I Tried Chris Bumstead’s Modern Classic Physique Split for 21 Days — Here’s What Happened

The six-time Classic Physique Olympia champion Chris Bumstead is arguably the most popular bodybuilder of this era. “CBum” dominant reign in the Classic Physique division solidifies his status as a master of aesthetics.

I have long admired Bumstead’s training philosophy which underscores the importance of balanced muscle development — carving broad shoulders, a tiny waist, and sprawling legs.

A physique like Bumstead’s is hard to achieve. Nonetheless, I embarked on a 21-day challenge to train like Bumstead and strive toward his physique ideals. In this article, I share my experience with this modern classic physique split and the results I achieved. I’ll also share tips on how you can adopt this challenge in your own routine.

The Modern Classic Physique Split: Breaking Down the Arnold Split

The Classic Physique division was introduced after the Men’s Open division athletes started receiving a lot of backlash in 2015 and 2016 for pushing the human body too far and having aesthetically unappealing characteristics like an extended gut.

Arnold Schwarzenegger is considered one of the driving forces behind the CP division as he criticized the shape and balance of the Men’s Open bodybuilders on several forums and called for the introduction of a new division.

Athletes in the Class Physique (CP) division follow the same aesthetic principles as the bodybuilders of the golden era (1960-1980s).

The IFBB Pro League, the biggest bodybuilding federation in the world and the organizer of the Mr. Olympia contest officially introduced the CP division in 2016.

Bumstead dominated the CP division for six straight years, winning the prestigious Olympia trophy from 2019 to 2024 before hanging his posing trunks.

Besides his achievements on stage, Bumstead has built a thriving career as an entrepreneur. He owns multiple successful fitness-related companies and recently launched a new training app called STNDRD.

I signed up for the STNDRD app and was excited to see that Bumstead had a 21-day Arnold split. It’s a fitting tribute to the guy who brought bodybuilding into the mainstream and then played a huge role in reshaping the sport.

As soon I started the program, I realized it was not a typical Arnold routine, as I had done several of his programs. Bumstead put his own spin on the Arnold split, making it suitable for the modern era.

Since I was looking for a short and effective workout program, I signed up instantly.

Weekly Structure

This 21-day split involves training six days a week. The breakdown is as follows:

• Day 1: Chest & Back
• Day 2: Shoulders & Arms
• Day 3: Legs
• Day 4: Rest
• Day 5: Chest & Back
• Day 6: Shoulders & Arms
• Day 7: Legs

This routine involves training each muscle group twice weekly and the structure allows for focused attention on specific muscle groups, ensuring maximum target muscle fiber stimulation and subsequent adaptations.

Research suggests that increasing your training frequency can result in higher muscle and strength gains. (1)

Workout Breakdown: A Detailed Look

Make no mistake, Bumstead’s workouts aren’t the typical gym bro sessions you see on Instagram. He uses several advanced training principles in his workouts, like dropsets and supersets to push his muscles to the limit and ignite new muscle tissue growth.

Here’s a look at his actual training sessions:

Day 1: Chest and Back

Training in the 8-15 range is the most optimal for promoting hypertrophy and building a balanced, classic physique (2). Plus, in line with CBum’s training principles, I kept my rest duration short to maintain a high training intensity and boost muscle fiber recruitment.

In the workouts below, I incorporated drop sets by performing the last set of an exercise with the heaviest weight possible which allowed me to complete the recommended reps. Then, I lowered the weights and performed another set of the same number of reps without any rest in between.

Technique	Exercise	Sets	Reps	Rest (Seconds)
Drop Set	Seated Close-Grip Cable Row	3	15, 15, 12 (12)	60
	Incline Pronated DB Bench Press	4	12, 12, 10, 8	60
Drop Set	Hammer Strength Flat Chest Press (Drop set)	2	10, 10 (10)	60
Superset	a. Cable Chest Fly – High to Low	3	15, 12, 10	60
	b. Push Ups	3	AMRAP	60
Superset	a. Cable Rope Pullover	3	12, 12, 10	60
	b. Underhand Lat Pulldown	3	10, 10, 8	60
	Barbell Deadlift – Clean Grip	4	12, 12, 8, 6	60
	Lying Leg Press	3	15, 15, 15	60

Day 2: Shoulders and Arms

Bumstead’s workouts involve a balance of compound and isolation movements to build a solid foundation and improve muscle balance and definition.

Technique	Exercise	Sets	Reps	Rest (Seconds)
	Standing Chest Supported DB Side Lateral Raise	3	12, 12, 10	60
	Seated DB Shoulder Press	4	12, 12, 10, 8	60
Superset	a. Cable Rope Upright Row	3	12, 12, 10	60
	b. Cable Rope Front Raise	3	10, 10, 8	60
Superset	a. Seated Rear Delt Flyes	4	15, 15, 12, 12	60
	b. Band Pull Aparts	4	12, 12, 12, 12	60
Superset	a. Cable Rope Tricep Pushdowns	3	12, 12, 10	60
	b. Cable Rope Overhead Tricep Extensions	3	12, 12, 10	60
Superset	a. Straight Bar Underhand Cable Tricep Pushdown	3	10, 10, 8	60
	b. Straight Bar Cable Pushdown	3	12, 12, 10	60
Superset	a. Barbell Concentration Curl	3	12, 12, 10	60
	b. Seated DB Curls	3	10, 10, 8	60

Day 3: Legs

Progressive overload is the name of the game when it comes to building the physique of your dreams. This involves gradually increasing the load on your muscles by increasing the training volume and intensity.

