METABOLIC EFFECT SHORTS:

Philosophy, Principles, Science, Speculations

Jade Teta ND, CSCS Keoni Teta ND, LAc, CSCS;

 

Healthcare providers need new approaches to exercise prescription for those who are motivated and able to participate. They should also be skeptical of quick fitness claims:

Exercise is losing credibility among the inactive public. The current environment of exercise prescription is rooted in low intensity, single mode, and calorie burning paradigms. This approach is successful for some, yet fails the vast majority. Health-care practitioners using current exercise recommendations know the limitations of this system. Short duration, high intensity exercise tailored to the individual and responsive to their goals offers a clear departure from current models.  Those frustrated by cook book exercise prescription and desiring real transformation need new and better approaches. There is a strong need for healthcare providers, trainers, and gym managers to incorporate new paradigms in exercise and weight loss.

 

Current prescriptive blueprints cater to the masses and the least common denominator by making recommendations based mainly on safety and convenience. While these are important considerations, they ignore participant individuality. This creates a situation of limited progress for motivated and capable participants desiring real transformation.  A quick glance in any large gym will show trainers guiding clients, with varied needs, through programs modeled after drug enhanced bodybuilders and fitness gurus. Bodybuilding workouts may deliver in developing muscle size, but are frequently prescribed indiscriminately to people seeking benefits of exercise. Studio gyms, while offering individual attention, usually use a “one size fits all” approach and are prone to gimmicks. Gyms making claims of “magical protocols” that provide superior results in less than half an hour 2 times a week, dilute exercise credibility and foster skepticism. It is important to be realistic with regards to discipline in exercise and avoid such misleading claims. ³⁴ This underscores the need for health practitioners, trainers, and gym managers to be more active and discerning in exercise prescriptions.

 

 

Calorie Burning and Steady State Cardio models need some re-thinking:

Weight loss prescriptions should not focus exclusively on calorie burning. Steady state or “in the zone” training, keeps people in a prescribed heart rate range to burn fat calories during exercise. This type of training may burn calories during the workout, but it provides little metabolic effect after the workout.³² This is a mistake made by many in the health and fitness world. Higher intensity activity above heart rate zones provides superior benefit when it comes to weight loss. ^{30, 31}

 

High intensity interval training of short duration should be the aerobic exercise of choice. Unlike steady state, in the zone training, interval exercise will burn more calories during and after exercise. ^9,10,30-32 Several studies show interval training to be superior to standard cardiovascular prescriptions. Because of the increased work involved, significant calories can be burned in a very short time. Surprisingly, this may be the optimal way to bolster fitness as well. Japanese researchers have shown very short, high intensity exercise to be most beneficial in improving cardio-respiratory fitness. ³³ This makes vigorous interval training especially useful to a time starved population averse to exercise.

 

Low intensity activities may burn more relative amounts of fat during exercise, but high intensity activity burns more absolute fat, and provides fat burning effects after the workout. ^{22, 27} Too explain, if exercise at a low intensity burns 100 calories and 70% are burned as fat, then that activity will have burned 70 units of fat. However, if the exercise intensity is increased so that 200 calories are burned but only 50% are used as fat, then 100 units of fat are used. Therefore, high intensity exercise burns a smaller proportion of fat during activity, but makes up for this with a much larger caloric burn overall. Coupled with greater post exercise calorie consumption, high intensity exercise further exceeds its lower intensity counterpart. ^{22, 27, 30-32}

 

Exercise Prescriptions should be results driven and not prescription driven

Effective prescriptions should be results driven at their core. Standard exercise recommendations make prescriptions and then predict results based on averages. In order to keep results progressing, a more intuitive and individualized approach is needed. This can be addressed by allowing results to drive the prescription instead of the reverse. Weight, body composition and circumference should be tracked weekly or biweekly. If fat loss is not occurring, than change of prescription parameters is necessary. Manipulation of exercise mode, timing, consistency, frequency, intensity, and duration allows directed individualization for continued results. More liberal use of this model will combat poor results, foster more realistic expectations among participants, and promote quick results.

