What Actually Drives Hypertrophy? (And Why There’s No Magic Lift)

Kyle Zulon
Jun 29
3 min read

Cut Through the Noise

Everyone wants to know the best lift for muscle growth. Incline Smith press? Seated cable fly? Dips? But here’s the truth: Hypertrophy has less to do with which exercise you pick… and more to do with how you train it. If you’ve ever found yourself frozen by conflicting advice online - ranking top lifts, comparing angles, or obsessing over machines vs. free weights, you’re not alone. But let’s simplify the process. Hypertrophy training comes down to principles, not just movements. In this post, I’ll break down the three core drivers of muscle growth, why no single lift is “optimal” for everyone, and how I apply this intelligently inside GritLab.

The 3 Evidence-Based Drivers of Hypertrophy

Mechanical Tension

Mechanical tension is the most critical driver of hypertrophy. It refers to the force placed on a muscle as it contracts against resistance, particularly when lengthened under load.

Studies have shown that high mechanical tension activates mechanosensors within muscle fibers, triggering molecular pathways (like mTOR) that initiate muscle protein synthesis (Schoenfeld, 2010).

TL;DR: If the muscle isn't under enough tension, growth won't happen.

This doesn’t require a barbell. You can create tension with machines, dumbbells, cables, bands, and even your own body weight. The key is as long as the load challenges the target muscle through a meaningful range of motion and close to muscular failure. There will be sufficient stimulus to promote hypertrophy.

Muscle Damage

Muscle damage results from high-force eccentric contractions and novel movement patterns that disrupt muscle fibers and connective tissues. While not essential for hypertrophy, moderate muscle damage may stimulate growth by initiating an inflammatory and repair response that leads to stronger, thicker fibers over time (Schoenfeld 2010). That said, too much damage can hinder recovery. At GritLab, we chase productive damage, not soreness for the sake of soreness.

Metabolic Stress

The “pump” isn’t just a gym bro myth. Metabolic stress results from the accumulation of lactate, hydrogen ions, and cellular swelling during higher-rep, lower-rest training. This environment causes hormonal changes, cell signaling, and fiber recruitment that all promote hypertrophy (Schoenfeld, 2010).

Ever finish a hard set and feel your muscles about to explode? That’s metabolic stress driving growth.

Volume work, drop sets, rest-pause, and short rest intervals are all effective ways to trigger this pathway.

It’s Not the Lift - It’s the Execution

When it comes to hypertrophy, execution > exercise selection. That means:

Lifting with intent and control
Applying progressive overload
Choosing movements you can recover from
Feeling the target muscle work (not just moving weight)

The best lifters don’t chase lifts. They build them to match their body and goal.

The Role of Variation

Too much novelty is noise. But strategic variation? That’s a powerful tool.

At GritLab, we use the Conjugate Method to rotate exercises weekly or biweekly. This prevents the law of accommodation (when gains stall due to overused patterns) and helps:

Distribute joint stress
Stimulate new fibers
Challenge new angles and ranges

We pick variations that allow each trainee to apply tension effectively and adhere to one of the three mechanisms of hypertrophy at all times. If it fits your structure, the part of your training program you're in, and you can progressively overload over time, it’s optimal for you.

The Repetition Method in GritLab

The Repetition Method is our primary hypertrophy tool at GritLab.

These are high-effort sets, close to muscular failure with submaximal loads focused on building up weak points and growing muscle through all three hypertrophy drivers:

Mechanical Tension through full ROM and controlled eccentrics
Muscular Damage from novel angles and long muscle lengths
Metabolic Stress via high volume, short rest, and effort-based training

This isn’t random bodybuilding fluff. It’s science-based, results-driven, and scalable for every level.

This is how we train hypertrophy at GritLab. Not by guessing. Not by chasing the trends. But by understanding what grows muscle and applying it week after week.

🔗 Already wrote an article breaking this down, learn more here!

📌 Final Word: Train With Principles, Not Trends

Your best hypertrophy tool isn’t a trending lift. It’s a system built on progression, quality execution, principles, and smart variation. That’s how we train at GritLab and it’s how you build body armor.