PHUL & PHAT: Daily Undulating Periodization — Evidence Check
You’re past the beginner phase. StrongLifts has stalled, GZCLP has run its course, and you want to get both stronger and better looking. Welcome to PHUL and PHAT — two programs that combine strength and hypertrophy in the same week.
This article explains both programs, the DUP principle behind them, and how research evaluates the combination of power and hypertrophy training.
The Principle: Daily Undulating Periodization (DUP)
Traditional periodization switches the training goal across weeks or months: first hypertrophy phase (4 weeks), then strength phase (4 weeks), then peaking.
DUP switches within the same week: Monday strength, Thursday hypertrophy. Or even within the same session (PHAT with speed work).
Why DUP Works
The results are clear: at equal total volume and intensity, DUP produces substantially more strength gains than linear periodization. The difference: stimulus variance. DUP challenges the body with changing rep ranges instead of providing the same stimulus for weeks.
PHUL: Power Hypertrophy Upper Lower
Structure: 4 Days/Week
| Day | Focus | Rep Range |
|---|---|---|
| Monday | Upper Power | 3-5 reps (heavy) |
| Tuesday | Lower Power | 3-5 reps (heavy) |
| Wednesday | Rest | — |
| Thursday | Upper Hypertrophy | 8-12 reps (moderate) |
| Friday | Lower Hypertrophy | 8-12 reps (moderate) |
Upper Power (Monday)
| Exercise | Sets × Reps | Type |
|---|---|---|
| Barbell Bench Press | 3-4 × 3-5 | Compound, heavy |
| Incline Dumbbell Bench Press | 3-4 × 6-10 | Compound |
| Bent Over Row | 3-4 × 3-5 | Compound, heavy |
| Lat Pulldown | 3-4 × 6-10 | Compound |
| Overhead Press | 2-3 × 5-8 | Compound |
| Barbell Curl | 2-3 × 6-10 | Isolation |
| Skull Crusher | 2-3 × 6-10 | Isolation |
Upper Hypertrophy (Thursday)
| Exercise | Sets × Reps | Type |
|---|---|---|
| Incline Barbell Bench Press | 3-4 × 8-12 | Compound |
| Dumbbell Fly | 3-4 × 8-12 | Isolation |
| Seated Cable Row | 3-4 × 8-12 | Compound |
| One Arm Dumbbell Row | 3-4 × 8-12 | Compound |
| Lateral Raise | 3-4 × 8-12 | Isolation |
| Incline Dumbbell Curl | 3-4 × 8-12 | Isolation |
| Cable Tricep Extension | 3-4 × 8-12 | Isolation |
PHUL Advantages
- 2×/week each muscle group — optimal for hypertrophy (Schoenfeld 2016)
- Only 4 days/week — time-efficient compared to PPL (6 days)
- Strength AND hypertrophy — not either/or
- Flexible — exercise selection customizable
PHAT: Power Hypertrophy Adaptive Training
Created by Layne Norton
PHAT was developed by Dr. Layne Norton — a bodybuilder and scientist with a PhD in Nutritional Sciences. The program adds a crucial element to the PHUL concept: speed work on hypertrophy days.
Structure: 5 Days/Week
| Day | Focus |
|---|---|
| Monday | Upper Power |
| Tuesday | Lower Power |
| Wednesday | Rest |
| Thursday | Back/Shoulders Hypertrophy |
| Friday | Lower Hypertrophy |
| Saturday | Chest/Arms Hypertrophy |
The Speed Element
On hypertrophy days, Norton starts with speed sets of the main lift: 6×3 at 65-70% of 1RM, performed explosively. The idea: train strength quality every day, even when the main focus is hypertrophy.
Explosive training improves Rate of Force Development (RFD) — the speed at which you can produce force. This is particularly relevant for powerlifters.
