Mike Mentzer “Heavy Duty” Workout Routine Explained

Mike Mentzer is a renowned bodybuilder and philosopher who is still remembered for being the creator of the “Heavy Duty” training regimen. Contrary to popular belief, Mike Mentzer followed his own methods that were based on a unique philosophy. Here, we’ll explore the Mike Mentzer “Heavy Duty” workout routine.

Mentzer was one of the very few men to win the Mr. Universe title with a perfect score. He was also one of the first bodybuilders to promote high-intensity training (HIT) as a method to build massive muscles. Mentzer left the world in 2001 at the age of just 49, unfortunately, but his training principles are still widely adopted.

What is the Mike Mentzer Workout Routine?

The “Heavy Duty” workout is one of the most intense training regimes for bodybuilding. Created by the legend Mike Mentzer, it was based on BowFlex Inc.’s founder Arthur Jones’ method but a lot more hardcore. It incorporates high-intensity training along with lower rep ranges and heavier weights.

Mentzer switched up 20-rep sets from Jones’ method to sets with 6 to 9 reps and made the plates much heavier. There were no limits to how heavy the weights could be. The sole purpose was to reach absolute failure in the given number of reps. He aimed at destroying a muscle group entirely before letting it recover for a few days. His key principle was that intensity was more important than frequency for muscle growth.

There were many elements in the Mike Mentzer Heavy Duty workout such as rest pauses, forced reps, negative reps, and more. We have explained the terminology below:

• Rest Pause: After reaching failure, rest for around 15 seconds and then perform another rep. Next, repeat for 2-3 reps. Mentzer had one more way of doing a rest-pause set: 4-6 max single reps with a rest of 10-15 seconds between each rep and a 20% reduction of weight near the end to get that last rep or two.
• Forced Reps: A spotter helps just enough to keep the weight moving for additional repetitions.
• Negative Reps: A spotter helps a lot on the positive halves of reps, and you then slowly lower the weight over approximately six seconds.
• Pre-Exhaust Supersets: Do a set of an isolation exercise before a set of a compound exercise for that same body part without resting. The muscles targeted with the isolation exercise work to their maximum and give out first during the compound exercise.

How to Follow the “Heavy Duty” Training Regimen?

The Mike Mentzer “Heavy Duty” workout routine is usually split into two days of working out and then five days of rest. On the two days, all major muscles including the chest, shoulder, biceps, back, triceps, and legs are targeted with heavy intensity, heavy weights, and low reps to completely exhaust them.

All the reps are to be taken to failure, even if you need to do forced reps, negative reps, and rest pauses. However, remember to stretch yourself and get warmed up properly for the big lifts. But, don’t go more than 75% of your working weight during the warm-up sets to not leave yourself exhausted entirely.

Make sure that you’re training with at least one partner as you’ll need them for the exercises. Mike Mentzer himself trainer with his younger brother Ray, whom you might know as the 1979 Mr. America winner. Another important aspect you need to focus on is maintaining proper form even if it means moving slower.

What is the Story Behind Mentzer’s Heavy Duty Workout?

The story begins with a young boy, 12 years old, named Mike Mentzer who started lifting at this age. The same guy could bench more than 350 pounds at the age of 15. He competed in the 1971 Mr. America contest but placed tenth. The winner of the competition, 19-year-old Casey Viator, then introduced him to his trainer Arthur Jones. This was the beginning of the formation of the Heavy Duty training regimen.

Mike Mentzer then started training under Jones and went on to win the 1976 Mr. America. He was widely celebrated both for his victorious physique and his unique training regimen. He also wrote articles for the top bodybuilding magazine of the era, Muscle Builder/Power, and focused on intensifying workouts.

After finishing fifth in 1980 Mr. Olympia Arnold Schwarzenegger won, and Mentzer left training, possibly due to the controversial decision. However, his training techniques were getting adopted and they were revolutionizing bodybuilding. Dorian Yates became one of the followers and went on to win six consecutive Olympia titles with the HIT method. Almost 50 years later, we’re still discussing the unique regimen.

Mike Mentzer Workout Routine: 2-Day Split:

There are two different ways to use the Mike Mentzer workout routine. The first one is split into a two-day routine where you target all the muscles in two days followed by a sufficient period of rest. The next one is split into different muscle groups and spanned across five days of training and then two days of rest.

