With all the different training styles to choose from, interval style, or "metabolic" training programs are becoming increasingly popular. These workouts are fashioned circuit style, with little to no rest in between exercises to accomplish a much larger calorie expenditure, in much less time than traditional body part splits. Most metabolic workouts work the entire body or focus on specific planes of motion within a single workout. While I personally use this style of training a few times a week, here are a few very beneficial "rules" that should be followed to ensure you are gaining the most out of your routine.

1) Wear a heart rate monitor-- the effectiveness of metabolic workouts is in the calorie burn. Until you learn instinctively what zone your body is in during training, it is wise to track your heart rate after each set or two to ensure you are keeping your heart rate high enough during the work portion and also low enough to ensure some recovery between rounds.

2) Be sure your diet supports this style of training, especially where carbs are concerned.  Depending on what your caloric intake is (mild-severe deficit) if you are restricting carbohydrate sources with a goal of fat loss, it is IMPERATIVE you take in just enough to support proper blood sugar regulation, while still allowing the body to tap into fat stores. This is where it gets quite complicated biochemically, but the bottom line is- high intensity training uses mostly GLUCOSE as a fuel source. Training at this level of intensity on low carbs can have disastrous results if you ignore this important rule!  The body will create glucose from protein and even your muscles if need be. Over time, exercising under these conditions will lead to overtraining syndrome and a complete deregulation of your endocrine and metabolic systems. You will know when this is happening when you start to experience frequent blood sugar crashes, anxiety, chronic fatigue, restless sleep, achy joints, or uncontrollable sweet cravings. This is a clear sign that your diet needs to include more carbs. My best advice is to aim for around 1 gram per pound of bodyweight (this is on the low end) and try "cycling" your intake by lowering your carbohydrates on non-training days (while increasing healthy fats)  and slightly increasing on the days you train. You will want to experiment with this to find the "threshold" that keeps all systems running smoothly.

3) Keep workouts intense but BRIEF-around 45 minutes. Again, this is relative to your caloric intake but generally, the bigger the calorie deficit, the shorter your workout should be. You are playing a balancing act of stress and fat burning hormones here so there is a fine line between what makes metabolic training beneficial or detrimental to your health! Any session that lasts longer than around 45-50 minutes appears to have a negative effect on the secretion of human growth hormone and testosterone in both men and women. Rising cortisol levels begin to cause some major damage at this point as well. (That is an article in itself!) Case in point- more is NOT better!  

Metabolic training CAN be a very useful tool in your body-sculpting arsenal. Used wisely, it can turn your body into a muscle building, fat burning machine!  Just be mindful of the relationship between proper program design and your nutrition and you will probably find it is the most efficient means of creating the body that you want without having to live in the gym or on the treadmill! Here is a great full body metabolic conditioning workout that can be done two times per week or on days you are crunched for time. Use a quick pace and perform each exercise consecutively in each round with little rest in between. Rest one minute in between sets and between the two rounds. All of these exercises can be found on YouTube.

(Round 1)

DB Push Press x 15

2 Point DB Rows (unsupported) x 15 each arm

Mountain Climbers x 25-50

T-Stab Pushups

REST 1 min.

(Round 2)

Stiff Leg DB Deadlifts x 15

Plank Pull-Ins with DB x 15 each side

Single Arm DB Snatch x 15 each side

Alternating Lunge Jumps x 20

Tana Gabrielle is a Bodybuilding.com Team Athlete/ National Level Physique Competitor and Fitness Model. She is currently a student at The Institute for Integrative Nutrition studying Holistic Health. 

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