PHAT vs. PHUL
| Aspect | PHUL | PHAT |
|---|---|---|
| Days/Week | 4 | 5 |
| Speed Work | No | Yes (6×3 explosive) |
| Split | Upper/Lower | Upper/Lower + Body-Part Split |
| Creator | Community | Layne Norton (PhD) |
| Duration/Session | 60-75 min | 75-90 min |
| Ideal for | Intermediates, 4 days available | Intermediate+, 5 days, bodybuilding focus |
Scientific Evaluation
Volume: Evidence-Aligned
Both programs generate ~12-20 sets per muscle group per week — the sweet spot for hypertrophy. Not as extreme as nSuns (25+ pressing sets), not as little as StrongLifts (4-7 upper body sets).
Frequency: 2×/Week — Optimal
Each muscle group is trained 2× per week: once power (strength focus), once hypertrophy. 2×/week is substantially better than 1× for hypertrophy.
DUP: Scientifically Grounded
The core feature — varying rep ranges within the week — has solid evidence. DUP produces at least equal, often superior strength and hypertrophy results compared to linear periodization. Both heavy and light loads produce hypertrophy — varying both is optimal.
What’s Missing
- No built-in deload — you need to add one every 4-6 weeks yourself
- No autoregulation — fixed set/rep prescriptions, no AMRAP like Greyskull or 5/3/1
- Progression unclear — unlike LP programs, there’s no defined progression mechanism
Who Is PHUL/PHAT Suited For?
Ideal for:
- Intermediates (6-18 months of experience) — LP no longer works, but you want to keep growing
- Trainees who want both strength AND aesthetics — the DUP format serves both
- 4 days/week available (PHUL) or 5 days (PHAT)
- PPL too time-intensive — PHUL offers similar frequency in fewer days
Not ideal for:
- Beginners — use linear progression (GZCLP, Greyskull)
- Only 3 days/week — go with full-body or 5/3/1
- Pure strength focus — powerlifting-specific programs (5/3/1, nSuns) are more effective
Comparison with Alternatives
| Aspect | PHUL | PHAT | PPL | 5/3/1 |
|---|---|---|---|---|
| Days/Week | 4 | 5 | 6 | 3-4 |
| Focus | Strength + Hypertrophy | Strength + Hypertrophy + Speed | Hypertrophy | Strength |
| DUP | Yes | Yes | No | No (cycled) |
| Isolation | Moderate | High | High | Low |
| Periodization | DUP | DUP + Speed | None | 4-week cycles |
| Duration/Session | 60-75 min | 75-90 min | 60-75 min | 45-60 min |
PHUL in hitPR
PHUL gives you the framework — 4 days, power and hypertrophy separated, exercise selection set. What you need to bring yourself: a progression that fits both day types. In the hitPR PHUL plan, this runs on double progression — power exercises climb from 3 to 5 reps before weight goes up, hypertrophy exercises from 8 to 12. Three failures at the top end → 10% reduction, start building back up.
If four days stop being enough, the same principle exists across six: Power & Hypertrophy Advanced — two power days, four hypertrophy days.
Conclusion
PHUL and PHAT are excellent options for intermediates who want to build both strength and muscle size. The DUP principle is scientifically grounded — varying the rep scheme within the week produces superior adaptations.
PHUL is the more time-efficient variant (4 days), PHAT the more comprehensive (5 days with speed work).
References
- Rhea MR et al. (2002). A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength. JSCR, 16(2):250-255.
- Zourdos MC et al. (2016). Modified Daily Undulating Periodization Model Produces Greater Performance Than a Traditional Configuration in Powerlifters. JSCR, 30(3):784-791.
- Newton RU, Kraemer WJ (1994). Developing Explosive Muscular Power: Implications for a Mixed Methods Training Strategy. S&C Journal, 16(5):20-31.
- Schoenfeld BJ, Ogborn D, Krieger JW (2016). Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy. Sports Medicine, 46(11):1689-1697.
- Schoenfeld BJ, Ogborn D, Krieger JW (2017). Dose-response relationship between weekly resistance training volume and increases in muscle mass. J Sports Sciences, 35(11):1073-1082.
- Schoenfeld BJ et al. (2021). Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum. Sports, 9(2):32.
