The 5 laws of strength training are: build joint mobility, strengthen tendons and ligaments, develop the core, train the small stabilizing muscles, and train movements rather than single muscles. Follow them in roughly that order and you build a body that can handle heavy loads. Skip them, and strength gains often end in injury.
However, most people who get hurt lifting don’t get hurt because strength training is dangerous. They get hurt because they built strength faster than their joints, tendons and trunk could support it. In more than 30 years of coaching in San Diego, from teenage athletes to clients in their 70s, I’ve seen the same pattern over and over. The fix is a simple set of rules.
The framework below comes from sports scientist Tudor Bompa, widely known as the father of periodization, who described five basic laws of strength training in his work on planning athletic training. What follows is my own explanation of those ideas and how I apply them with clients every week.
What are the 5 laws of strength training?
- Develop joint mobility before loading a full range of motion.
- Develop tendon and ligament strength before chasing maximum muscle strength.
- Develop core strength before loading the arms and legs heavily.
- Develop the stabilizers that keep joints centered under load.
- Train movements, not individual muscles.
In short, each law protects the one after it. Mobility lets you reach good positions. Strong connective tissue handles the load. A strong core transfers force. Stabilizers keep joints on track. Movement training ties it all together.
Law 1 of the 5 laws of strength training: develop joint mobility
Almost every big lift uses a large range of motion at the ankles, knees, hips and shoulders. If a joint can’t reach a position comfortably, your body finds it somewhere else, usually by rounding the lower back, letting the knees cave, or arching to get the arms overhead. That’s where strain and pain start.
Ankles deserve special attention. Stiff ankles are one of the most common reasons people can’t squat deeply with a tall chest. For example, if your heels lift or your torso tips far forward in a bodyweight squat, ankle mobility is a likely culprit.
How to apply it:
- Start every session with a dynamic warm-up that moves your ankles, hips and upper back.
- Use drills such as knee-to-wall ankle rocks, deep goblet squat holds, hip openers and thoracic rotations.
- Only load a range of motion you can already control without weight.
Law 2: Develop tendon and ligament strength
Muscles adapt quickly to training. However, tendons and ligaments adapt much more slowly. As a result, many people feel strong enough to lift heavy within a few weeks, but their connective tissue isn’t ready yet. That gap is a classic setup for tendon pain in the knees, elbows, Achilles and shoulders.
Bompa calls the early foundation phase “anatomical adaptation.” In plain terms, you spend several weeks with moderate weights and more reps, so tendons and ligaments can catch up before you push intensity.
How to apply it:
- Spend roughly 4 to 8 weeks at moderate loads (about 10 to 15 reps) when you’re new or returning from a break.
- Use controlled tempos, especially on the lowering phase.
- Increase load gradually; read my guide to progressive overload.
- Be patient with jumping and plyometrics, which load tendons hard.
Law 3: Develop core strength
Your arms and legs can only be as strong as the trunk they attach to. For example, a weak core is like firing a cannon from a canoe. The core also acts as a shock absorber when you land, change direction or carry heavy loads.
That’s why a strong core isn’t about endless crunches. Instead, it’s about resisting unwanted movement: keeping your spine steady while your arms and legs work.
How to apply it:
- Learn to brace before every lift; see my post on breathing and bracing.
- Train anti-extension (planks, dead bugs), anti-rotation (Pallof presses) and anti-lateral flexion (side planks, suitcase carries).
- Build core endurance first, then add load.
Law 4: Develop the stabilizers
Big muscles like the quads, glutes, chest and lats move the weight. Smaller stabilizers keep your joints centered while they do it. Think of the rotator cuff around the shoulder, the deep hip muscles that control your knees, and the muscles around your shoulder blades. So when stabilizers are weak, the prime movers pull joints out of position and injuries follow.
How to apply it:
- Include single-leg work such as split squats, step-ups and single-leg Romanian deadlifts.
- Add rotator cuff and shoulder blade exercises; here are my favorite rotator cuff exercises.
