Whether you’re a runner who logs serious mileage or a lifter who likes to pile on the plates, chances are you’ve dealt with achy knees at some point. And while loads of active people can commiserate about knee pain, the company doesn’t make the discomfort any more bearable.

Since your knees are actually the biggest joints in your body (and among the most complex, too), it’s no wonder issues with them are so common. Before you chalk your aches up to simply having “bad knees,” though, be on the lookout for some of these common lifestyle factors that are like the express lane to pain. (Don’t worry, we’ve got you covered on how to keep these important joints happy, too.)

• ABOUT OUR EXPERTS: Dr. Jasmine Marcus, P.T., D.P.T., C.S.C.S., is a physical therapist and strength and conditioning specialist. Rachel MacPherson, C.P.T., is a personal trainer and a pain-free performance specialist at Garage Gym Reviews. Adam Cardona, L.M.T., C.P.T., is a personal trainer and licensed massage therapist with Elite Healers Sports Massage.

1. You Ramped Up Your Running Routine Too Quickly

Recently decide to go all-in on your bucket list dream of running a marathon? It’s no wonder you’re hurting! Often, knee pain in runners is a symptom of something called tendinopathy, which is a tendon injury that results from overuse, explains physical therapist Dr. Jasmine Marcus, P.T., D.P.T., C.S.C.S. The symptoms are pretty wide-ranging and include burning, stiffness, swelling, and a crackling sensation when you move your knee. Often, tendinopathy is triggered when you suddenly begin running greater distances, start running at a greater speed, or switch from running on trails to on pavement.

“People have a hard time preventing and treating [tendinopathy] because they think they need to find the perfect shoe or the perfect stretch,” Marcus says. “But really that type of injury (and most running injuries) comes from overdoing it.” 

The fix: When you’re looking to up your distance or speed, do so gradually, Marcus says. Admittedly, this can be tricky because there’s no “good rule of thumb”, she admits. However, the Journal of Orthopaedic & Sports Physical Therapy reported that a sudden increase in weekly running distance by more than 30 percent could put you at risk for running-related injuries. So, if you’re ramping up your training, definitely take it slower than that.

2. Your Glute And Hip Strength Need Work

Interestingly, one of the most common root causes of knee issues has nothing to do with your knees at all. As it turns out, weak glutes and hips are some of the top culprits behind knee pain, explains Rachel MacPherson, C.P.T., a pain-free performance specialist at Garage Gym Reviews.

While weak glutes often stem from lack of exercise (particularly lack of strength training), they can also be the result of an imbalanced routine or an injury, she notes. Meanwhile, weak hip flexors (which are located in the front of your hips) can lead to weak gluteus medius muscles, which allow your upper legs to rotate inward, which then puts strain on your knee joint, she explains. Unfortunately, these weaknesses can put you at risk of ACL injuries.

Read More: Signs You Have Weak Glutes—And How To Strengthen Them

Something else to note: Weak glutes and hips that lead to knee pain tend to be more common in women, since they have a larger Q angle, which is the angle from the knee to the pelvis, thanks to proportionally wider hips, MacPherson notes.

The fix: If you suspect weak glutes and hips are raining on your parade, work with a personal trainer or physical therapist to incorporate more strengthening exercises into your regimen. Seeking help from a professional is particularly important if you’re experiencing a lot of knee pain and you are unconditioned. However, if you are cleared for exercise and are already relatively fit and experienced with lifting weights for a while, incorporate exercises such as bench step-ups, Bulgarian split squats, walking lunges, lateral lunges, squats, sumo deadlifts, and glute bridges to your strength-training program.

3. You Neglect Warm-Ups And/Or Stretching

Skimping on your warm-ups before training sessions or sitting for long periods without stretching and moving around can cause knee pain that primarily resides in the kneecap, which is known as “patellofemoral pain syndrome,” according to MacPherson.

Without ample movement throughout the day and before intense training, “your kneecap can’t move around the way it should because the soft tissues around it aren’t flexible or the surrounding muscles are weak,” she explains. “Tight tissues pull your kneecap in a specific direction, while weak muscles don’t allow it to move correctly.”

The result? You guessed it: pain. Again, thanks to that larger Q angle, women are particularly prone to patellofemoral pain syndrome.

The fix: Before hitting it hard at the gym, make sure you warm up with dynamic exercises and bodyweight movements that mimic what you will do during your training session, advises MacPherson. That means bodyweight squats if you plan to do weighted squats. 

If you work at a desk, taking breaks from sitting every 30 minutes to move around throughout the day is crucial, she adds. 

4. You Don’t Eat Enough Fruits and Veggies

Curious about what fruits and veggies have to do with knee pain? As it turns out, all kinds of essential nutrients promote joint health, many of which you’ll find in fruit and veggies, says Avery Zener, R.D., a dietitian at EverFlex Fitness. In fact, one study published in The Journal of Nutrition, Health, and Aging showed that eating fruits and veggies helped reduce knee pain in older adults.

The fix: Eat the rainbow! Doing so ensures you’re getting in some of the most important nutrients for joint health.

One example: the antioxidant vitamin C, which “is important for the production of collagen, a crucial structural component of the ligaments and tendons that make up our joints,” Zener says. Strawberries, broccoli, bell peppers, guava, oranges, and many other fruits and vegetables are loaded with vitamin C.

Lutein and zeaxanthin, types of phytochemicals known as carotenes that contribute to the yellow or orange color of some veggies and fruits, are also big for healthy knees, Zener shares. In fact, they’re associated with a reduced risk of cartilage damage, which is a fundamental tissue for knee joint health.

Zener also recommends incorporating omega-3 and curcumin (the antioxidant in turmeric) supplements, both of which work to support healthy joints.

5. You’re Overtraining

Casual joggers and marathon runners are probably familiar with “runner’s knee,” which refers to pain that comes from overuse of and inflammation in the tendon that attaches your quad to your patella (i.e. knee cap), MacPherson explains. 

Read More: 6 Signs You’re Suffering From Exercise Burnout—And How To Shake It Off

Though its name suggests it’s specific to runners, runner’s knee can be triggered by walking, jumping, cycling, or any sport or activity (yup, lifting, too!) in which you repetitively bend and straighten your knee, she points out. One of the biggest culprits behind this type of knee pain: overtraining.

The fix: Ensure that you take enough days off between your training sessions, MacPherson recommends. Obviously, it’s always a good idea to plan a few days in between your leg workouts. In addition, it’s possible that certain exercises that tend to aggravate your joints simply need to be cut from your program. Common offenders here include leg curls or leg extensions, which put a lot of strain on the knees, she says. Forcing super-deep squats is also a recipe for knee pain, so stick with whatever depth works for your anatomy and don’t worry if your knees extend out past your toes when you drop down.

6. Your IT Band Is Angry

If you start to feel aches and pains on the outer side of your knee that sharpen the more you exercise, the issue could be “iliotibial band syndrome.” There are a few theories behind this overuse injury, including inflammation under the IT band and chronic inflammation of the IT band itself, according to the Hospital for Special Surgery. It’s most common amongst runners and cyclists but is also seen in those who play basketball, ski, or play soccer.

The fix: Treatment options may vary here, but they typically involve rest, physical therapy, and a carefully designed strength training plan, as well as strategic stretching. 

In fact, massaging your glutes on a regular basis can help relieve strain on the IT band, says trainer and massage therapist Adam Cardona, L.M.T., C.P.T., with Elite Healers Sports Massage. Foam rolling can also bring some relief. Just how often you need to show your glutes some TLC depends on individual factors, so check in with a professional to figure out what makes sense for your needs.