 

Fitness, Function, and Form: The 3F’s

The first thing needed with exercise recommendations is a plan. In order for exercise to be effective, it is important to determine a client’s goal set. The aim of exercise participants usually falls into one of the three groups described here as fitness, function, form. This phrase acknowledges a simple truth of strength and conditioning: athletes do not train to look good, but instead, “looking good” is a natural outcome of their training regimes. Strength and conditioning coaches will train their athletes for fitness first developing attributes of strength, endurance, flexibility, and speed. These attributes are then combined to elicit the more functional aspects of athleticism; power, balance, and coordination. In this way, fitness leads to increased function. Once the athletic framework is built, form (optimal body shape) follows function. This should provoke those who prescribe exercise and exercise facilitators to put more emphasis on fitness and begin to incorporate more athletic conditioning regimes into practice with the general public.

 

To explain this idea further, fitness can be further expanded to describe exercise directed at improving cellular oxygen metabolism, cardio-respiratory efficiency, muscle endurance, flexibility, and other health measures. Functional exercise describes exercise designed to improve body mechanics such as balance, coordination, strength, agility and speed, but it can also denote improvements in function of hormonal signaling, organ function, and cellular metabolism. This explains how developing fitness parameters improves things like insulin sensitivity, lowers stress hormones, and improves heart, lung and liver function. Exercise influences all aspects of the body facilitating changes in neuro-muscular signaling, bone metabolism, and changes in muscle fiber type and size. Function is usually thought of in terms of athletes. However, functional development is applicable to the general population as well. The diseases of osteoporosis and sarcopenia found in the aging, benefit immensely from improved function. ^7,8,44 The third factor, Form, encompasses those who desire to change the “form” or shape of the body. An example would be achieving ideal body composition. This would include both fat loss and muscle gain. Weight loss is a complex process of changing “form” that is successfully impacted by exercise.^9,23. These elements play a strong role in many areas of disease prevention and treatment.

 

Prescriptive exercise should be based on research and directed to its participants. Integration becomes an important issue in program design.  Considerations should first focus on what the client wants and needs. The workout should center on that directive, while integrating other parameters for full benefit.  For example, a participant desiring weight loss may engage in a fast paced, multiple exercise program that enhances calorie burning during and after activity.^23,29 The same program would integrate whole body movements that develop balance, coordination and provide a strong cardio-respiratory stimulus.^23,29 In this way, Form is addressed through multiple mechanisms, but not at the expense of Function and Fitness. Athletic training represents the closest model to this approach. Athletes require multiple skill sets highly geared toward Function. The performance of these skills also requires extremes in Fitness and ideals in Form. Coaches train athletes specifically to match these demands. With this in mind, the average client of the industrialized world can be thought of as an “urban athlete” and prescribed exercise accordingly. Increased muscle mass without the benefit of improved balance, coordination, power, and endurance is not beneficial. By training all clients as athletes, optimal health can be approached through full development of the 3 Fs.

 

Resistance Training excels at fat loss

Exercise for weight loss should incorporate resistance training. It is a little known fact, but standard cardiovascular exercise may not be the most effective means of losing weight. ^1,2,4-6 A large meta-analysis of aerobic fitness’ impact on weight loss shows surprising results. ¹ This review of hundreds of studies over 25 years shows aerobic exercise provides only a 2 pound weight loss advantage over diet alone. ¹ When dieters are compared to the aerobically active in other studies, the differences in weight loss are negligible. ^3,6 Despite this scientific evidence, aerobic exercise is still viewed by many as the gold standard for weight loss. On the contrary, resistance training shows pronounced effects on weight loss. ^4,5,9 Exercisers using resistance training combined with aerobic activities lose more weight and lose little to no muscle. ^4,9,24

 

Resistance training provides the greatest advantage with improving body composition and if done correctly provides aerobic benefit. Heart rate responses well into the eighty percent range of max heart rate can be sustained with directed resistance protocols. This is a fact any strength or athletic coach will attest to, and can be confirmed by doing three heavy sets of barbell squats with little rest between. The fact that even some exercise experts are not aware of this highlights the need for more practical experience among people teaching and prescribing exercise programs. 

