An Intro Fitness and Resistance Training Program (Phase 3 — Muscular Development/Hypertrophy) with Full-Body Splits

Before diving into programming specifics, it’s worth asking: why focus on muscular development at all? While a well-developed physique may be one goal, building skeletal muscle is about far more than aesthetics. Maintaining and increasing muscle mass contributes significantly to overall health, metabolic function, and longevity — especially as we age.

A 2014 study published in the American Journal of Medicine found that higher muscle mass was associated with a lower risk of all-cause mortality in older adults, even after adjusting for fat mass and other confounding variables (Srikanthan & Karlamangla, 2014). In other words, the more muscle you carry into your later years, the better your odds of living longer — and living well.

Skeletal muscle plays a central role in:

• Glucose regulation and insulin sensitivity

• Basal metabolic rate maintenance

• Mobility and injury prevention

• Bone density support

• Functional independence as we age

Muscle loss, known as sarcopenia, typically begins around age 30 and accelerates with inactivity or poor nutrition. Resistance training is the most effective intervention to slow, stop, and even reverse this process.

So whether your goal is performance, longevity, or simply feeling stronger and more capable in everyday life — building muscle should be a lifelong priority.

Photo by RDNE Stock project via Pexels.

What Is Muscular Development?

Muscular development, also known as hypertrophy, refers to the process of increasing the size of skeletal muscle through targeted resistance training. This growth occurs primarily through myofibrillar hypertrophy (increased contractile protein content) and sarcoplasmic hypertrophy (increased non-contractile elements like glycogen and fluid in the muscle cell). The result: thicker, fuller muscles and enhanced physique and strength capacity.

In the National Academy of Sports Medicine’s (NASM) Optimum Performance Training (OPT) model, Phase 3 — Muscular Development — follows the foundational endurance and strength-endurance phases. This stage places a heavier emphasis on progressive overload and volume to induce muscle fiber growth. Key training parameters include:

• Sets: 3–5 per exercise

• Reps: 6–12 per set

• Rest: 30–90 seconds between sets

• Intensity: 65–85% of your one-repetition maximum (1RM)(NASM, 2022)

This phase builds on the muscular coordination and stability developed in earlier phases by increasing both load and time under tension.

Why a Full-Body Split?

A full-body split involves training all the major muscle groups in a single workout. It’s particularly well-suited for beginners, time-constrained individuals, or those looking to build balanced strength and hypertrophy without training 5–6 days per week.

Other common split styles include:

• Push/Pull/Legs (PPL): Separates workouts into pushing (chest, shoulders, triceps), pulling (back, biceps), and leg days.

• Upper/Lower: Alternates between upper-body and lower-body focused sessions.

• Body Part/“Bro” Split: Targets a single muscle group per workout (e.g., chest on Monday, back on Tuesday, etc.).

While each has its merits, full-body splits offer the critical advantage of higher training frequency per muscle group, which research shows is a key driver of hypertrophy. Studies suggest that training each major muscle group at least twice per week optimizes muscle growth, compared to once-weekly sessions (Schoenfeld et al., 2016).

Philosophy Behind the “Big Six” Full-Body Program

The following sample full-body workout is structured around six compound exercises — movements that engage multiple joints and muscle groups. This approach maximizes efficiency, ensuring all major movement patterns are trained:

• Push (horizontal and vertical)

• Pull (horizontal and vertical)

• Lower-body hinge and squat patterns

Beginners should perform this workout 2–3 times per week on non-consecutive days. More advanced lifters can pair it with a second full-body workout featuring different compound lifts and isolation movements.

Important: Choose a weight that brings you close to muscular failure in each working set. The last 2–3 reps should feel challenging but doable with proper form.

Sample Workout: BIG SIX Compound Full-Body Routine

Warm-Up

• Cardio (5 min): Elliptical, bike, or light jog

• Static stretching (30 sec each): Calves, quads, hamstrings, chest, triceps, lats, shoulders

1. Barbell Back Squat

• Warm-up: Bodyweight air squats x12 or bar-only x8

• Working Sets: 3 sets of 8–12 reps

2. Romanian Deadlift (RDL)

• Warm-up: Bar-only x8

• Working Sets: 3 sets of 8–12 reps

3. Pullups (Parallel and Wide Grip)

• Warm-up: 5 reps (parallel grip), 3 reps (wide grip)

• Working Sets: 3 sets of 8–12 (parallel grip) + 3 sets of 8–12 (wide grip)

Progression Tip: Add weight via vest or dip belt once you can do 12 clean reps.

4. Incline Dumbbell or Barbell Bench Press

• Warm-up: Push-ups x10 or bar-only x8

• Working Sets: 3 sets of 8–12 reps

5. Barbell Bent-Over Row

• Warm-up: Bar-only x8

• Working Sets: 3 sets of 8–12 reps

6. Standing Overhead Press (Barbell or Dumbbells)

• Warm-up: Bar or light dumbbells x8

• Working Sets: 3 sets of 8–12 reps

Optional Isolation Add-Ons (For Intermediate Lifters)

Biceps

• Standing DB or EZ-Bar Curl: 3 sets of 8–12 reps

Triceps

• Choice of:

  • Dips: Bodyweight or weighted, 3 sets of 8–12

  • Lying Overhead Triceps Extension (EZ-Bar or Barbell): 3 sets of 8–12

Final Thoughts

Hypertrophy training is about consistent overload, sufficient recovery, and smart programming. This full-body workout offers a practical, scalable foundation for building muscle across all major groups while reinforcing movement proficiency and balance. As your training age increases, consider alternating full-body workouts, incorporating new movement patterns, and adding targeted isolation work.

References

• Srikanthan, P., & Karlamangla, A. S. (2014). Muscle mass index as a predictor of longevity in older adults. The American Journal of Medicine, 127(6), 547–553. https://doi.org/10.1016/j.amjmed.2014.02.007

• NASM Essentials of Personal Fitness Training (7th ed.). (2022). Jones & Bartlett Learning.

• Schoenfeld, B. J., Ogborn, D., & Krieger, J. W. (2016). Effects of resistance training frequency on measures of muscle hypertrophy: A systematic review and meta-analysis. Sports Medicine, 46(11), 1689–1697. https://doi.org/10.1007/s40279-016-0543-8

• American College of Sports Medicine. (2009). Progression models in resistance training for healthy adults. Medicine & Science in Sports & Exercise, 41(3), 687–708. https://doi.org/10.1249/MSS.0b013e3181915670