First, let’s take a look at the OG Heavy Duty workout routine recommended by Mike Mentzer:

Day One:

Legs:

• Leg Extension Superset W/ Leg Press: 1 set of 6 – 8 reps
• Squats: 1 set of 6 – 8
• Leg Curls: 2 sets of 6 – 8
• Calf Raises: 2 sets of 6 – 8
• Toe Presses: 1 set of 6 – 8
• Incline barbell bench press: 3 sets of 6 to 10 reps

Chest:

• DB Flys or Pec Deck Superset W/ Incline Bench Press: 1 – 2 sets of 6 – 8
• Dips: 2 6 – 8

Triceps:

• Pushdowns Superset W/ Dips: 1 set of 6 – 8
• Lying Triceps Extensions: 2 sets of 6 – 8

Day Two:

Back:

• Nautilus pullovers Superset W/ Close-Grip Underhand Pulldowns: 2 sets of 6 – 8 reps
• Bent-Over Barbell Rowing: 2 sets of 6 – 8 reps

Traps:

• Universal Machine Shrugs Superset W/ Upright Rowing: 2 sets of 6 – 8 reps

Shoulders:

• Nautilus Side Laterals Superset W/ Nautilus Presses: 2 sets of 6 – 8 reps
• DB or Machine (Reverse Pec Deck) Rear Delt Rowing: 2 sets of 6 – 8 reps

Biceps:

• Standing Barbell Curls: 1 set of 6 – 8 reps
• Concentration Curls: 2 sets of 6 – 8 reps

Mike Mentzer Heavy Duty Workout 5-Day Split:

After evolving throughout the years, the Mike Mentzer “Heavy Duty” workout routine can also be spanned across five days. However, you may have to turn down the intensity and follow a moderate route for that. Here’s how you can follow the training regimen in a five-day workout split:

Monday: Chest

• Incline Dumbbell Flyes: 5 sets of 8 reps
• Bodyweight Dips: 5 sets x 6 reps (60 seconds rest)
• Incline Bench Press: 5 sets at 6-8 reps
• Flat barbell bench press: 5 sets at 6-8 reps
• Flat dumbbell fly: 5 sets at 6-8 reps

Tuesday: Back

• Straight Arm Lat Pulldown: 5 sets of 5-8 reps
• Reverse Close Grip Cable Pulldown: 5 sets of 8-10 reps
• Barbell Bent-Over Row: 5 sets of 5 reps
• Standing Barbell/DB Shrugs: 5 sets of 8-10 reps
• Barbell Upright row: 5 sets of 6-8 reps

Wednesday: Shoulders

• Bent Over Dumbbell Raise: 5 sets of 8-10 reps
• Seated Machine Press: 5 sets of 6-8 reps
• Dumbbell Side Lateral Raise: 5 sets of 8-10 reps
• Behind The Neck Overhead Press: 5 sets of 6-8 reps*
• Front Barbell Raise: 5 sets of 8-10 reps

Thursday: Legs

• Single Leg Extensions: 5 sets of 8-10 reps
• Single Leg Hamstring Curl: 5 sets of 8-10 reps
• Barbell Squats: 5 sets of 6-8 reps
• Leg Press: 5 sets of 6-8 reps
• Standing Calf Raise: 5 sets of 10-15 reps
• Walking Dumbbell Lunges: 5 sets of 8-10 reps

Friday: Arms

• Reverse Grip Chin-Up: 5 sets of 6-8 reps
• Bodyweight Dips: 5 sets of 10 reps
• Barbell Preacher Curl: 5 sets of 8-10 reps
• Triceps Cable Pushdowns: 5 sets of 8-10 reps
• Standing Dumbbell Curl: 5 sets of 8-10 reps
• Overhead Triceps Cable Extension: 5 sets of 8-10 reps
• Barbell Reverse Grip Forearm Curls: 5 sets of 8-10 reps

How was Mike Mentzer’s Diet?

Mike Mentzer had a very different approach to diet as well. Despite having a very strict training regimen, his diet and eating habits were pretty lenient. He didn’t pay much attention to what he was eating but always made sure that he was consuming enough calories while bulking and restricted them for cutting.

Mentzer stated that lifters should eat 4 servings each of fruit and high-quality grains along with 2 servings each of protein and dairy in a day. He wasn’t a big supporter of high protein diets and believed that 1.2 grams per pound of body weight wasn’t necessary to build strong muscles.