 

There is a difference between attaining ideal body composition and maintaining it

Prescriptions for weight loss need to distinguish between attaining weight loss and maintaining weight loss. Resistance training provides strong benefit in attaining weight loss, while aerobic activity bolsters weight maintenance. ^23,45 It is extremely important to remember nutrition’s role in this equation. Exercisers may do best with personalized and metabolically directed diet advice rather than generalized programs or fad diets. ⁴⁹ Behavioral modification is also important, and it too should be based on proven methods. The unique challenges of achieving and sustaining weight loss should be addressed in any exercise prescription focused on body form

 

Prescriptions for form and the hormonal Metabolic Effect:

Training for optimal body form has become a national obsession. The primary concern in this area is weight loss. Despite the preoccupation of client’s and health-care practitioners toward weight loss, optimal body composition is a more useful goal. The idea is to facilitate reduction of body fat while minimizing muscle loss. The zealous pursuit of calorie burning has created misunderstanding in weight management. Prescriptions that modulate hormonal effects will burn more calories during activity and provide greater caloric benefit after exercise. ¹¹ This increased energy use after a proper workout is referred to as excess post-exercise oxygen consumption, or EPOC. This is a measure of how much oxygen the body consumes after a workout has expired. An example of EPOC in the acute sense is climbing a steep flight of stairs. While walking up the stairs breathing is labored, but it is not until after reaching the top that respiration becomes most difficult. The body does this to recover the “debt” of oxygen created during activity. Since the amount of oxygen consumed is directly correlated to how much fat is burned, increased EPOC can be an exercisers best friend.  Vigorous workouts focusing on resistance training may create hormonal responses that can elevate EPOC for days. ²³

 

The idea of hormonal influences on calorie burning is a novel one.  Exercise of sufficient intensity elevates stress hormones like adrenaline and nor-adrenaline. Lactic acid buildup may be the trigger allowing these powerful metabolic stimulants to peak. ^40-42 EPOC is correlated with lactic acid response to exercise and catecholamine release. ^40-42,48 Catecholamines are potent fat burners by stimulating beta receptors, the equivalent of a fat burning gas peddle.⁴⁷ In response to demanding intensity, cortisol, growth hormone and testosterone are part of the cascade. This finely orchestrated hormonal response creates the perfect scenario for fat burning and muscle building during and after the workout. It is important to point out, the rise in cortisol many practitioners fear is only a problem when it is unopposed by growth hormone and testosterone.^10,13  Testosterone and growth hormone are strong fat burning hormones in their own right, and they block cortisol’s breakdown of muscle and storage of abdominal fat. ^10,13  Long duration cardiovascular exercise allows cortisol to peak unopposed, and may explain why standard aerobic prescriptions are not as effective for optimal body composition. ¹⁶  It may be the duration of aerobic exercise and not the intensity that is most detrimental in terms of cortisol.²⁸ Short duration, vigorous resistance training provides the most beneficial hormone response. However, high intensity interval training  may be the superior aerobic exercise with similar hormonal effects to resistance training. ^14,30,31

 

Application- Monitoring Heart Rate (HR) and Ratings of Perceived Exertion (RPE):

The practical application of the high intensity short duration workout manifests in a high intensity program centered on resistance training. Rating of perceived exertion, or RPE, and heart rate monitoring provide immediate feedback of intensity while maintaining safety.  A simple alternative to the Borg RPE scale is shown in table 1 below. Participants will want to keep their RPE at 6 or 7 throughout the workout with frequent spikes up to 8, 9, or even 10.  Resting until a return of RPE equal to 7 is a good guide. Concurrently, percent of heart rate max should be at or above 74% with frequent bouts between 85% and 100%. ³⁸  An acute EPOC response can be seen on a heart rate monitor by an immediate spike then fall in heart rate on completion of an exercise. Participants and trainers should always defer to RPE numbers for safety as heart rate equations can sometimes over estimate in the young or under predict actual max heart rate in the old.  The equation 208-(.7x age) is more accurate than the older 220-age. ³⁹

