Why You Keep Flaring Up: Understanding Your Body's Capacity
Have you ever wondered why you can hike five miles one weekend but your body aches after a short walk the next? Or why an exercise that felt easy last month suddenly causes a flare-up? The answer often isn't that your body is "broken." It's that your body's current capacity—the amount of stress it can comfortably tolerate—changes over time. Understanding capacity can help you exercise more consistently, recover better, and reduce unnecessary setbacks.
It’s all about Symmetry, Strength and Capacity
According to the current published data available, the 3 most important ways to prevent injury or reduce injury risk with sports, recreation or working out are:
Symmetry
Symmetry refers to matching between sides. This is the #1 factor for injury risk with the validated screens available to physical therapists and studies related to determining factors that drive sports injuries. The elevated risk can be as high as 6 fold! To reduce your risk for injury or protect yourself from injury, there needs to be symmetry between all of your limbs.
Between your right and left arm
Between your right and left leg
Between the right side of your body and the left side of your body.
Functional Strength
Functional strength is your body's ability to produce and control force during the activities that matter most in your everyday life. It's not simply about how much weight you can lift—it's about how efficiently your muscles, joints, posture, breathing, and balance work together to complete a task safely and comfortably.
For example, carrying groceries, climbing stairs, getting up from the floor, hiking, gardening, lifting your child, or simply getting out of a chair all require functional strength. When your body moves efficiently, the workload is shared across multiple joints and muscle groups, reducing unnecessary stress on any one area.
Functional strength isn't built by exercising harder—it's built by moving well first, then progressively challenging your body over time. You don't fail because you're weak—you fail because you've exceeded your current capacity. Capacity can be built.
Capacity
Think of your body's capacity like a bucket. Every day, different stressors add water to that bucket:
Exercise
Illness
Long workdays
If the bucket overflows, your body lets you know through pain, fatigue, stiffness, or reduced performance.
Capacity is the amount of physical and mental stress your body can tolerate, recover from, and adapt to without becoming overloaded. Think of it as your body's "ability to handle life."
Every day, your body experiences different demands, including:
Exercise
Work
Household activities
Stress
Poor sleep
Illness
Nutrition
Recovery
Some days your capacity is high, allowing you to tolerate more activity. Other days, your capacity is lower, meaning the exact same workout or activity may leave you feeling sore, fatigued, or experiencing a pain flare-up.
The goal isn't to avoid challenging your body—it's to challenge it just enough that your body adapts and becomes stronger over time.
Functional Strength Builds Capacity
Functional strength and capacity work together.
As your movement becomes more efficient, your muscles become stronger, and your cardiovascular fitness improves, your body becomes better at distributing and tolerating physical loads. Over time, this increases your capacity, allowing you to participate in more activities with less fatigue, fewer flare-ups, and greater confidence.
This is why exercise should be progressed gradually. Following evidence-based exercise guidelines helps provide enough challenge for your body to adapt while allowing adequate recovery between sessions. Paying attention to your body's response—using the Soreness Rules to guide your training decisions—helps you determine when you're ready to progress and when your body would benefit from additional recovery.
High-intensity interval training (HIIT), strength training, walking, and everyday movement can all improve capacity when they're matched to your current abilities and progressed appropriately. The objective isn't to do the hardest workout possible—it's to consistently perform the right amount of activity so your body becomes more resilient over time.
When you combine healthy movement, progressive strengthening, appropriate recovery, and consistent activity, you're not just building stronger muscles—you're building a body that's better prepared for everything life asks of it.
Capacity Self Test
When in a plank, can you reach forward evenly between your right and left arms? The difference in your reach needs to be less than 4 centimeters (1.5 inches)
When in a plank, can you reach forward with one hand to that target distance without moving out of the alignment of your starting position?
When in a plank, can you reach forward with one arm and then the other while maintaining a neutral spine, without collapsing or shifting to one side or the other?
Measure the length of your foot. Multiply that number by 2. That is the target distance for you to be able to reach with both of your arms and your legs in the reach test.
When in a standing on one leg, can you reach forward evenly between your right and then left foot? The difference in your reach needs to be less than 4 centimeters (1.5 inches)
When standing on one leg, can you reach forward with one leg and then the other without leaning to one side, losing your balance, or your knee collapsing inward or turning your foot out?
When standing on one leg, can you reach forward with the other foot to that target distance without moving out of the alignment of your starting position?
What Affects Your Capacity?
Sleep
Nutrition
Stress
Recovery
Previous injuries
Fitness level
Illness
Hormones
Workload
Putting It All Together
Building your body's capacity isn't about pushing through pain or simply exercising more. It's about finding the right balance between challenging your body and allowing it to recover and adapt. As your movement becomes more efficient and your strength and endurance improve, your capacity gradually grows—allowing you to do more with less discomfort and fewer setbacks.
If you're wondering what your next step should be, these resources can help:
Not sure if you're ready for today's workout? Learn how to use the Soreness Rulesto decide whether your body is ready to progress, modify your workout, or take a recovery day. Strength training is only as effective as your movement quality. Poor posture and body mechanics can overload joints and limit results. Learn Better Movement →
Ready to improve your fitness? High-Intensity Interval Training (HIIT) can be an excellent way to build cardiovascular fitness and strength when it's introduced gradually and matched to your current capacity. Learn the movement strategies that help you build strength, improve endurance, and increase your capacity for everyday life.
Wondering how much exercise is enough? My guide to the American College of Sports Medicine (ACSM) exercise recommendationsexplains how often to exercise, how many repetitions to perform, and how to safely progress your workouts over time.
Want to increase your capacity from the ground up? The Healthy Movement Rebootteaches the posture, breathing, and movement principles that help your body move more efficiently. When your muscles and joints work together more effectively, your body can often tolerate more activity with less pain, fatigue, and strain.
Building Capacity with Hypermobility
If you have hypermobile Ehlers-Danlos syndrome (hEDS) or a hypermobility spectrum disorder (HSD), building capacity often requires a different approach. Because your connective tissues provide less passive stability, your muscles have to work harder to support your joints during everyday activities. This means your body may fatigue more quickly, become sore more easily, or experience flare-ups when activity increases too rapidly.
The goal isn't to avoid exercise—it's to build your capacity in a way that respects how your body functions. By improving posture, breathing, muscle coordination, and active joint stability, you can gradually increase the amount of activity your body can comfortably tolerate while reducing unnecessary stress on your joints.
If you're living with hypermobility and are ready to build strength with greater confidence, my Hypermobility Program provides a step-by-step approach designed specifically for people with hEDS and HSD. You'll learn how to improve movement efficiency, increase joint stability, and safely expand your body's capacity so you can participate in more of the activities you enjoy.
Remember, improving capacity is a gradual process. Small, consistent improvements in how you move, recover, and train add up over time, helping you build a stronger, more resilient body that's better prepared for the activities you enjoy.