Since I performed these same workouts over the three-week period, I aimed to increase the weight in each exercise by at least 2.5 pounds each week while ensuring I did not compromise my training technique.

Technique	Exercise	Sets	Reps	Rest (Seconds)
Superset	a. Leg Extensions	3	12, 12, 10	60
	b. Lying Leg Curl – Neutral (Plantarflexed)	3	10, 10, 8	60
	Barbell Back Squat	4	8, 8, 5, 3	60
Drop Set	Leg Press Wide Stance	4	15, 12, 10, 6 (6)	60
	DB Bulgarian Split Squat	4	12, 12, 10, AMRAP	60
	Hyperextensions	3	15, 15, 12	60
	Barbell Walking Lunges	3	10, 10, 8	60

Remember, you must learn to listen to your body and adjust your training routine based on how your muscles are responding. Feel free to take an additional day off from training if you’re feeling fatigued. This is your body telling you that it needs more time to recover.

Week 1: Diving into the Split

Even though I have been in the bodybuilding game for a very long time, I still get a little nervous starting a new program, especially when it is something like this 21-day split.

I won’t lie, the overall training volume hit hard during the very first workout. Multiple sets of incline dumbbell presses and barbell deadlifts tested my strength and endurance. The pump in my chest was imitated, but so was the fatigue. I definitely experienced a decline in performance as the workout progressed.

As I had expected, I woke up with significant delayed onset muscle soreness (DOMS) the next day. Even though the shoulders and arms are relatively smaller muscle groups, the intensity of the workout took me by shock. I don’t remember the last time I felt such an incredible pump in my shoulders. And when it comes to the biceps, I felt that they could burst at any moment.

Turns out that I was not as strong as I had thought. This routine revealed the gaps in my physique.

I was already bracing for the leg day after what had happened in the first two sessions. The soreness was profound and walking down the stairs after the workout was a battle in itself.

Instead of turning into a couch potato on the guest day, I went outdoors for a 20-minute walk to promote blood flow throughout the body and boost recovery.

Although round two was just as challenging, I was now better prepared, which helped me navigate through the workouts.

Weeks 2 and 3: Hitting My Stride

While the first week was all about letting my body adapt to this high-volume workout routine, I prioritized developing a deep mind-muscle connection and contracting my muscles throughout the range of motion in the final two weeks. This resulted in much better muscle pumps and results.

The consistent chest work yielded noticeable results as my pecks appeared fuller, creating a more defined upper body. I also gained significant size and definition in my triceps, which have been a lagging muscle group for me.

As my strength increased, I adjusted the weights to maintain the 8 to 12 range in the second and third weeks. At the same time, I performed each repetition with a picture-perfect form to maximize muscle engagement and limit the risk of injury.

That said, while the rep ranges were pretty standard throughout the 21 days, I had to constantly tweak the rest durations to ensure I was properly rested and could give my best in each set. This meant that I rested up to 120 seconds after some exercises.

I also used active recovery techniques like sports massages, cold plunges, and foam rolling on my days off to recuperate faster.

By the end of the second week, I noticed an improvement in my overall physique symmetry as my back started to match my chest. It did not end there, I hit a squat PR in the second week, reinforcing this program’s ability to build strength and power as well.

My muscle separation and definition were my main focus going into the final week and this Arnold-inspired split didn’t disappoint.

This 21-day training split is as mentally demanding as it is physically challenging. The 3-on-1-off schedule demands consistency and commitment. I started feeling fatigued by Day Four itself and had to mentally psyche myself up to push through the remainder of this challenge.

The Results: What Changed After 21 Days

Let’s now dig into the results, because this is why we put ourselves through so much pain. Here are my numbers:

Measurement	Before (Units)	After (Units)	Change (Units)
Weight	185 pounds	188 pounds	+3 pounds
Chest Circumference	44 inches	45 inches	+1 inch
Shoulder Width	50 inches	51 inches	+1 inch
Waist Circumference	32 inches	31.5 inches	-0.5 inches

Bumstead’s 21-day modern classic physic split highlights the importance of balance in physique development and how each muscle group contributes to overall symmetry.

I noticed an improvement in my overall physique as I got stronger and gained muscle mass. Training every muscle group twice weekly improved my V-taper and symmetry, creating a classic physique silhouette.

I added 20 pounds to my bench press, reflecting significant upper-body strength gains. More importantly, this high-volume program also improved my form and I now feel more comfortable and confident while lifting heavier.

The 21-day duration of this high-volume, high-intensity program makes it ideal for a trial period. Since I got satisfactory results from this routine, I decided to continue with it for an additional nine weeks.

I must add that this training routine is ideal for intermediate and advanced athletes with decent lifting experience.

Conclusion

Bumstead’s 21-day modern classic physique split helped me achieve a level of muscle balance that I never had before. I gained an inch in my chest and shoulders, which is a big achievement in just three weeks.

Like any other training program, consistency and discipline are key to achieving your training goals in these three weeks. Beginners should start small by training each muscle group once a week and increase the training volume and frequency as they gain more experience.

If you have any questions about Chris Bumstead’s 21-day modern Classic Physique split or need help implementing it into your own routine, post them in the comments below, and I’ll be happy to help!

References:

1. Schoenfeld BJ, Ogborn D, Krieger JW. Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis. Sports Med. 2016 Nov;46(11):1689-1697. doi: 10.1007/s40279-016-0543-8. PMID: 27102172.
2. Schoenfeld BJ, Grgic J, Van Every DW, Plotkin DL. Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum. Sports (Basel). 2021 Feb 22;9(2):32. doi: 10.3390/sports9020032. PMID: 33671664; PMCID: PMC7927075.

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