 

Table 1. Exertion rates and intensity descriptions

RPE	Intensity descriptions
1	Resting
2	Very light: - Not out of breath - No sense of muscle strain
3	Light: - Active with no real sense of exertion - Lifting light weight causing no burning or difficulty
4	Moderate: - Slightly out of breath - Aware of slight muscle discomfort
5	Moderately uncomfortable: - Aware of exercise, can talk with out difficulty - Notice muscle strain with no difficulty lifting weight
6	Uncomfortable: - Aware of activity; getting difficult to talk - Slight muscle discomfort, weight becoming difficult to lift
7	Moderately Difficult: - No longer want to talk; breathing becoming labored - Muscles begin burning, weight difficult to lift
8	Difficult: - Can no longer talk, heavy breathing - Barely able to lift weight and/or intense muscle burn making Lifting difficult
9	Very Difficult: - Near max effort, breathing rapid, must focus all Attention - No longer able to lift weight due to mechanical and/or metabolic failure
10	Max effort: - All out exertion, can not continue exercise much Longer - Muscles have reached full mechanical and/or metabolic fatigue Another rep is not possible

 

Full body, multiple joint, hybrid exercises, and supersets:

 

Full body multi-joint exercises should be used in place of isolated movements to increase muscle recruitment. The amount of contracting muscle used during an exercise is referred to here as total body contraction, or TBC. Multi-joint movements use many muscle groups; provide increased calorie burning, enhance EPOC, and provoke gains in the 3 Fs. ^7,8,23,50 Hybrid exercises, involving two separate movements superimposed on each other, are another form of multi-joint exercise that provide beneficial effects through increased TBC. ⁵⁰ Hybrids are complex examples of supersets and compound sets. Supersets and compound sets refer to exercises done back to back for different muscle groups and the same muscle group respectively. Doing back to back exercises without rest has a beneficial effect on EPOC. ²⁹

 

Weight, sets, and reps:

Weights should be heavy enough to elicit gains in muscle, yet light enough to maintain form. Depending on the exercise, weights representing 65%-80% of a 1 rep max should be used. Sets and repetitions should represent the intent to build muscle and burn fat. A repetition range of 8-12 with multiple sets of three to four will maximize muscular development. ^14,15 Contrary to the belief of some, multiple sets are superior to single sets. Single sets and super slow protocols are not optimal for those seeking Form, Function, and Fitness. ⁴⁶ Rest periods should be kept to a minimum with a focus on keeping the body moving. ³⁵ Active rests like pacing are more useful than complete cessation of activity. This technique helps to clear metabolic waste, prevent venous pooling, and keep the muscles warm. RPE and heart rate monitoring will help individualize work and rest intervals within a single session and from workout to workout.

 

Final Thoughts:

The current environment in exercise prescription for weight loss is still rooted in the low intensity, single mode, and calorie burning paradigms. This approach is successful for some, yet fails the vast majority. New models for exercise fitness are needed for the growing epidemic of overweight, obesity, and chronic disease. Short duration, high intensity exercise tailored to the individual and responsive to their goals offers a clear departure from current models.  Those frustrated by cook book exercise prescription and desiring real transformation need new and better approaches for overweight and obesity. There is a strong need for healthcare providers, trainers, and gym managers to incorporate new paradigms in exercise and weight loss.

 

References:

Metabolic Effect Shorts
Philosophy, Principles, Science, Speculations

Hormonal Weight Loss:
Is there such a thing as the “Metabolic Effect?”

Exercise is Medicine:
The anti-inflammatory effects of high intensity exercise