There are many different reasons that people exercise: weight loss, cardiovascular health, strength improvement, stress reduction, recreation, and more. If you are looking for recreation and stress reduction, mildly aerobic exercise such as walking, jogging or swimming can be beneficial. If you want to lose weight, the evidence is fairly clear that dietary changes have a much more significant impact than most forms of exercise. If your goal, however, is fitness–either cardiovascular fitness or strength improvement–there is no substitute for high intensity exercise. An in particular, three high intensity methods pack a special punch: slow cadence resistance training, the “inverted pyramid” technique, and interval training.
Slow cadence, high intensity resistance training. Based on the fundamental principles of Hormetism, improvement in strength requires adaptive remodeling in response to applied stress. In order to see real improvement, the stress must push the system beyond its current “comfort zone”, by the use of high intensity exercise. One of the best translations of this principle into physiological terms is the book “Body by Science”, by Doug McGuff, an emergency room physician who has extensively studied the physiological adaptations that accompany high intensity exercise.
McGuff makes a strong case that high intensity (HIT) exercise, provides in as little as 12-20 minutes a week provides benefits that cannot be achieved by hours of “aerobics” such as walking, jogging, treadmills, swimming or the like. Many will agree that resistance training will lead to improved muscular strength and help to moderate the risk of injury in running or other sports. But McGuff goes further, arguing that HIT is actually superior to aerobics for improving the cardiovascular system:
Strength training is actually the best way to train the cardiovascular system precisely because, unlike what we refer to as “aerobics”, strength training actually involves and stimulates all the components of metabolism. (BBS, p. 35)
This includes both “anaerobic” metabolism that occurs in the cytosol and “aerobic” metabolism that occurs in the mitochondria. Typical cardio routines such as treadmills and jogging fail to do this:
[L]ow intensity steady state (popularly referred to as “cardio”) activity does not tap the fast-twitch muscle fibers that possess the most glycogen. Consequently the muscles are never emptied of meaningful levels of glucose, with the result that the circulating glucose has nowhere to be stored — except as bodyfat. Moreover, the muscle cells will lose their sensitivity to insulin but become inflamed by the high levels of insulin that the body has produced to deal with the high levels of circulating glucose. The body mortars this inflammation with LDL cholesterol, which puts the low intensity exerciser at greater risk for cardiovascular problems. (BBS, pp. 31-34)
In his book, McGuff makes the case that HIT works effectively only if performed in an intense manner, just short of the point of failure, with slow movements in good form, and with appropriately long periods of recovery to stimulate growth and allow adaptation of the muscle. In Chapter 3, “The Dose-Response Relationship”, he explicitly pursues the improvement of fitness as a hormetic phenomenon:
Both a drug and an exercise act as a stimulus to the body, both require an optimal concentration, both require a dose that is not “too high” and both require an appropriate frequency. The concentration of the drug is analogous to the amount of sets performed in a given workout, and the dosing frequency is analogous to the frequency of exposure to the training stimulus. Also, just as with medicine, there exists in exercise a “narrow therapeutic window” within which the volume of exercise can act to stimulate the body to produce a positive adaptive response that is optimal.
McGuff goes on to explain how the body, when challenged with exercise, recruits muscle fibers in a fixed order, according to what is demanded. When the physical demand is low, the body will prefer to recruit the Type I or Slow Twitch muscles. It will only recruit the higher types IIA, IIAB and IIB (Fatigue Resistant, Intermediate Fatigubility and Fast Twitch or Glycolytic) fibers as the intensity of the demand increases. The fast-twitch fibers are the ones that tax the glycolytic pathways, leading to an adaptive response. But these same fast-twitch fiber fatigue easily and require the most time to recover. Try to perform an intense routine too soon after the intense exercise (which can take 4-10 days in some cases), and you will find that these muscles will not have yet properly recovered, leading to suboptimal performance. McGuff recommends that each major muscle group in rotation be subjected to a resistance exercise that takes the muscles to the point of exhaustion, using a small number of repetitions. It is at the point of near failure–where one can feel the lactic acid “burn”–that the glycolytic pathway and enzyme cascade is fully activated, leading to significant increases in muscular capacity after a requisite period of rest and recovery.
Because of the “order of recruitment”, performing high intensity exercise will also strengthen and adapt the slow twitch muscles, but the reverse is not true; sprinting will benefit your running and walking, but extensive walking will never make you a good runner. Of course, training benefits by specificity, so weight training is not sufficient to be a good athlete in any specific sport. A more appropriate routine for improving running capability is interval training, which includes periodic sprinting. This will push the muscles and metabolisim to adapt to a higher level of capability. Another advantage of shorter, more intense routines is that the chance of injury is reduced. Most injuries are overuse injuries or velocity injuries. By minimizing force and acceleration with the “slow cadence” technique, the risk of injury is minimized. The slow cadence method further ensures that muscles are truly worked and fatigued. This follows the hormetic principle of “constraint”, by using good form to focus the stress where it will provide the greatest benefit; moving weights at higher velocities (as seems to be common in most gyms) bypasses this “work” by relying upon the momentum of the weights, rather than the exertion of the muscles. In that sense, it is cheating, and the benefits will be suboptimal.