- Use lighter loads with strict control, because stabilizers respond better to precision than to heavy weight.
Law 5: Train movements, not individual muscles
In sports and daily life, muscles never work alone. Lifting a suitcase, climbing stairs or swinging a golf club uses many muscles in a coordinated pattern. So your program should train those patterns.
For that reason, the core movement patterns I build every program around are the squat, hinge, push, pull, lunge and carry. Isolation exercises like curls still have a place, but they’re the accessories, not the foundation. For workout ideas, see my functional training workouts.
How to use the 5 laws of strength training in a plan
Bompa’s larger idea is periodization: planning training in phases instead of improvising workout to workout. Here’s a simplified version of how I sequence the 5 laws of strength training for most clients:
| Phase | Typical length | Focus | Laws emphasized |
|---|---|---|---|
| Foundation | 4 to 8 weeks | Mobility, moderate loads, higher reps, core and stabilizers | 1, 2, 3, 4 |
| Strength | 6 to 12 weeks | Heavier compound lifts, lower reps, steady progression | 5, while maintaining 1 to 4 |
| Power or performance | 4 to 8 weeks | Faster movements, jumps or sport-specific work, if goals require it | All five |
Most adults don’t need a power phase at all. However, everyone benefits from the foundation phase, and returning to it after a layoff or injury is smart. For general targets, the CDC recommends muscle-strengthening activity at least 2 days a week for adults.
Do the 5 laws of strength training apply to older adults?
Absolutely. In fact, they matter even more after 40, because connective tissue adapts more slowly with age and joint stiffness is more common. The laws are the same. Instead, the foundation phase is simply longer and progress is more gradual. I cover this in more detail on my page about personal training for adults 40+, 50+, 60+ and 70+. If you’re just starting out, read my strength training for beginners guide, which includes a simple starter workout.
Common mistakes that break the laws
- Adding weight every session before tendons and technique are ready
- Skipping the warm-up and loading stiff joints
- Training only mirror muscles like chest and arms, while neglecting the back, hips and core
- Jumping into advanced programs or high-volume plyometrics too early
- Ignoring pain. Discomfort from effort is normal; sharp or joint pain is a signal to stop and get it checked by a medical professional
Apply the 5 laws with a San Diego coach
In the end, these laws are simple to read and harder to apply on your own, because it’s tough to judge your own mobility, form and readiness to progress. In my private studio in Bay Park, every one-on-one program follows the Chris Keith Method, which starts with an assessment and builds the foundation before we chase heavier numbers.
Want a strength plan that keeps you healthy for the long run? Text Chris at (619) 840-9099 for a free consultation, or contact Chris.
Related reading: Sore After Working Out? What’s Normal and What Helps · Intermediate Workout Plan: A Simple 14-Day Program That Works
Frequently Asked Questions
Have a question that isn’t covered here? See the full personal training FAQ.
What are the 5 basic laws of strength training?
The five laws, described by sports scientist Tudor Bompa, are: develop joint mobility, develop tendon and ligament strength, develop core strength, develop the stabilizing muscles, and train movements instead of individual muscles. Together they help you build strength without injury.
Why do tendons need more time than muscles?
Muscles respond to training within weeks, while tendons and ligaments remodel much more slowly. Spending several weeks at moderate loads lets connective tissue catch up, which lowers the risk of tendon pain when you start lifting heavier.
How long should the foundation phase last?
For most beginners or people returning from a break, about 4 to 8 weeks of moderate loads, higher reps and core and stabilizer work is a good start. Older adults or those coming back from injury may benefit from a longer foundation.
Do athletes and non-athletes follow the same laws?
Yes. The laws apply to everyone who lifts. Athletes may progress to power and sport-specific phases, while most adults stay focused on the foundation and strength phases for health, function and injury prevention.
Chris Keith has over 30 years of personal training in San Diego (since 1995) and was voted Best Personal Trainer by San Diego Magazine. He trains clients one-on-one at his private studio in Bay Park. Learn more about Chris or contact Chris to get started.
