Written by Funk Roberts
If you’ve been training hard and not seeing the results you were hoping for, tweaking your training routine might be all your body needs. For your body to progress, grow, and adapt, it needs a continuous challenge. That doesn’t mean challenging it daily with the same routine—it means turning up the heat on your workout and changing variables to challenge your body in ways it’s never been challenged. It’s called the law of progressive overload, and it’s how you can get your dream body.
There are plenty of ways to work overload into your training program, but none are as effective as HIIT with weights.
If you’ve never ventured into high-intensity training, you’re about to have your eyes opened to how amazing your results can be. It fires up your muscles and metabolism to burn calories, melt fat, and build muscle simultaneously.
What is metabolic resistance training?
Metabolic resistance training—you’ve likely never heard about it, but it’s about to become your new favorite training style. Usually referred to as MRT, metabolic resistance training is a training strategy that combines high-intensity exercises with resistance (weights) to build lean muscle, torch body fat, and improve overall physical fitness.
There’s a lot of research on how effective HIIT is for melting body fat and burning calories, but when you’re combining all-out max effort with solid compound muscle-building movements, you’re raising your metabolism to burn calories, increase your lactate threshold, boost muscle growth, and enhance your body’s ability to adapt.
Yet here’s the thing—no single workout constitutes MRT. It’s an umbrella term that describes any form of intense, cardiovascular and muscular training. We’re talking about combining supersets, circuits, and bodyweight movements that elevate your heartrate and fire up your muscles. MRT is so effective for fat loss because you’re not only boosting your metabolism during your workout to burn calories and fat, but it stays elevated after thanks to the EPOC effect to continue the calorie and fat burn even after you’ve stopped training. It blurs the lines between conventional weight training and cardio to form a style of training that’s substantially more effective than either alone.
The benefits of using dumbbells
You can’t argue that dumbbells are effective. Whether working in the high-rep low weight range or reversing it to the low-rep high weight range, it’s easy to build muscle with dumbbells. Aside from kettlebells, dumbbells are some of the best free weights you can use for overall functionality and performance. Here’s why:
Better stabilization and muscle activation
Using a machine is great if you’re looking to overload your muscles, but if you’re looking to go beyond fatigue, you can’t get much better than a good ol’ set of dumbbells. Compared to machines and even barbells, dumbbells require more stabilization to perform the same exercise solely because of where the weight sits on a dumbbell in relation to where your hand is. When more stabilization is required, you’re activating more muscle fibres and potentially doing more damage (more damage = more muscle growth). With any sort of free weight, the load isn’t stable—you tip it the wrong way, and the load can move anywhere it pleases. That said, your stabilizer muscles are there to prevent that from happening; they ensure the load is controlled and moving efficiently. This doesn't happen when using machines because the movement pathways are fixed.
Poor stabilizer recruitment means the body has to accommodate during movements by generating more momentum or altering movement patterns to overcome a lack of stabilization. Because of this, your injury risk increases and you ingrain poor movement patterns, neither of which we want. Plus, strong stabilizers allow you to lift greater loads. More stable structures can generate higher levels of force and, therefore, more power.
Reduces strength imbalances
Machines and barbells are effective for increasing strength, but there’s one downside to only sticking to preset movement pathways where both arms are working together: strength imbalances. Have you ever done a bench press only to notice that one arm is significantly stronger than the other? If you’re always using machines and barbells, it can be difficult to see strength imbalances developing because another muscle group picks up the slack. However, you can’t do that with dumbbells—they force your limbs to work unilaterally, which helps build strength in weaker muscles to avoid compensation and improper movement patterns.
More options to increase the intensity
Whether you’re firing up your muscles with drop sets, rest-pause, or whatever other technique you fancy, you can increase the challenge a lot more with dumbbells than you can with barbells and machines—it’s easy to rack-and-run. Plus, there are specific exercises you can do with dumbbells that you just can’t with barbells or machines.
Better range of motion
Machines, and barbells, to some degree, work on a pre-set movement pathway that doesn't allow for a full range of motion; the machine can only be extended so far and you can only move your arms a set degree with a barbell in hand. However, with dumbbells, you can move through a larger range of motion and force your body to adapt and work harder to overload the muscles and build strength.
