Post-Sickness Recovery: Rebuilding Endurance after Viral Fatigue

Rick Canning

Pain Flare-Ups Don't Mean You're Getting Worse

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Recovering from a viral illness can be a frustrating and uncertain process. Long after the acute respiratory symptoms pass, many people in Calgary find themselves sidelined by persistent physical exhaustion, shortness of breath during routine activities, and a lingering sense of fatigue. Tasks that used to feel effortless, like climbing a flight of stairs, walking the dog along the Bow River, or keeping up with a normal work routine, can suddenly feel like climbing a mountain.

At Vital Performance Care in Calgary, we frequently work with individuals navigating post-viral fatigue. Rebuilding cardiovascular endurance after sickness is not about pushing through the pain or jumping straight back into high-intensity workouts. Instead, safely restoring your stamina requires a structured, evidence-based approach that respects your body's energy limits, avoids symptom flare-ups, and gradually restores tissue capacity.

Rick’s Long Covid Story

Back in 2021 I got Covid and my life changed overnight. I was an Ultra Endurance athlete running 100 mile races in the mountains and instantly went from running 100 miles in a single push, to not being able to get off the couch and unable to even walk 1 kilometer. I also was unable to think clearly, not only was I forced to leave my job, but I was so bad that I couldn’t even figure out how to put dishes away while unloading the dishwasher.

What followed was years of debilitating symptoms, the hardest being not being able to participate in the sport I loved at the level I was used to. Realizing that in order to recover I had to stop forcing training to look like it used to and start focusing on allowing my nervous system to recover when everything shifted for me. Yes I still continued running, but I didn't force things when I wasn’t feeling good and I doubled down on HRV biofeedback breathwork training to retrain my nervous system.

Rebuilding endurance when you are deal with a host of post viral infection systems is not easy and it is not a linear process, but overtime if you are patient with yourself and are really honest with your true capacity (in all of life's tasks, not just training) while you are rebuilding you can make steady progress in rebuilding your endurance.

Understanding Post-Viral Fatigue and Exercise Intolerance

Post-viral fatigue is more than just feeling tired after a busy day. Viruses can affect multiple physiological systems simultaneously, impacting your autonomic nervous system, cardiovascular function, and cellular energy production.

When rebuilding endurance, the most critical factor to identify is whether you experience Post-Exertional Malaise (PEM) or Post-Exertional Symptom Exacerbation (PESE).

Post-Exertional Malaise (PEM): A disproportionate worsening of symptoms (such as extreme fatigue, brain fog, muscle pain, or sleep disturbances) that occurs 12 to 48 hours after physical, cognitive, or emotional exertion.
Standard Deconditioning: Feeling normal muscle tiredness or temporary breathlessness during or immediately after exercise, which improves steadily with rest and consistent training.

If you experience PEM, traditional "push-through-it" exercise programs can cause severe setbacks. Recovery requires a specialized management strategy focused on energy conservation before gradually increasing physical activity.

Heart Rate Variability (HRV) and VO2 Max Testing are the Keys to Understanding Your True Barriers to Recovery

HRV is the best way to get real time data on the state of your nervous system. No I am not talking about your HRV score that you get on your Garmin, Aura ring or Whoop. Those devices only give you one metric which can be used to chart a general trend but the real power of HRV measuring is so much more than that.

Using an accurate chest strap like a Polar H9 or H10 and a free app called Elite HRV you can go so much deeper into the raw data which is your nervous system health. This raw data tell us things like your day to day stress resistance, chronic stress load and your overall nervous system capacity to respond to stress and then recover from it.

This tool is a must have for anyone recovering from a post viral infection, and it is really empowering once you understand how to use it (or a coach like me collects your data and explains it all to you). This tool allows you to see on a day to day biases what interventions you are doing are moving the needle towards recovery and what is not working. It is truly a game changer.

HRV gets even better when you add this tool into Vital’s Breathing Foundations program. This program with a full metabolic assessment and a training plan to rebuild your lung function and nervous system capacity.