He followed a mostly balanced diet focused on completing his calorie goals instead of tracking macros. Mentzer suggested keeping a food diary to help with perfecting your diet plan and recommended the high-carb diet to beginners. He believed some fat gain was necessary to build muscles quickly and efficiently.

What did Mike Mentzer eat?

Mike Mentzer didn’t follow a restrictive diet but he still refrained from eating sugary, processed, and fried foods. However, he was often seen eating ice cream without any guilt in an era when other bodybuilders saw it as taboo. He would eat anything he liked as long as it helped him reach his caloric intake.

When Mentzer was trying to stay lean, he restricted himself to eating less than 2,000 calories a day. He ate the following food items regularly to do that:

• Red meat
• Fish
• Eggs
• Poultry
• Peanut butter
• Milk
• Yogurt
• Fruits, berries
• Vegetables
• Bread
• Pasta
• Butter
• Whole Grains
• Lentils
• Juices

It’s worth noting that Mentzer burnt a lot of calories in the gym. If he was consuming more than 4,000-5,000 calories a day, he was also utilizing them through his heavy-duty, high-intensity training routine.

Which Supplements did Mike Mentzer take?

Mike Mentzer belonged to an era when steroids were a norm in bodybuilding. He openly admitted taking them but also consumed some other supplements for his monstrous yet aesthetic physique:

• Whey Protein: It’s a great source of protein to build muscles and one can easily sip it as a shake.
• Creatine: It’s one of the most popular and safe supplements to boost energy during intense workouts. It also improves muscle strength, size, and performance.
• Beta-alanine: It improves exercise performance and bodybuilders often take it as a pre-workout. It also helps in building muscle mass and aids recovery.
• Branched-chain amino acids: BCAA stimulates the building of protein in muscle and reduces muscle fiber breakdown.

Mentzer always backed his philosophy with modern science and research. He was always updated with the latest findings and it helped the legendary bodybuilder revolutionize the world of bodybuilding.

Final Thoughts:

This was the “Heavy Duty” workout created by Mike Mentzer. There may be many scientific arguments against the training regimen and it may not be viable for everyone, especially for beginners and intermediate bodybuilders. However, it worked for many professionals including Mentzer himself.

Dorian Yates is another legend who helped popularize this training regimen. You can also give it a shot if you’re a seasoned lifter who’s trying to build massive muscles with a vigorous workout routine. One advantage of this regimen is that you don’t have to hit the gym the whole week. However, we would still not recommend this approach to working out as it comes with several big risks.

That’s all for this guide. If you have any doubts regarding the Mike Mentzer training regimen, feel free to use the comment box. We’ll be glad to assist you more.

Disclaimer: Do not follow the Mike Mentzer “Heavy Duty” workout routine, his diet, or his training philosophy blindly as it’s not meant for everyone. If you’re planning to try it, make sure you consult with your personal trainer about and educate yourself thoroughly about the risks involved.

Frequently Answered Questions:

Here are the most frequently asked questions about the Mike Menzter workout and diet:

What was Mike Mentzer’s height and weight?:

Mike Mentzer stood at 5 feet 6 (1.73 meters) and weighed around 224 lbs (102 kg). He had a monstrous physique for his stature which was a result of his strict heavy-duty, high-intensity workout, and an unconventional dietary approach.

How many hours a day did Mike Mentzer train?:

Mike Mentzer followed an unconventional approach to working out and trained for only 30 minutes a day and four times a week. Sometimes he only went to the gym once or twice a week. He didn’t work out for 2 to 4 hours a day and for 5-7 days a week like other bodybuilders.

What is Mike Mentzer’s pre-exhaustion training?:

Mike Mentzer followed an innovative approach called pre-exhaustion training. It was based on isolating and fatiguing the target muscle group with an isolation exercise, followed by a compound movement that recruits multiple muscle groups. This helped in the overall growth of the region.

Why did Mike Mentzer quit bodybuilding?:

Mike Mentzer quit the world of bodybuilding after the controversial decision at the 1980 Mr. Olympia where he placed fifth overall. He left training due to the backroom deals and underhanded tactics used by influential individuals in the sport. He believed that the contest was not only based on the athlete’s hard work and talent but on favoritism, bribes, and personal connections.