Freedom of movement
Similar to what we just mentioned, a barbell or machine locks your body in a fixed position and a fixed range of motion, but with dumbbells, you have complete freedom of movement—there is no fixed position or range of motion to move through. There’s a lot more choice in how you move with dumbbells that you can’t get from other types of weights. If you’re trying to target a specific muscle more, change the movement pattern slightly to target it; if you’re experiencing pain on a conventional lift, rotate internally, externally, lift, or lower the weight to find a comfortable movement path that’s pain-free.
Why metabolic training works
You may think that MRT is no different than doing an intense circuit round or increasing the intensity of your lifts to get your heartrate going a bit—but it is. MRT blends strength training and interval training; high-intensity interval training elevates heartrate, calorie burn, and excess post-exercise oxygen consumption (EPOC), while strength training increases muscle growth and strength. When you combine the two, your body burns calories long after you’ve stopped working out. Essentially, metabolic resistance training increases exercise's metabolic “cost” by maximizing your body’s ability to adapt to change.
Let me explain how EPOC works. Think of it this way—your body is a car. When you take your car out for a drive, the engine heats up while it’s working, but the engine remains hot for a little while after you’ve parked. Your body works much the same. When you’re doing an intense training session, you’ll feel your body temperature rise, but when you stop working out, it doesn’t immediately fall back to its pre-workout temperature—it takes some time. During this “cool off” period, your body still burns calories while it returns to homeostasis (balance). That’s the beauty of MRT—it ignites your body’s metabolism after training to continue working even when you’re not. So, how does MRT support fat burning and muscle gain?
High-intensity workouts
HIIT is hard—if you’ve ever tried it, you can attest to the lung and muscle burn that happens when you’re going hard with minimal rest, but try adding a pair of dumbbells and see how hard it is then. MRT is by no means easy, but you get results. These workouts push your body to its limits and challenge you in ways you’ve never been challenged, using heavy loads or removing the load and increasing the speed to force your body to adapt. Higher intensity workouts require greater metabolic demand, which translates directly into better results. With MRT, you don’t need conventional cardio—it’s exhausting and ineffective. Scrap spending hours on the treadmill for a quick and dirty high-intensity workout that will get you results.
Compound full-body movements
Isolation exercises are effective if you’re looking to build muscle, but they’re not great if you want to burn fat—nothing compares to compound exercises to do both. Muscle is metabolically active tissue, and an exercise's metabolic cost (calorie burn) is directly related to the number of muscles working; more muscles working means more energy is required to fuel them, and more calories are burned.
5 Benefits of metabolic resistance training
So, why do metabolic resistance training? Here are a few reasons.
Burns more calories
If you want to burn calories, most people will jump on a treadmill, elliptical or bicycle for hours, sweat their faces off, and not see results. While conventional cardio exercises will burn calories while you’re working, calorie burn stops when you stop, but the other problem with these exercises is that unless you’re doing intervals, you’re working at a constant pace that doesn’t challenge your body.
Steady-state cardio is what most people choose to increase energy expenditure, but if your goal is to burn calories and fat in the least amount of time, ramping up your intensity is how to do it—and MRT is what reigns king. Ample studies show that high-intensity training combined with resistance training is more effective for burning calories than the same amount of time spent doing steady-state exercise. Plus, intervals offer more significant benefits for heart rate, oxygen capacity, and blood lactate concentration.
Boosts metabolic rate (EPOC + afterburn)
I mentioned EPOC before and a bit about how it works, but it’s one of the big advantages for HIIT over all other forms of exercise. Essentially, EPOC refers to the amount of oxygen your body requires to restore normal physiological and metabolic function (i.e. return to homeostasis)—and this is what explains how your body can still burn calories even after you’ve stopped exercising.
ATP is the primary fuel that supports intense physical activity and it’s produced with oxygen via aerobic pathways or without oxygen via anaerobic pathways. At the start of exercise, anaerobic pathways and stored ATP fuel your workout. Once you hit a steady state of oxygen consumption, aerobic energy pathways cannot meet the demands required to support training, which means there’s an increased demand for anaerobic generation of ATP. This switching of pathways enhances the EPOC effect.