After completing a VO2 max test, along with your HRV you get a full picture of how your body is working and what your real limitations are to returning to sport. For me no amount of blood work, MRI’s or other tests were able to pick up on the real limitations that were holding back my recovery like this program did. Then the best part is that you get a plan to fix these limitations and you can measure your progress with HRV and retest your VO2 max. There is no guess work in understanding what is working, it is all measured and documented. If your symptoms of post exertion fatigue are really bad you can do a sub-maximal test on a bike which is way easier on the body and your nervous system. At a time when I was losing hope if I would ever revolver and be able to return to running this combination gave me my life back.

The 4 P's Framework for Rebuilding Endurance Safely

Rather than relying on rigid workouts, a post-sickness rehabilitation strategy uses structured pacing principles to help you manage your daily energy envelope.

Pacing: Listen to your body's early warning signals rather than waiting until your energy is completely drained. Stop activity while you still feel like you have reserve energy left in the tank.
Planning: Organize your day around your natural energy peaks. Spread physically demanding tasks (like grocery shopping or house cleaning) throughout the week rather than stacking them into a single day.
Prioritizing: Identify which daily activities are essential and which can be delegated, postponed, or simplified while your cardiovascular system recovers.
Positioning: Reduce the physiological workload on your heart and lungs by performing tasks in supported positions. For example, sitting down while preparing meals or folding laundry conserves valuable energy for your rehabilitation.

A Phased Progression for Cardiovascular Recovery

Once symptom stability is established, cardiovascular endurance can be safely rebuilt using a phased, step-by-step approach. Progression should always be based on how your body feels 24 to 48 hours after activity, rather than how you feel during the exercise itself.

Phase 1: Rest and Preparation

The primary objective during this initial stage is establishing a stable symptom baseline. Physical efforts focus on gentle daily mobility, diaphragmatic breathing exercises, and completing basic household activities without triggering fatigue spikes. Quality sleep, prioritizing hydration, and proper nutrition (limiting excess sugars and processed foods) are the key priorities before introducing formal exercise.

Phase 2: Low-Impact Movement

Once you can complete daily activities without post-exertional symptoms for at least two consecutive weeks, you can introduce short, low-impact movements. This typically involves 5 to 10 minute walks on flat surfaces or light stretching. The goal here is to keep your heart rate low and maintain easy, conversational breathing without gasping for air.

Phase 3: Interval Building

As short continuous efforts become comfortable, the focus shifts to interval training. This involves alternating brief periods of light movement (such as 2 to 3 minutes of walking) with equal or longer periods of structured rest. Using intervals allows your heart and lungs to adapt to higher physical demands while minimizing the risk of systemic exhaustion. Total daily movement time is gradually increased before adding any intensity.

Phase 4: Functional Endurance

The final phase focuses on returning to continuous cardiovascular activities and light resistance training. Walking times can be expanded to 20 or 30 minutes, and low-impact equipment like stationary bikes or ellipticals can be reintroduced. This phase prepares your body to safely return to pre-illness recreational activities, sports, and higher-demand daily tasks at your own pace.

Key Exercises to Restore Breathing and Stamina

Incorporating gentle, targeted movements helps retrain your respiratory muscles and rebuild basic functional stamina without overtaxing your nervous system.

Diaphragmatic Breathing (Belly Breathing)

Primary Goal: Retrain your primary breathing muscle (the diaphragm) to reduce chest tightness and lower sympathetic nervous system stress.
How to Do It: Lie comfortably on your back with your knees bent and feet flat. Place one hand on your upper chest and the other hand on your belly just below your ribcage. Breathe in slowly through your nose, feeling your belly expand gently under your bottom hand while your chest stays relatively still. Exhale slowly through pursed lips.
Target Duration: Practice for 3 to 5 minutes, 2 to 3 times daily.

Seated Recumbent Pedaling or Marching

Primary Goal: Reintroduce cardiovascular movement to the lower body without requiring upright balance control.
How to Do It: Sit in a supportive chair with your feet flat on the floor. Gently lift one knee at a time in a slow, controlled marching rhythm, keeping your breathing steady and relaxed. If available, a stationary recumbent bike or foot pedaler is an excellent low-impact alternative.
Target Duration: Perform 1 to 2 minutes of continuous gentle movement, rest for 1 minute, and repeat for 3 to 5 total sets.

