Back pain and knee pain are the most common complaints I hear from people over 40 (sometimes even in the 30s these days).
They blame age. They blame genetics. They blame old injuries, bad luck, or just “getting older.”
Most of them are wrong.
The research points to something simpler—and more fixable.
Two muscle groups, when weak, predict pain.
When strong, they prevent it.
Your core and your quads.
What the Research Says About Core Strength and Back Pain
Back pain affects up to 80% of adults at some point in their lives.
It’s one of the leading causes of disability worldwide. And for most people, there’s no clear diagnosis—just pain.
The research on what helps is surprisingly consistent: core strengthening works.
A systematic review examining multiple randomized controlled trials found that core stability exercises resulted in lower pain ratings, improved function, and better muscular control in patients with chronic low back pain. Every study reviewed showed improvement.
Another study published in the Journal of Physical Therapy Science found that a core exercise program significantly decreased pain scores both at rest and during movement, while increasing range of motion in the trunk.
The mechanism is straightforward. Your core muscles—particularly the deep stabilizers like the transversus abdominis and multifidus (I probably won’t remember these after writing this article)—provide stability to your spine. When these muscles are weak or don’t activate properly, your spine lacks support. Load gets transferred to structures that weren’t designed to handle it. Pain follows.
Researchers found that core strengthening works by recreating normal muscle function, increasing spinal stability, improving neuromuscular control, and preventing the shear forces that cause injury to the lumbar spine.
The conclusion from the research: core strengthening is an effective rehabilitation technique for chronic low back pain, regardless of how long someone has been suffering.
What the Research Says About Quad Strength and Knee Pain
Knee pain tells a similar story.
A large study using data from the National Health and Nutrition Examination Survey analyzed over 2,600 adults. The finding was striking: for every increase in quadriceps strength, the odds of knee pain decreased.
People in the highest quartile of quad strength had 72% lower odds of knee pain compared to those in the lowest quartile.
The relationship followed an L-shaped curve—meaning the biggest benefits came from moving out of weakness.
Going from weak quads to moderately strong quads made the most difference.
A randomized clinical trial found that an eight-week quadriceps strengthening program was effective in improving pain, function, and quality of life in patients with knee osteoarthritis.
The American College of Rheumatology now recommends strength training to manage symptoms of knee osteoarthritis.
I can attest. In my current PT sessions we are focusing exclusively on building quad strength, and I’ve already noticed considerable differences in the way my knees (AND GLUTES) feel.
Another study found that after just five weeks of isometric quadriceps exercises, patients showed significantly greater reductions in pain intensity and improvements in function compared to a control group that did nothing.
Perhaps most importantly, a 30-month study found that subjects with greater quadriceps strength had less knee pain, better physical function, and were even protected against cartilage loss over time.
The quads aren’t just about pain management. They’re about joint protection.
Why Most People Get This Backwards
Here’s what I see constantly:
Someone’s back starts hurting. They rest. They avoid movement. They let the core weaken further. The pain gets worse.
Someone’s knee starts hurting. They stop squatting, stop lunging, stop doing anything that loads the quads. The muscles atrophy. The pain intensifies.
Rest feels logical. Movement feels risky. But the research says the opposite: strategic strengthening of these specific muscle groups is one of the most effective interventions available.
The muscles that support the joint need to be strong for the joint to function without pain. Weakness creates instability. Instability creates compensation. Compensation creates pain.
The Prevention Nobody Talks About
Most people wait until pain arrives before they think about core or quad strength.
That’s backwards.
The same mechanisms that help rehab an injury can prevent one from happening in the first place.
Strong core before your back starts hurting = a spine with proper support and stability.
Strong quads before your knees start aching = joints with muscular protection and shock absorption.
The people I’ve watched age well—the ones still moving freely in their 60s, 70s, and beyond—almost always have two things in common: they maintained core strength and they maintained leg strength.
They didn’t wait for pain to motivate them. They built the armor before they needed it.
What Actually Works
For your core:
Dead bugs, planks, bird dogs, and side planks build the deep stabilizers without putting stress on your spine.
What I use? Planks and 8 Minute Abs (the famous youtube workout). That’s literally it. If I’m feeling lazy, I do ab machines, but I don’t think these truly build ab strength as much as building a 6 pack aesthetic. I do ab exercises anywhere from 3-5 times per week.
Unlike crunches, which load the spine in flexion, these exercises train stability—which is what your core is actually designed to provide.
Consistency matters more than intensity.
Research shows that even moderate core training, done regularly, produces significant improvements in pain and function.
For your quads:
Squats, lunges, step-ups, and leg extensions all build quad strength effectively. Isometric exercises—like wall sits or simply squeezing your quads with your leg straight—are particularly good for people already experiencing knee pain, as they strengthen without requiring much joint movement.
What I’m focusing on? Building strength with tempo work, which will take some time as my quads became really weak over time from improper training. I train legs 3-4 times a week. Double on one day, which is a PT session.
The research used protocols of three to five sessions per week.
But even daily bodyweight squats and lunges, done consistently, will build the strength that protects your knees.
The 10-Minute Insurance Policy
You don’t need an hour in the gym to protect your back and knees.
A simple daily routine:
For your core (5 minutes):
- Dead bugs: 1 minute
- Plank: 1 minute
- Side plank (each side): 1 minute each
- Bird dogs: 1 minute
For your quads (5 minutes):
- Bodyweight squats: 2 minutes
- Lunges (alternating): 2 minutes
- Wall sit: 1 minute
That’s it. Ten minutes. No equipment. Anywhere.
Done daily, this builds the muscular support your back and knees need to function without pain. The research supports it. The people who age well have been doing some version of it for decades.
The Choice
You can ignore your core and quads until pain forces you to pay attention.
Or you can build them now, while it’s easy, while it’s preventive, while it takes ten minutes instead of months of rehab.
Back pain and knee pain aren’t inevitable consequences of aging. For most people, they’re consequences of weakness—weakness that’s entirely preventable.
The muscles exist. The research exists. The exercises exist.
The only question is whether you’ll use them before you need them, or after.
Your back and knees are sending signals right now. They’re either stable and supported, or they’re waiting for the load that finally breaks through.
Ten minutes a day decides which one.
Today’s FL10 Minute Workout: High Achiever
10 min · No gym · No equipment · 2 min each
- Tempo Squats (3 seconds down, 3 seconds up)
- Tempo Push-Ups (4 seconds down, pause, 2 seconds up)
- Tempo Lunges (3 seconds down, 1 second hold, 2 seconds up)
- Tempo Glute Bridges (2 seconds up, 3 second hold at top, 3 seconds down)
- Tempo Calf Raises (2 seconds up, 2 second hold, 4 seconds down)