What is it?
Metabolic resistance training combines the benefits of traditional aerobic exercise—think running, rowing, spinning, etc with the other spectrum of the fitness world: weight training. In short, metabolic resistance training involves a cardiopulmonary response (much like one you would get from running around the block) from a weight training routine. It is designed to maximize caloric burn and increase metabolic rate during and after the work out.
What are the benefits?
While metabolic resistance training is not technically aerobic, it does provide an increased cardiovascular capacity. In fact, one study found that the increase in VO2 max was greater in subjects that performed a high intensity metabolic resistance-training program than subjects who performed a solely aerobic exercise program (Esfarjani, 2007).
Additionally, metabolic resistance training burns a TON of calories! There are two main methods by which MRT burns calories. The first method is through calories burned during the exercise session. The average estimate for caloric burn during an MRT workout is around 500 calories. This is pretty standard and comparable to an aerobic based workout as well. The second method is called Excess Postexercise Oxygen Consumption, or oxygen consumed to bring various physiological variables back to homeostasis, or resting levels. This period can last for around 72 hours after the workout is stopped, and can amount to an additional 300 calories OR MORE burned (Heden et al., 2011). This is what gives MRT an advantage over both traditional cardio exercise and traditional weight training.
Lastly, metabolic resistance training provides a hormonal response that helps to liberate fat from the body so it can be used as fuel. One such hormonal group is catecholamines. You may know these as adrenaline, epinephrine, and cortisol. This hormonal group helps with lipolysis, or the freeing of adipose (fat) cells to be used by the body as fuel. One study found that adrenaline levels in the blood were elevated after a resistance-training program (Pullinen et al., 2000). Additionally, this response is highly correlated with both the magnitude and the duration of the Excess Postexercise Oxygen Consumption period. Increased human growth hormone levels were also found post metabolic resistance training period. Growth hormone has both anabolic (muscle building) and catabolic (fat burning) properties. Growth hormone facilitates lipolysis, but also increases the sensitivity of the fat cells to the catecholamines.
What can I expect in an MRT session?
You can expect to use large muscle groups, and multiple muscle groups at one time. Many MRT programs involve both the lower body and the upper body at once, usually with some degree of core involved as well. A good example of this is a thruster, which is a squat to overhead press. You will use the quads, glutes, hamstrings, and shoulders all at once while simultaneously stabilizing through the core. The more muscle groups used at once, the higher caloric burn.
You can expect a very high intensity. While doing a metabolic resistance-training workout, you should feel breathless and you should be sweating. Most metabolic resistance training programs involve back-to-back exercises using opposite muscle groups, to cut down on rest time and keep the heart rate high. Rest time is typically no more than 30 seconds. Training at near maximal levels of effort increases calories burned during and after the workout (Scott et al, 2011).
Sample exercises include: Clean and Press, Kettlebell swing. Thrusters, Squats, Deadlift, Pull-ups, Lunge-bicep curl-Overhead press, Man Makers, etc.
Esfarjani, Fahimeh, and Paul B. Laursen. “Manipulating High-intensity Interval Training: Effects on V˙O2 max, the Lactate Threshold and 3000m Running Performance in Moderately Trained Males.” Journal of Science and Medicine in Sport 10.1 (2007): 27-35. 28 July 2006. Web.
Schoenfeld, Brad, CSCS. “Metabolic Resistance Training: Strategies to Optimize Fat Loss and Enhance Muscular Adaptations.” NSCA.com. N.p., 12 June 2012. Web. <http://www.nsca.com/uploadedFiles/NSCA/Resources/Documents/PowerPoint/Events/July%2013%203pm%20Schoenfeld(1).pdf>.
Heden T, Lox C, Rose P, Reid S, Kirk EP. One‐set resistance training elevates energy expenditure for 72 h similar to three sets. Eur J Appl Physiol. 2011 Mar;111(3):477‐84
Pullinen, Teemu, Pirkko Huttunen, and Paavo V. Komi. “Plasma Catecholamine Responses and Neural Adaptation during Short-term Resistance Training.” European Journal of Applied Physiology 82.1-2 (2000): 68-75. Print.
Scott CB, Leighton BH, Ahearn KJ, McManus JJ. Aerobic, anaerobic, and excess postexercise oxygen consumption energy expenditure of muscular endurance and strength: 1‐set of bench press to muscular fatigue. J Strength Cond Res. 2011 Apr;25(4):903‐8
Pritzlaff CJ, Wideman L, Blumer J, Jensen M, Abbott RD, Gaesser GA, Veldhuis JD, Weltman A. Catecholamine release, growth hormone secretion, and energy expenditure during exercise vs. recovery in men. J Appl Physiol. 2000 Sep;89(3) 937-46.