Tendonitis strength training means loading a sore tendon on purpose, slowly and progressively, instead of resting it until the pain fades. For most people with lingering tendon pain in the knee, Achilles, elbow, hip or shoulder, tendon experts now favor gradual, monitored strength work over complete rest. As a result, the goal is to rebuild what the tendon can handle.

I’m Chris Keith, and I’ve had over 30 years of personal training in San Diego. In that time, tendon pain is one of the most common reasons adults walk into my Bay Park studio after their physical therapy ends.

Tendonitis strength training guide: Chris Keith training with battle ropes in his private Bay Park studio in San Diego

Is it tendonitis or tendinopathy?

For decades, slow-building tendon pain was called “tendonitis.” The “-itis” means inflammation, so the advice was rest, ice and anti-inflammatory pills. However, tendon research over the past few decades has shown that inflammation isn’t the whole story.

That’s why tendon experts now prefer a different word. In 2019, the ICON international tendinopathy consensus, published in the British Journal of Sports Medicine, recommended “tendinopathy” for persistent tendon pain and lost function related to loading. In other words, the problem is less about inflammation and more about a tendon that can no longer handle the loads you ask of it.

Most people still search for “tendonitis,” so I use both words here. Either way, the practical takeaway is the same: the tendon needs the right amount of load, not zero load.

Why doesn’t rest fix tendon pain?

Rest calms symptoms for a while. However, it also lowers what the tendon can tolerate. So when you go back to running, golf, tennis or lifting, the same activity can feel too hard again.

Many of my clients describe the same cycle before they come to me:

  • Boom: a spike in activity, such as a long hike at Torrey Pines or a weekend tennis tournament, brings on pain.
  • Bust: they rest completely until the pain goes away.
  • Repeat: then the pain returns with even less activity, so they rest again.

Over months, that cycle shrinks what they can do. In fact, research supports staying active with a plan. In a 2007 randomized trial by Silbernagel and colleagues in the American Journal of Sports Medicine, people with Achilles tendinopathy who kept running and jumping, guided by a pain-monitoring model, did just as well as those who stopped those activities for six weeks. Both groups followed the same progressive strengthening program and improved.

How does tendonitis strength training work?

Tendonitis strength training slowly raises how much load the tendon, the muscle and the whole limb can handle. Also, it raises your confidence to move again. Programs usually progress through four overlapping stages:

Stage What it looks like Example for a sore knee
1. Isometric holds Pushing against resistance without moving, for a few seconds at a time Wall sit or a held leg extension
2. Heavy, slow strength Slow lifts, often about 3 seconds down and 3 seconds up Squats, split squats, step-downs
3. Faster loading Jumping, landing and quicker movements Box jumps, hops, lunges with a step
4. Back to your activity Gradually rebuilding your sport or hobby Building running miles or court time back up

Keep in mind that these stages overlap. For example, you might still do isometric holds a few times a week while you add heavier lifts. Then, faster movements come in only when slow strength work feels solid.

The same idea applies to other tendons. For instance, heel raises load the Achilles, gripping and wrist exercises load the elbow, and side-lying or banded exercises load the hip and shoulder.

Is some pain okay during tendonitis strength training?

Often, yes. Many research programs allow a tolerable level of pain during exercise, as long as it settles. So the more useful question is how you feel the next morning.

Here’s the simple check I use with clients:

  • During exercise: pain stays at a level you’re comfortable with. For many people that’s around 3 to 5 out of 10.
  • Right after: pain is the same or better. Tendons often “warm up” and feel better with activity.
  • The next morning: pain is back to your usual level. If it’s clearly worse, you did too much, so we lower the load or the volume next time.

Also, progress isn’t only about the pain number. For example, if you go from one mile at a 3 out of 10 to three miles at the same 3 out of 10, that’s real progress. After all, the tendon now handles three times the work.

How long does tendon rehab take?

Usually longer than people hope. Tendons adapt slowly, so meaningful change often takes three months or more, and stubborn cases can take a year. That’s why patience and consistency matter more than any single exercise.

In addition, your overall health plays a part. Sleep, stress, nutrition, alcohol, smoking and daily activity can all affect how tendons recover. For example, simply walking more each day is a small change that supports the bigger plan.

What about injections, ice or massage?

Ice, foam rolling and massage are low-cost and low-risk, so they’re fine if they help you feel better. However, they don’t replace progressive loading.

Injections deserve a closer look before you decide, so discuss them with your doctor:

In short, there’s no quick fix. Steady, well-planned strength training remains the core of tendon rehab.

When should you work with a personal trainer for tendon pain?

First, see a doctor or physical therapist to confirm what’s going on, especially after a sudden injury, swelling, or pain that wakes you at night. A trainer doesn’t diagnose and doesn’t replace physical therapy.

Then, a trainer is most useful for the long middle stretch, after PT discharge, when you need to keep progressing for months. That’s exactly what my strength training after physical therapy program is for. In my private 1-on-1 sessions, we pick tendon-friendly exercises, track your next-day response, and adjust the load each week. Because many of my clients are in their 40s, 50s and 60s, my training for adults 40+, 50+ and 60+ builds this into a whole-body plan.

Clients come to the studio at 5260 Riley St in Bay Park from across San Diego. It’s a short drive from Clairemont, Point Loma, Pacific Beach, Mission Valley and Old Town. Sessions are 1 hour, by appointment only. You can see package prices on the rates page, or text Chris at (619) 840-9099 for a free consultation.

Also worth a read: 5 physical therapy mistakes to avoid, how to upgrade common rehab exercises and rotator cuff exercises for recovery.

Frequently Asked Questions

Should I stop exercising if I have tendonitis?

Usually not completely. Complete rest often eases pain for a while but lowers what the tendon can handle, so symptoms can return when you get active again. Instead, reduce the activities that clearly flare it up and keep loading the tendon with controlled strength exercises. Check with your doctor or physical therapist first, especially after a sudden injury.

How much pain is okay during tendonitis strength training?

Many programs allow mild, tolerable pain during exercise, often around 3 to 5 out of 10, as long as it settles afterward. The most important check is the next morning. If your pain is clearly worse than usual the day after, reduce the load or the number of sets next time.

What exercises help tendon pain?

Programs usually start with isometric holds, such as a wall sit for a sore knee or a held heel raise for the Achilles. Then they add slow, heavy strength exercises like squats, split squats and step-downs. Finally, they add faster movements and a gradual return to sport. The right choice depends on which tendon is involved.

How long does it take for a tendon to heal?

Tendons adapt slowly, so improvement often takes three months or more, and some cases take a year. Progress isn’t always a straight line, and pain can go up and down from week to week. Focus on what you can do over time, such as more weight, more miles or more time on the court.

Can a personal trainer help after physical therapy for a tendon injury?

Yes. A trainer can continue the progressive strength work after you finish physical therapy, while you keep your doctor or physical therapist informed. Chris Keith trains adults 1-on-1 at his private studio in Bay Park, San Diego. Text (619) 840-9099 for a free consultation.

Ready to get back to the things you love? Text Chris at (619) 840-9099 for a free consultation, or use the contact page.

This article is general information, not medical advice. If you have pain, swelling or an injury, see a doctor or physical therapist before starting a new exercise program.

Research and Guidelines Cited

Chris Keith has over 30 years of personal training in San Diego (since 1995) and was voted Best Personal Trainer by San Diego Magazine.