You can lift both heavy and light weights to lose weight as each offer unique benefits.
Below, I’ll explain those benefits and how to implement heavy and light training into your fat loss routine.
Lifting & Weight Loss Explained
Weight loss occurs when you are in a calorie deficit (taking in fewer calories than your body needs to maintain weight).
While lifting weights is one way to increase the calories you burn, your diet is the key factor for losing weight.
That said, lifting weights while actively eating less to lose weight is a great way (and then the best way) to ensure you are not losing muscle function, muscle tissue, or performance as you diet.
To do this, focus on eating fewer calories and training with weights 3-4 days a week while maintaining or adopting a physically active lifestyle.
As a general rule of thumb, aim to eat 10-15% below your maintenance calories, resistance training 3-4 days a week, and hit 10,000 steps daily.
If you can do this, you will be on the path towards losing weight without losing muscle (and potentially even building muscle).
Related Article: How To Plan Your Strength Training While Cutting
Lifting Heavy vs. Light For Weight Loss
Research has shown no difference between the weight or lean muscle changes depending on whether you lifted light or heavy loads during a dieting phase.
That said, training with heavy and light weights allows you to individualize your training based on your performance goals, either to maintain or improve your performance as you lose weight.
When you lift weights, you are setting out to increase your muscle’s capacity for strength (how much force they can exert), muscle hypertrophy (increases in muscle size), and muscle endurance (the ability of the muscle to resist fatigue with repeated use).
All three outcomes come from lifting weights in low, moderate, and high rep ranges.
Related Article: How Much Weight Can You Lose in 60 Days?
Lifting Heavy For Weight Loss
Lifting heavy consists of lifting loads above 80% of your one rep maximum or when doing hard, strenuous sets of 1-10 reps.
For most people, lifting heavy during a weight loss phase should be done in the 5-10 rep range. If you know your 1-rep max on a movement, this is done with 80-90% of your one-rep max.
Pros
Minimize Strength Loss When Dieting
Lifting heavy weights while dieting can help you preserve the strength you’ve built up to that point and potentially gain more strength.
Research shows that when lifting heavy weights, you do not need to train to failure (or as close to failure compared to training with lighter weights) to build strength.
If you decide to train heavy, you do not have to push to complete failure (unlike lifting light), as you can maintain your strength or even develop it further by including one main strength lift per session for 2-3 sets of 1-5 reps (between 80-95% max).
Cons
Difficult to Get Enough Training Volume In
Building lean muscle can be difficult if you cannot keep your volume high enough. Lifting only with heavy weights can make it challenging to get enough muscle stress and volume in to encourage muscle growth (as compared to training with lighter loads, in which you can easily get more volume).
If you do, however, have enough energy when losing weight to lift with heavier loads (and need to for your sport, for example, powerlifting), then make sure you perform many sets with heavier loads to get enough volume in to induce growth and maintain or gain strength.
Research shows that muscle growth was similar with light and heavy weights when volume was equated (3 sets of 10 with lighter weights vs. 7 sets of 3 with heavier weights), but they found that the 7 sets of 3 groups significantly increased their strength.
Could Increase The Risk Of Injury Risk
Overuse injuries can occur with both light and heavy lifting. However, heavier loads tend to stress the joints and connective tissues more than lighter loads.
When your calories are restricted, your ability to recover from challenging exercise is compromised. Training too often and with too heavy of weights can place excessive stress and strain on the connective tissues and joints, which may lead to injury.
This can be mitigated by following a program that allows your body to recover at an appropriate rate. However, your recovery rate will vary based on your abilities and nutrition.
Oftentimes, less is more when it comes to strength development and retention during a dieting phase, so ensure you are realistic with your strength goals when restricting your calories.
Lifting Light For Weight Loss
Lifting light weights means that you are lifting lighter loads but it does not mean that it involves less effort. When training with “light weights,” you typically perform 10-30 reps using 30-80% of your one rep max.
A wide range of reps and loads can be used for lightweight training; however, regardless of the load, you should still be training with hard intensity (training close to or to failure).
Too often, people will use weights that are too light when training in higher rep ranges simply because they mistake the term “lightweights” for “lower effort or intensity training.”
When training with lighter weights, you want to often perform as many reps as you can to failure (or within 1-2 reps shy of failure). Training with too little effort and intensity (not reaching failure) with too light of weights may be one big reason people don’t see results in the gym.
Pros
Increased Training Volume
When you train with lighter weights, you can perform more repetitions and deliver more volume to your muscles without compromising recovery.
Increasing training volume over time has been shown to have a dose-response relationship with muscle growth, meaning that as you do more work, you increasingly can develop more muscle tissue.
Yes, there is an upper limit; however, most people want to keep their training volumes high while dieting to minimize muscle loss. This involves training each muscle group twice weekly and delivering 12-16 total sets per muscle group.
Decreased Central Nervous System Fatigue
When training with light loads, you place less neurological stress on the body than you do with heavy loads. This is key during a weight loss phase because your body is already underfed and may not withstand high amounts of muscle stress with heavy loads in an underfed state. Prolonged exposure could lead to injury or overtraining.
Increased Caloric Expenditure (Burn More Calories)
Do more, burn more. When you are training with more volume, you demand more from your body and burn more calories. When losing weight, lifting with lighter weights can be a great way to build or preserve lean muscle mass while keeping your calorie output from exercise high.
Many lifters will do higher-rep workouts instead of cardio sessions to burn calories and encourage fat loss and muscle retention.
