By Dr. Mercola
A new study examining the difference between lifting heavy weights, as opposed to a lighter load, to the point of muscle failure, has shown that there is no difference in the way your body responds to the weight usedi.
Scientists measured both muscle volume and strength gains as part of their experiment.
According to the authors:
"In accordance with our previous acute measurements of muscle protein synthetic rates a lower load lifted to failure resulted in similar hypertrophy as a heavy load lifted to failure."
This confirms what fitness experts like Dr. Doug McGuff teaches, and what I have personally been doing for some time.
The key to increase muscle and improve fitness lies in working your muscle to fatigue, but you don't need to lift heavy weights to do so.
There is a Goldilock's zone, however, where the weight is heavy enough to bring you to fatigue within a certain amount of repetitions, but not so heavy that you cannot complete the set within a minute or two.
Principles of Super-Slow Weight Training
Dr. McGuff is a proponent of so-called super-slow weight training, which actually produces many of the same health- and fitness benefits as high-intensity interval training, which is a key aspect of my Peak Fitness program.
But instead of using a stationary bike or elliptical machine, you're lifting weights . These two forms of exercise may at first sound like complete opposites—super-slow versus high-intensity—but the combination of slowing down your lifts and lifting to failure turns it into a high-intensity exercise. Metabolically speaking, both forms are very similar to each other, because you're producing metabolic byproducts of that fatigue.
One such byproduct is lactic acid.
Whether you're doing high-intensity interval training on an elliptical or doing super-slow weight lifting, the lactic acid produced generates a cascade of metabolic adaptations that improve your muscle strength and fitness level.
One of the primary differences is that during anaerobic interval training, these metabolic adaptations occur as a side effect of the activity—I've previously discussed how these types of exercises help boost and shape muscles throughout your body—but during super-slow weight training, these adaptations are a deliberate part of the goal of the exercise, which is to momentarily bring a given muscle group into deep fatigue in order to increase the strength of that muscle—and to do so within a span of 60 to 120 seconds.
How much actual muscle mass you gain depends on your individual expression of certain genes. Your genome governs how large your muscles can become, and how responsive your muscles will be to exercise. However, regardless of how large your muscles become, your body will get stronger as a result of these types of exercises. Some people can be enormously strong without looking like Schwarzenegger, and some who are very muscular might not have great strength.
Another adaptation that occurs is the improvement of your glucose storage capability. Regardless of the increase in actual muscle mass, your glucose storage capability will increase, and that is a very important factor for overall health. And, just like high-intensity interval training, super-slow weight training promotes the production of human growth hormone (HGH), aka "the fitness hormone," which plays an important role in maintaining optimal health, fitness, and longevity. In fact, according to Dr. McGuff you only need 12 minutes of Super-Slow type strength training once a week to achieve the same growth hormone production as you would with Peak Fitness!
How to Perform Super-Slow Weight Lifting
To summarize, by aggressively working your muscle to fatigue, you stimulate muscular adaptations that improve the metabolic capability of your muscle, which causes it to increase in strength and size.
Dr. McGuff recommends using four or five basic compound movements for your exercise set. These exercises can be done using either free weights or machines. The benefit of using a quality machine is that it will allow you to focus your mind on the effort rather than your form. The following five movements are a good place to start:
- Pull-down (or alternatively chin-up)
- Chest press
- Compound row (A pulling motion in the horizontal plane)
- Overhead press
- Leg press
Next is a summary of how to perform each exercise. If you're using the appropriate amount of weight or resistance, you'll be able to perform four to eight repetitions for each exercise set. When done properly, your workout will take no more than 12 or 15 minutes.
- Begin by lifting the weight as slowly and gradually as you can. The first inch should take about two seconds. Since you're depriving yourself of all the momentum of snatching the weight upward, it will be very difficult to complete the full movement in less than 7-10 seconds.
