatigue and the slowest to recover. The third type is intermediate, referred to as Fast Oxidative Glycolytic. The fast twitch muscles are so called because they fatigue fast. However, they recover slowly after being fatigued.
These are simplified descriptions of how muscle fibers are classified based on their ability to use oxygen and on the speed at which they fatigue and recover from fatigue. Slow twitch muscles actually twitch faster and recover faster from exercise than do fast twitch muscles.
Engaging Each Muscle Fiber Type
Your brain recruits muscle fibers for force rather than speed of contraction. For this reason, slow twitch muscles are the easiest fiber type to engage. They also require the least amount of energy. In fact, if you lift weights too quickly, you primarily engage your slow twitch muscles.
Slightly more energy is required to engage the Fast Oxidative muscle fibers, and still more for the Fast Oxidative Glycolytic fibers. The highest amount of energy is required to engage the Fast Glycolytic fibers.
The key for an optimum workout, therefore, is to take advantage of what physiologists call orderly recruitment. This means engaging each type of muscle fiber in sequence, from low energy and fast recovery to high energy and slow recovery. The important factors for accomplishing this in the same workout are: 1) sufficient weight for bringing on muscle failure (i.e., the point at which you can no longer lift the weight); 2) the right lifting speed for engaging all types of muscle fibers in sequence; and, 3) the total time under load (TUL) for a particular set or muscle group.
The optimum strategy for accomplishing all of the above entails a very slow lift rate and an equally slow return rate. One extra advantage of such super slow movements is that it is easier to use good form. Fast lifting leads to jerking weights rather than lifting them, which recruits some slow twitch muscles and leaves other fiber types unchallenged.
All the recommendations in this article are backed by numerous scientific studies over the past few decades. The best summary of this research is now available in a book, Body by Science, by Dr. Doug McGuff, M.D., and John Little. It is the best and most recent book on this topic. By the way, the subtitle of this book is, A Research-Based Program for Strength Training, Body Building, and Complete Fitness in 12 Minutes a Week.
On a personal note based on my experience, 12 minutes a week may even be more than you need. My own muscle building improvements have accrued very effectively on about 10 minutes a week.