“My friend is a bodybuilder and told me not to lift heavy unless I’m trying to bulk up”
This sounds logical, so let me explain the issue with this statement.
The reason I think it’s important to address is because I believe many people avoid exercise altogether because of myths like this.
As a consequence, it is making them believe they’re doing the “wrong” thing- creating paralysis amongst people that need MORE strength training in their lives.
What we’re actually doing when we train
When you strength train, the goal is simple:
get stronger and build muscle.
Building muscle is called hypertrophy. There is no “bulking muscle” or “cutting muscle.” There’s just muscle that can:
- grow (hypertrophy)
- stay the same
- or shrink (atrophy)
Your body doesn’t look at your set and say, “Oh, this is a bulking workout,” or “This is a cutting workout.” The big difference between those phases is almost always nutrition (calories in vs. calories out), not the rep range.
How bulking and cutting got confusing
Bodybuilders popularized the terms:
- Bulking: eat more than you burn, gain muscle (and some fat)
- Cutting: eat less than you burn, lose fat and try to keep muscle
During bulks, they had more bodyweight and more fuel, so they felt stronger and often lifted heavier for lower reps.
During cuts, they were very lean and in a calorie deficit. Performance usually dropped, and trying to push max weights felt worse on the body and the ego. Many shifted to lighter weights and higher reps during that phase.
People connected the wrong dots:
- “I’m cutting and doing high reps → high reps must ‘cut’ the muscle.”
- “I’m bulking and lifting heavy → heavy weights must ‘bulk’ the muscle.”
In reality, it was the surplus or deficit driving the size changes, not the rep range itself.
What actually builds muscle?
We know now:
- Heavier weights / lower reps are best for building max strength.
- Lighter or moderate weights / higher reps can build just as much muscle as long as the sets are challenging and close to fatigue.
So:
- Heavy ≠ “bulking muscle”
- Light ≠ “cutting muscle”
Both can build muscle. The main difference is the feel and whether you’re training more for strength, endurance, or a mix.
What this means for you
For 99% of people training here:
You’re not doing extreme bulks and cuts like a bodybuilder prepping for a stage show. You’re trying to:
- Get stronger
- Build or keep muscle
- Change your body composition in a sustainable way
So the formula is:
- In the gym: We program a smart mix of rep ranges, keep you lifting challenging weights with good form, and progress you over time.
- Outside the gym:
- Eat in a slight deficit if your goal is fat loss
- Eat at maintenance or a small surplus if your goal is more muscle and strength
Same muscles. Same type of strength training.
The difference is what you’re doing with your nutrition, not whether you picked 6 reps or 15.
– James Pratt