Learning from Francis Holway
The scientist who proved there's a limit to how much muscle you can build—and it's written in your bones
The Story
Francis Holway has spent 25+ years measuring elite athletes—from River Plate footballers to Olympic judokas to NHL hockey players.
He discovered something that contradicts most fitness marketing: Your skeleton determines how muscular you can become.
No matter how much you train, no matter how much protein you eat, there's a biological ceiling for muscle mass based on your bone structure. Holway calls this the "Muscle-to-Bone Ratio" (MBR), and his research shows the natural limit is approximately 5:1.
This isn't depressing news—it's liberating. It means:
- You can stop chasing impossible goals
- You can optimize for YOUR frame
- You can know when to shift focus from size to power/speed
Who is Francis Holway?
| Credential | Detail |
|---|---|
| Education | Master of Science in Nutritional Science, San Jose State University |
| Certifications | ISAK Level 4 Criterion Anthropometrist (fewer than 20 worldwide) |
| Experience | River Plate, Boca Juniors, Argentine Rugby Union, NHL, NFL, NBA consulting |
| Known For | Muscle-to-Bone Ratio theory; massive athlete datasets; "structure-first" approach |
Holway combines North American academic rigor with South American practical application—measuring real athletes in real locker rooms.
What ISP Students Learn
Lesson 1: You Can't Flex Bone
Holway's central insight: the skeleton isn't just a coat hanger for muscle—it's a structural determinant of how much muscle can be supported.
The mechanism: Robust bones (high density, large widths) provide:
- Greater surface area for muscle attachment
- Higher tolerance for contractile forces
- Better leverage for power production
A gracile (thin-boned) skeleton has a lower ceiling, regardless of training or nutrition.
The natural limit:
- Men: MBR of ~5.2 to 5.5 kg muscle per kg bone (natural ceiling)
- Women: MBR of ~4.5 kg muscle per kg bone
"You cannot flex bone."
What this means for young athletes: Your frame determines your potential. A light-boned athlete trying to become a heavyweight is fighting biology.
Lesson 2: Structure Is Destiny (And That's OK)
This sounds like bad news. It's actually freedom.
For talent identification: Young athletes with smaller frames shouldn't pursue positions requiring massive absolute size (rugby prop, heavyweight rower). They should leverage their advantages—speed, agility, power-to-weight ratio.
For training focus: An athlete at MBR 5.0 who keeps trying to "bulk" will:
- Hit diminishing returns
- Likely gain fat instead of muscle
- Risk overuse injuries from overloading the frame
Better to shift focus from hypertrophy (building the engine) to neural adaptation (tuning the engine).
What this means for young athletes: Know your frame. Optimize for what's realistic, then shift to other performance variables.
Lesson 3: The Five-Way Body Breakdown
Holway doesn't just measure "body fat percentage." He uses a five-way fractionation that provides much higher resolution:
| Component | What It Is | Why It Matters |
|---|---|---|
| Skin | Surface covering | Minor contribution |
| Adipose | Fat tissue (including supporting structures) | "Parasitic" weight in locomotive sports |
| Muscle | Contractile tissue | Power production |
| Bone | Skeletal framework | Structural limit for muscle |
| Residual | Organs, viscera, blood | Metabolic overhead |
This prevents the common error of calling a heavy, large-boned athlete "overweight" or a light-boned, under-muscled athlete "lean."
What this means for young athletes: "Body fat percentage" alone is misleading. Two athletes with the same body fat can have completely different body compositions.
Lesson 4: The Damage Control Protocol
Holway has studied weight-class sports (MMA, wrestling, judo) extensively. His research shows that extreme weight cutting causes:
- Cognitive impairment (slower reactions, poor decisions)
- Power loss (strength preserved, but explosiveness drops)
- Hormonal chaos (cortisol spikes, catabolic state)
His solution: The gradual descent
| Phase | What to Do | Timing |
|---|---|---|
| 1. Body composition | Lose adipose mass through caloric deficit | Weeks in advance |
| 2. Gut content | Low-fiber diet to reduce fecal bulk | 3-4 days before |
| 3. Water/sodium | Water loading then restriction | 24-48 hours before |
| 4. Rehydration | 150% of lost fluid with electrolytes | Post weigh-in |
The goal: arrive at weight having lost minimal functional tissue.
What this means for young athletes: If you're in a weight-class sport, make weight smart. The science exists—use it.
Key Takeaways
| Lesson | One-Liner |
|---|---|
| Bones set limits | Your skeleton determines your muscle ceiling |
| Structure is destiny | Optimize for your frame, don't fight it |
| Measure properly | Five-way fractionation beats body fat percentage |
| Cut smart | Extreme weight cutting destroys performance |
How This Shows Up at ISP
Francis Holway's structural approach shapes how ISP thinks about body composition:
- We teach realistic goal-setting based on frame
- Body composition education goes beyond simple "fat percentage"
- Weight-class sport guidance is science-based
- "Bulking" programs are evaluated against structural limits
When ISP students think about their bodies, they think about optimizing their unique structure—not chasing someone else's physique.
The Soccer Insight
Holway's FUTREF project studied 750+ Argentine soccer players. Key findings:
Center backs: Tall, heavy skeleton, high absolute muscle mass (for aerial duels, physical blocking)
Offensive midfielders: Shorter, lighter skeleton—but often higher relative muscularity. Their "engine" is massive relative to their "chassis," enabling extreme acceleration in tight spaces.
The warning: Trying to "bulk up" smaller midfielders to match defender weight would ruin their specific performance advantage.
What this means for young athletes: Position matters. Different roles require different body compositions. Don't try to be something your frame wasn't built for.
On Nutritional Tribes
Holway warns against "Nutritional Jails"—rigid adherence to dietary ideologies (Paleo, Keto, Vegan, Carnivore) that ignore individual physiology.
His approach:
- Guide athletes back to physiological principles (energy balance, glycogen, protein synthesis)
- Accommodate beliefs where possible
- Gently steer away from dogma when performance suffers
"The best diet is the one that works for YOUR body and YOUR sport."
Learn More
"The most sophisticated technology in sports science is often the ability to measure, interpret, and apply the fundamental laws of human structure."