This super-slow movement allows your muscle, at the microscopic level, to access the maximum number of cross-bridges between the protein filaments that produce movement in the muscle. When pushing, stop about 10 to 15 degrees before your limb is fully straightened; smoothly reverse direction
- Slowly lower the weight back down
- Repeat until exhaustion. Once you reach exhaustion, don't try to heave or jerk the weight to get one last repetition in. Instead, just keep trying to produce the movement, even if it's not 'going' anywhere, for another five seconds or so
- Immediately switch to the next exercise for the next target muscle group and repeat the first three steps
When Pushing to the Point of Failure is Just Too Much
For those of you who feel that pushing yourself to the point of muscle failure is just too much sometimes, there's another study out that explains that too. In this study, researchers found that the old adage, "it's all in your head" is true in that, typically, it's your mind that limits you from pushing to failure, not your bodyii. It's taken more than a century for scientists to figure this out, and to explain how your brain works in conjunction with your body to ensure that you stop exercising before physical harm develops—a key to overall improvement in your exercise routine.
The study, which is aptly titled: "Fatigue is a Brain-Derived Emotion that Regulates the Exercise Behavior to Ensure the Protection of Whole Body Homeostasis," explains that the fatigue you may experience when exercising vigorously is a mental or emotional regulator mechanism designed to protect your body from excessive harm. It may sound strange, but the explanation they offer is actually quite sensible. The authors write:
"An influential book written by A. Mosso in the late nineteenth century proposed that fatigue that "at first sight might appear an imperfection of our body, is on the contrary one of its most marvelous perfections. The fatigue increasing more rapidly than the amount of work done saves us from the injury which lesser sensibility would involve for the organism" so that "muscular fatigue also is at bottom an exhaustion of the nervous system."
It has taken more than a century to confirm Mosso's idea that both the brain and the muscles alter their function during exercise and that fatigue is predominantly an emotion, part of a complex regulation, the goal of which is to protect the body from harm... [T]he CNS [central nervous system] regulates exercise specifically to insure that each exercise bout terminates whilst homeostasis is retained in all bodily systems." [Emphasis mine.]
Furthermore, the idea that your athletic performance is based purely on your body's physiological and metabolic responses appears to be false, according to this research, because "subconscious and conscious mental decisions made by winners and losers, in both training and competition, are the ultimate determinants of both fatigue and athletic performance."
The Importance of Recovery
The idea that fatigue is an important regulatory function to maintain physical homeostasis makes the advice to make sure you fully recover between workouts even more important. This recently became a great learning experience for me.
This is a vital area of exercise and one that obsessive-compulsives like me frequently have problems with. It took me over 40 years to realize that I was working out too hard and needed to integrate more recovery into my exercise program. Obviously this is not a problem for most people that don't exercise enough but for disciplined overachievers, this is a common misunderstanding.
I'd been doing high-intensity Peak Fitness exercises three times a week for about a year along with three one-hour strength training sessions a week when I began feeling fatigued between sessions. After my interview with Dr. McGuff, I realized I was probably pushing myself too hard and not allowing myself enough recovery time.
So when should you back down on your exercise?
An important piece of information gleaned from Dr. McGuff is that as long as your intensity is high enough, you can cut back on the frequency of the exercise without diminishing the results. In fact, if the intensity is really high, the frequency may need to be reduced, in order to continue improving.
"For any interval increase in intensity, there has to be a very disproportionate decrease in frequency for it to continue to be productive," he explains.
For example, as a weak beginner, you can exercise three times a week and not put much stress on your system. But once your strength and endurance improves, each exercise session is placing an increasingly greater amount of stress on your body (as long as you keep pushing yourself to the max). At that point, you would be wise to reduce the frequency of your sessions to give your body enough time to recover in between.
According to Dr. McGuff, once you're fit, you don't need the frequent spurts of growth hormone production. At that point, recovery takes precedence as being more important, and your recovery period could be anywhere from three to seven days. In fact, he strongly recommends NOT exercising too frequently once you are in fit condition, in order to avoid over-taxing your adrenals.
Super-Slow Weight Training Automatically Decreases Risk of Injury
Since we're discussing your body's innate intelligence to prevent you from injuring yourself, by making you feel fatigued, it's worth mentioning that super-slow weight training is a much safer form of exercise than regular strength training. The slow movement actively prevents you from accidentally harming your joints or suffering repetitive use injury, as the forces are dramatically reduced.