McGuff’s book is not the only program to advocate slow cadence, high intensity resistance training. Several other excellent books follow essentially the same recommendations, including Power of 10 and Slow Burn, both of which provide very practical advice on exercise. While McGuff provides perhaps the best physiological explanation, he was certainly not the first to advocate high intensity training, which originated in the 1970s with the ideas of Arthur Jones, the inventor of Nautilis weight machines. Some trace the origins of slow cadence weight training back even further, to Gustav Zander. Zander developed similar equipment and exercises the 19th century.
The inverted pyramid. I have found one additional useful refinement to slow cadence, high intensity training–a refinement which will allow you to get the most out of each training session. This is the so-called “inverted pyramid” technique described in Dr. Bernstein’s Diabetes Solution. Dr. Richard Bernstein, an M.D. and engineer who is also a Type I diabetic, was in poor health after years of following the conventional advice for a high carbohydrate diet with large insulin injections. He discovered that he could control and largely reverse his diabetes symptoms by following a strict low carbohydrate diet with much smaller insulin injections for “fine tuning”. For some of his patients, this even eliminated the need for injected insulin. Dr. Bernstein also found that insulin sensitivity could be largely restored by using high intensity anaerobic exercise such as weight training. In developing an exercise regimine, he invented the “inverted pyramid”:
Continuous anaerobic activity, as you can well imagine, is really impossible. The pain caused by lactic acid in the involved muscles becomes intolerable, and the weakness that develops with extreme exertion leaves you limp…The most productive way to perform an anaerobic exercise is to tire a particular group of muscles as quickly as possible, and keep them tired during the course of the exercise. This may sound a little strange, given that we’re all accustomed to the idea that athletes work in precisely the opposite manner–warming up slowly and building to a fast finish. That may be fine for a sprint, but we’re not talking about racing here, we’re talking about building muscle mass. By placing maximum demands on your muscles at first, you put yourself in the anaerobic (or oxygen-deprived) state right off. Then by slowly progressing to lighter weights, your force your muscles to work continuously in the anaerobic state and thereby build them…The idea is quality, not quantity, and it’s my belief that you can accomplish a more thorough and sensible workout in 15-30 minutes than you can in an hour and a half of conventional, less strenuous aerobic activity. (DS, pp. 181-184).
I have found that by using the inverted pyramid, I can triple the number of high intensity repetitions that I would normally be able to do, accelerating my progress in weight lifting. The best way to do this is to combine the slow cadence method with the inverted pyramid as follows:
- First, do one set of any given weight lifting exercise using the maximum weight that you can tolerable lift slowly (8-10 seconds per direction) for 4-8 reps. Your target muscle should be totally exhausted and unable to complete even one more rep. If you can last more than 8 reps, the weight was too light.
- Then, reduce the weight by 10-20%, and do another set of at least 4 reps – to muscle exhaustion
- Finally, reduce by another 10-20% and do a final set of 4 reps – to muscle exhaustion
By the end of this inverted pyramid your exercised muscles will be totally exhausted, but you will both reach the anaerobic state faster, and extend it for significantly longer, than almost any other possible training routine. You should be able to continue with a full course of additional exercises to exhaust different, complementary muscles. For those interested in a more intense version of the inverted pyramid, check out Martin Berkhans’ reverse pyramid protocol.
To summarize: slow cadence, high intensity training embodies four of the five principles of Hormetism: constraint, intensity, recovery and gradualism. But it leaves out an important one: simulation
Interval training. While high intensity resistance training is beneficial in improving general strength and cardiovascular fitness, it is recognized that training for performance in specific sports requires specificity — that is, the modeling of the actual type of activity involved in that sport. According to the hormetic principle of simulation, strength is most effectively built by reproducing as closely as possible the conditions in which the capacity being trained is needed.
In sports such as running, swimming, and skiing — or even in “game” sports such as tennis, soccer, and baseball — there are specific actions to be practiced where strength and endurance are advantageous. This is where interval training comes in. By varying the intensity and the specific conditions of specific athletic movements, the athlete builds up the capacity to handle challenge. So even a longer distance runner can benefit by mixing a variety of intensities and distances into training, including short, fast sprints, fast miles, and longer runs. In fact, alternating among these different paces within a single training session is ideal. It allows an alternation of stress and recovery even within a single session. And putting together a training program over several weeks will ideally combine faster, shorter runs, with slower endurance runs. The same principles apply to training other specific motions. In baseball, for example, batting practice with various pitch speeds and curves prepares the batter for the greatest variety of pitches that might come his way.
A final comment: In order to achieve fitness, it is beneficial to think of diet and exercise in a unified manner. In the case of Hormetism, this means a combined approach to reducing insulin, increasing muscle mass and strength, and doing so progressively and in an efficient manner. Many of the websites out there tend to promote either weight loss or body building, and the bodybuilding sites emphasize an unrealistic ideal of overmuscled individuals that is not accessible for most of us. If you goal is just getting stronger and getting fitter, and not looking like The Hulk, I recommend one site that puts diet and fitness things together in a compelling and refreshing way: The Fitness Blackbook. Check it out.
If this topic interests you, please comment below, or check out the Fitness Forum.