Now here’s the thing with HIIT and circuit training—hard periods of work combined with short rest intervals require ATP from anaerobic pathways, therefore leading to a significant EPOC effect. Doing a circuit involving both upper and lower body movements increases the demand for ATP from anaerobic pathways, which also places more stress on the aerobic system to replenish ATP during rest periods and post-exercise recovery period.
However, intensity is the biggest predictor of the level of EPOC—not duration. Higher intensities require ATP from anaerobic pathways to crank up your intensity and get going. Going hard for 3-4 minutes will be more effective for boosting the EPOC effect than going slower for longer.
Builds lean muscle mass
Exercises like burpees, squats, deadlifts, swings, and the like all get power from your trunk and legs, so building muscle in the lower body is easy, but a lot of HIIT exercises don’t incorporate the upper body, which means gaining upper body strength may be challenging. We’re about to change that game by throwing in a pair of dumbbells. You combine metabolic-based exercises with resistance training to maximize your ROI.
The one downfall of lifting for muscle growth is that if you’re lifting heavy, the lactic acid buildup can cut a workout short unless you have a buffering system that’s capable of ridding the lactic acid. While the body contains an inherent system to do that, it often can’t keep up, so fatigue sets it. When lactic acid accumulates, muscles become acidic, and muscle contractions stall.
However, metabolic resistance training can counteract these adverse effects by buffering lactic acid to prevent accumulation, allowing you to continue work. Plus, working at such high intensities boosts growth hormone releases, which can increase muscle protein synthesis for greater muscle growth.
Blasts fat (without compromising muscle)
When trying to lose fat, most people will hit the cardio machine. While there’s nothing wrong with working on endurance, losing fat with cardio is next to impossible, but it also jeopardizes your muscle mass—we want to avoid that. Good news: it doesn’t have to be that way. It is possible to lose fat without losing muscle. When you combine cardio and strength training, you’re getting the benefits of both—fat loss and muscle growth—without having to choose between the two. Studies prove it, too. They’ve found that weight loss with resistance training was more effective for fat loss than weight loss alone or weight loss with aerobic exercise.
Improves endurance
If you want to improve endurance, conventional advice will tell you to run—but I’m telling you, don’t. MRT is the way to go if you want a solid cardiorespiratory system. Oxygen consumption (VO2max) is one of the best measures of endurance that calculates the maximum volume of oxygen the body can use. Steady-state cardio has traditionally been viewed as the best way to improve endurance, but recent studies find that HIIT can produce the same benefits in significantly less time; it could enhance oxygen consumption by nearly 10% after just five weeks of performing HIIT four days per week for 20 minutes.
Remember that steady-state cardio is effective for enhancing endurance capabilities, but if you’re not keen on putting in hours on end to achieve an improvement, MRT will do it in less than half the time—you make the choice.
So, how can you shed fat and get shredded without spending hours in the gym? Here’s your 30-minute dumbbell shred metabolic workout that’ll light your entire body on fire and give you results you never thought possible.
30 Minute Total Body Dumbbell Shred Workout
Total Body Terminator Muscle Shred Workout
This is a total body workout focused on helping you build lean muscle while burning fat and get shredded. Perform each set one after the other with a 60 second break in between.
Set 1 – Body Part Exercises
Perform each exercise one after the other for 50 seconds of work followed by 10 second rest for 2 straight.
- Goblet Squat
- DB Chest Press
- Bent Over Rows
- Standing Cross Body Biceps Curls
- DB Lying Triceps Skull Crushers
- DB Forward Lunge
- DB Shoulder Press
Set 2 – Combo Exercises
Perform each exercise one after the other for 45 seconds of work followed by 15 second rest for 2 straight.
- DB Zercher Squat to Waiter Curls
- DB Plank Side Raises to T-Raise
- Bent Over Row to Alternating Reverse Curls
- Alt DB Chest Press to Alternating Skull Crushers
- DB Burpees
Set 3 – Single Limb - Unilateral Exercises
Perform each exercise one after the other for 30 seconds of work followed by 10 second rest for 2 straight rounds!
- Single Arm Squat and Press L
- Single Arm Squat and Press R
- Single Chest Press L
- Single Chest Press R
- Single Static Lunge to Hammer Curls L
- Single Static Lunge to Hammer Curls R