Stiff knees when you stand up? Achy hips after sitting too long? Shoulders that seem to complain more than they used to? While age-related changes in cartilage and other joint tissues can play a role, joint health is influenced by more than wear and tear alone.

Here are five common habits that may be contributing to stiffness or discomfort—and some simple ways to give your joints a little more support.

1. Spending Too Much Time on Your Phone at Night

A few minutes of scrolling before bed can easily turn into an hour.

Aside from keeping you in the same hunched-over position, nighttime screen use may interfere with sleep—especially when it pushes bedtime later or keeps your brain stimulated when it should be winding down.

And sleep matters for pain.

Research has found a relationship between poor sleep and increased pain sensitivity. In other words, when you aren't sleeping well, existing aches and discomfort may feel more noticeable.

Try this instead:

Consider giving yourself a 30- to 60-minute screen-free window before bed.

Use that time for something that helps your body transition toward sleep, such as gentle stretching, reading, listening to music, or preparing for the next day.

Getting regular daylight exposure during the day and maintaining consistent sleep and wake times can also help support your body's natural sleep-wake cycle.

2. Sitting for Long Stretches Without Moving

Whether you're working at a computer, reading, watching television, or settling in for a movie marathon, staying in one position for hours can leave joints feeling stiff.

Our bodies generally respond well to regular movement.

Short activity breaks can help you change position, engage your muscles, and break up long periods of sedentary time.

And those breaks don't need to become full workouts.

Try this instead:

Every 30 to 60 minutes, get up and move for a few minutes.

You might:

• Walk around the house or office
• Do a few gentle squats or sit-to-stands
• Stretch your shoulders and upper back
• March in place
• Walk up and down the hallway

Think of these as little movement snacks throughout your day.

A few minutes at a time can be much easier to fit into your routine than waiting until you have time for a long workout.

3. Doing the Same Movement for Too Long

Sitting still isn't the only issue.

Repeating the same movement or maintaining the same posture for extended periods can also leave muscles and joints feeling tired or uncomfortable.

Gardening, crafting, cleaning, cooking, sewing, working at a computer, and other everyday activities can involve surprisingly repetitive movements.

The goal isn't necessarily to stop doing them. It's to give your body some variety.

Try this instead:

Change positions regularly and pay attention to how you're holding your body.

If you've been bending over a garden bed, stand and walk around for a few minutes. If you've been crafting or typing, relax your hands and shoulders and change your position.

Alternating tasks can also help.

Instead of doing one physically repetitive activity for two straight hours, break it into shorter sessions and mix in activities that use your body differently.

4. Doing Cardio—but Skipping Strength Training

Walking is one of the simplest ways to stay active, and research suggests that regular walking may be beneficial for some people with knee osteoarthritis.

Running isn't automatically bad for your knees either. Evidence does not support the idea that recreational running inevitably causes osteoarthritis in otherwise healthy joints.

But cardio is only one part of a well-rounded exercise routine.

Strength matters, too.

Muscles help support and stabilize your joints. Because muscle mass and strength tend to decline with age, resistance exercise becomes increasingly important for maintaining mobility and everyday function.

Current U.S. physical activity guidelines recommend that adults get at least 150 minutes of moderate-intensity aerobic activity each week, along with muscle-strengthening activity on two or more days per week.

Try this instead:

Keep walking, cycling, swimming, or doing whatever cardiovascular activity you enjoy—but add some resistance work.

That could include:

• Bodyweight exercises
• Resistance bands
• Dumbbells or other weights
• Pilates
• Sit-to-stands
• Wall push-ups

You don't have to lift extremely heavy weights to benefit.

If you already have significant joint pain or a condition that affects movement, a physical therapist or other qualified healthcare professional can help determine which exercises are appropriate for you.

5. Wearing Unsupportive Shoes for Long Periods

Those old flip-flops might be fine for a quick trip outside, but they may not be the best choice for a long walk.

Your feet are the foundation for much of your movement, and footwear can influence how forces travel through the ankles, knees, hips, and lower back.

That doesn't mean everyone needs the same type of shoe.

Research suggests footwear recommendations can differ depending on the person and the joint involved. For example, supportive footwear may be helpful for some people with knee osteoarthritis, while the evidence is less straightforward for other types of joint pain.

Try this instead:

For longer walks, exercise, or activities that keep you on your feet, choose shoes that:

• Fit comfortably
• Are appropriate for the activity
• Feel stable under your feet
• Don't create new pressure points or discomfort

If persistent knee, hip, ankle, or foot pain is making footwear difficult to choose, a physical therapist, podiatrist, or other healthcare professional may be able to provide individualized guidance.

Small Changes Can Add Up

Joint discomfort doesn't always mean you need to stop moving. In many cases, regular movement and stronger supporting muscles are important parts of maintaining joint function as you age.

Instead of trying to overhaul everything at once, start small.

Take a two-minute walking break after sitting for a while. Put your phone away a little earlier tonight. Add a couple of basic strength exercises to your next walk. Wear supportive shoes when you know you'll be on your feet.

Those may sound like tiny changes—but healthy aging is often built on the small things we do consistently.

And if joint pain is new, severe, worsening, associated with significant swelling or injury, or interfering with everyday activities, talk with a healthcare professional rather than simply trying to exercise through it.