Can Build Muscle Without Heavy Weights
If you do not have access to heavy weights or you do not have the energy to lift heavy weights, you can train hard with light weights and still get enough training stimulus to build muscle or, at the very least, decrease muscle loss as you are losing weight.
This is especially helpful when combating low energy during a weight loss phase, as you can continue to train hard with weights (light weights) without the added neurological or joint/connective tissue stresses that sometimes come from training hard with heavy weights.
Cons
Will Not Help You Maintain Strength
If you want to improve your strength (or maintain it), you must train with loads heavier than 80% of your max. Lifting light weights will not produce the same neurological effect on the body as heavy loads, which is necessary if your focus is to build strength.
Can Be Very Tiring (Physically and Mentally)
You must train close to or to failure when using light weights in workouts. This often means you will be doing sets of 10-30 reps. Anyone training to failure for 20+ reps knows how stressful and tiring that can be.
A few lengthy sets can wipe out all your energy for the entire session, so only training with light weights can be very tiring during a weight loss phase.
This is why I tend to recommend most of your training should take place between the 10-15 rep range, as you can use lighter loads than if you trained in the 5-10 rep range but not have to do 20-30 reps every set (which ultimately will tire you out with less overall benefit).
Can You Lift Heavy & Light Weights To Lose Weight?
You can and should include a mixture and light and heavy weight training while dieting to reap the benefits of both. Training with heavy and light weights maximizes your performance potential (building strength, preserving lean muscle mass, and increasing energy expenditure).
I recommend that people training to lose weight train 25% of the time with heavy weights in the low rep ranges (5-10 reps) and the other 75% of the time with lighter weights in higher rep ranges (10-30 reps).
Generally speaking, you should include one compound movement (i.e. squat, bench press, deadlift, etc.) per session trained with heavy weights in the 5-10 rep range. This will help to preserve or build strength.
You can also add lighter-weight training in the 10-20 and 20-30 rep ranges. These movements can be both compound in nature or a single joint and should be trained closer to failure than your strength-building exercise.
By using both heavy and light weights in your training, you can deliver high amounts of work volume to the body to increase or retain muscle as well as increase your overall energy expenditure.
Sample Workout For Losing Weight
Related Article: Cutting Workout and Diet Plan
Below is a 4-day full body workout program to help you lose weight that integrates both heavy and light weight lifting.
Remember, the key to losing weight is to first be in a calorie deficit, which means you should eat 10-15% fewer calories than your body needs to maintain weight. You can determine how much you should be eating with the following resource.
For best results, you should also aim to perform 10,000 steps a day (outside of your workouts), complete all four workouts every week, and sleep at least 7 hours a night.
Note: The following workouts can be used as a template to help you design your workouts in the Fitbod app.
Day 1
- Barbell Bench Press: 4 sets of 6-8 reps, resting 2 minutes between sets
- Barbell Back Squat: 3 sets of 12-15 reps, resting 90 seconds between sets
- Perform 4 Rounds of:
- 15 Dumbbell Shoulder Presses
- 15 Dumbbell Lunges (per leg)
- 15 Barbell Rows
- Rest 30 seconds between exercises and 90 seconds between rounds
Day 2
- Trap Bar Deadlift: 4 sets of 6-8 reps, resting 2 minutes between sets
- Lat Pulldown: 3 sets of 10-15 reps, resting 90 seconds between sets
- Hack Squat / Leg Press: 3 sets of 10-15 reps, resting 90 seconds between sets
- Machine or Barbell Incline Bench Press: 3 sets of 10-15 reps, resting 90 seconds between sets
- Barbell Curl: 3 sets of 10-15 reps, resting 90 seconds between sets
- Triceps Pushdown: 3 sets of 10-15 reps, resting 90 seconds between sets
Day 3
- Barbell Squat: 4 sets of 6-8 reps, resting 2 minutes between sets
- Barbell Bench Press: 3 sets of 12-15 reps, resting 90 seconds between sets
- Perform 4 Round of:
- 15 Machine Assisted Pull Ups
- 15 Dips (Weighted or Machine Assist)
- 15 Dumbbell Split Squat (per let)
- Rest 30 seconds between exercises, 90 seconds between rounds
Day 4
- Romanian Deadlift: 4 sets of 6-8 reps, resting 2 minutes between sets
- Cable or Machine Row: 3 sets of 10-15 reps, resting 90 seconds between sets
- Barbell or Dumbbell Step Up: 3 sets of 10-15 reps, resting 90 seconds between sets
- Machine or Barbell Shoulder Press: 3 sets of 10-15 reps, resting 90 seconds between sets
- Cable or Machine Bicep Curl: 3 sets of 10-15 reps, resting 90 seconds between sets
- Skullcrusher: 3 sets of 10-15 reps, resting 90 seconds between sets
Looking for a workout program? Try using the Fitbod App, which will design your program based on your logged training data and goals. The workouts will adapt automatically to your levels of recovery and rate of progress. With over 600 movements and exercises videos, you can be sure to perform the movements correctly for optimal results. Take the guesswork out of your workouts. Try Fitbod for free.
About The Author
Mike holds a Master’s in Exercise Physiology and a Bachelor’s in Exercise Science. He’s a Certified Strength and Conditioning Specialist (CSCS), USA Weightlifting Advanced Coach, and has over 10+ years of experience working with collegiate athletes, national level lifters, and beginners alike. Mike is Founder of J2FIT Strength and Conditioning, a growing global training company with gyms in New York City, Cincinnati, and online offering personal training, online custom coaching programs.
