Just about, no scratch that, every client I have is on some form of this, but what is it?
MRT is actually the best way to lose weight and should be the main focus of any fat loss program, if you think of your muscular system as machinery and fat as dead weight, we know muscle weighs more than fat, but it also burns more calories than fat. When designing programs we want to use this powerful machinery to its fullest potential; traditional strength, power and hypertrophy programs are insufficient stimulus to create enough of a disturbance in your metabolism to really illicit the greatest response. Instead we want to focus on making that machinery work and in turn recover. The great thing about MRT for beginners is due to your inexperience with weightlifting you will increase your muscle mass (if you compliment this training with a high protein/low carbohydrate diet), even experienced lifters can increase muscle mass, mostly due to the intensity of these programs. The aforementioned training styles (strength, power, and hypertrophy) rely heavily on rest periods and very heavy weight whereas metabolic resistance work focuses on moderate weight, many sets (without rest) and decreased rest intervals. If you increase that hard working machinery you will shift your body toward preferential fat oxidization (via EPOC/”afterburn”).
Beginners come into the gym with poorly developed neural pathways and an inability to activate to the full extent they are capable, their muscles. They need time with less intense (in terms of volume) forms of weight training to help develop neurally, this gives them plenty of time to work off any extra body fat, before they start to build large amounts of muscle (bodybuilder programs, due to their overloading nature, confuse neural pathways by training the body in an opposing way to which it moves naturally). The great thing about being a beginner is that due to your inexperience with weightlifting, you will still increase muscle mass, it's generally within the first year of weight training that you gain the most mass.
Even experienced lifters can gain from these programs too, due to their intensity, most traditional (strength, power, hypertrophy) programs are nowhere near intense enough and a large component to gaining muscle mass is intensity.
MRT can also be corrective in nature where traditional programs generally aren't, by using an appropriate amount of weight and bodyweight the lifter gets strong enough to manipulate their own body through space which is essential as a foundation. Usually unilateral (one side at a time) exercises are used to create greater workload and energy demand which brings into play things like single leg training which is important for restoring and promoting glute health, knee stability and proper hip complex function. It can be used in conjunction with anaerobic programs (such as high intensity interval training) to help correct imbalances, further reduce fat storage on the body and stimulate muscle growth (which = increased metabolism which = decrease in fat loss, improved vitality etc).
When restricting calories, working harder and recovering all the time means your body has a tendency to go into what’s known as a catabolic state which roughly means your body is looking for energy to maintain its basal metabolic rate (base energy level to perform all functions of the body: breathing, heart rate etc). What you need to remember about your powerful machinery is that it is an abundant source of stored energy. Your body wants to use this energy because it can access it easily, if you put your body into a state of catabolism. You can do this through not following your diet (not eating high protein meals frequently), spending hours on the treadmill doing steady state cardio or by skipping your MRT. This lack of caloric intake coupled with excessive cardio and no weight training will cause your body to use less energy, which will cause it to reduce your metabolic rate which will cause your fat loss goals to stall, perhaps even reverse.
Muscle is the key component in almost all things regrading health; metabolism is increased through greater muscle mass which causes all sorts of benefits such as increased fat loss, protective effects on the body's systems and mineral storage. It creates greater surface area which helps with metabolism, hormone function (regulation thereof). As muscle is essentially protein, and many of the body's processes (hormones, enzymes etc) run via protein receptors and proteins throughout the body, it increases their effectiveness.
At the end of the day it isn’t just about metabolic work, combine this with high intensity interval training and a high protein/low carbohydrate (moderate healthy fats) diet and losing bodyfat becomes actually quite easy. Quality of life/self esteem improves, movement, postural, physiological and mental faculties will all be increased, in a very short amount of time.
Examples of MRT
Superset pairings (agonist/antagonist, i.e. - chest/back).
Alternating set (upper body/lower body, i.e. - back/legs).
Circuits (horizontal push/horizontal pull/ vertical push/vertical pull/quad dominant/ hip dominant/core, i.e.- chest/row/shoulder press/ chin-up/ squat/ leg curl/ plank).
Escalating Density Training- (superset pairings agonist/antagonist, usually, for time i.e. - Push up/Inverted Row).
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Demling R.H., DeSanti L., (2000). Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Annals of Nutrition and Metabolism. 44(1):21-9.
Hunter G.R., Byrne N.M., Sirikul B., Fernández J.R., Zuckerman P.A., Darnell B.E., Gower B.A., (2008). Resistance training conserves fat-free mass and resting energy expenditure following weight loss. Obesity (Silver Spring). (5):1045-51.
Idoate F., Ibañez J., Gorostiaga E.M., García-Unciti M., Martínez-Labari C., Izquierdo M., (2010). Weight-loss diet alone or combined with resistance training induces different regional visceral fat changes in obese women. Internationl Journal of Obesity.
Pighon A., Paquette A., Barsalani R., Chapados N.A., Rabasa-Lhoret R., Yasari S., Prud'homme D., Lavoie J.M., (2009). Resistance training attenuates fat mass regain after weight loss in ovariectomized rats. Maturitas. 64(1):52-7.