Sit-to-Stands

Primary Goal: Rebuild functional strength in your large thigh and hip muscles to make daily walking and standing easier.
How to Do It: Stand with your feet placed hip-width apart. Slowly lower down into a moderate, yet, comfortable bend at your knees and sit down into a chair. Pause for 2 seconds, then push through your heels to return back up to standing.
Target Repetitions: 5 to 8 slow repetitions for 2-3 sets, ensuring you rest immediately if you feel lightheaded. Progress the exercise by aiming for repetitions in 30 second intervals with rest breaks in between.

Rebuild Your Endurance at Vital Performance Care

Recovering from post-sickness fatigue requires time, adaptability, and an individualized care plan. Trying to hurry the process often leads to frustrating cycles of overexertion followed by prolonged crashes. By respecting your body's pacing limits and gradually building capacity, you can safely restore your stamina and return to the activities you love.

Our physical therapy and endurance coaching team at Vital Performance Care in Calgary, AB, can assist in post-viral rehabilitation, cardiovascular conditioning, and personalized load management. Contact Vital Performance Care today to schedule your recovery assessment and take a confident, structured step toward rebuilding your energy.

More About The Author

Rick Canning

With a Bachelor in Engineering and coaching certifications in Marathon, Ultra running and Triathlon, Rick has brought a unique skill set to endurance coaching since 2015.

He specializes in finding practical solutions to complex problems while helping athletes go after big goals. Whether that is tackling a new distance, achieving a personal best or striving for qualifying standards and podium finishes.

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Introduction

"Oh, it's just part of getting older."

Cool, cool, cool. Except your shoulder used to work fine. You used to jump out of bed. You weren't rehabbing a new injury every other week. So no, this isn't just a normal part of aging, and it doesn't have to be something you just accept.

There's actually a clinical name for it: the musculoskeletal syndrome of menopause. It's our understanding of how the hormonal changes of perimenopause and menopause affect the musculoskeletal system, and how hormone therapy can be used to help treat these symptoms as part of a holistic approach to rehabilitation.

The same hormonal changes that cause our hot flashes, disrupted sleep, and make us not feel like ourselves are also directly impacting the tissue that lets you move: how your muscles repair themselves, how your joints handle load, how your tendons hold up over time, and how your bones maintain their density and strength.

This article breaks down what's actually happening in your body during perimenopause and menopause, why declining estrogen hits your musculoskeletal system so hard, and how a collaborative approach between hormone therapy and rehabilitation can improve your quality of life.

Not sure if hormones are behind your aches and pains?

A hormonal health consult with Pause Health can tell you whether hormonal changes may be part of the picture, and whether hormone therapy is appropriate for you. A movement assessment with Vital Performance Care tells you what's actually happening with your strength, mobility, and joints. The real answer often needs both.

Book a Hormone Consult with Pause Health

Book a Clinical Musculoskeletal Assessment with a Chiropractor or Physiotherapist at Vital Performance Care

What Is the Musculoskeletal Syndrome of Menopause?

The term was formally introduced in 2024 by orthopedic surgeon Dr. Vonda Wright and colleagues, in a review published in the journal Climacteric (Wright et al., 2024). It covers the cluster of musculoskeletal symptoms that show up as estrogen declines during perimenopause and menopause:

"Common doesn't mean normal, and it doesn't mean untreatable."

Why This Gets Missed

Imaging isn't always helpful here, and a normal scan doesn't mean nothing's wrong. It usually means a single joint in isolation isn't the whole story.

If you're in midlife dealing with shoulder pain, recurring tendon issues, stiffness, or a real drop in strength, the useful question isn't just "what's wrong with this joint." It's what else has changed:

All of it can be part of the same picture, and all of it is worth bringing up with your provider.

It's Not Only a Post-Menopause Problem

These changes often don't wait for your final period to show up. For a lot of women, this starts in perimenopause, while hormones are still fluctuating rather than non-existent. New stiffness, more frequent tendon flare-ups, muscle that's harder to maintain, an injury that seems to have come out of nowhere — these can all start years before menopause or the one-year anniversary of your last menstrual period.

That doesn't automatically mean hormones are the cause, but when it's happening alongside other perimenopause symptoms, it is worth considering the connection. Waiting until you're fully postmenopausal to start paying attention also means missing a window where building strength and addressing risk factors is a lot easier than trying to recover ground later.

How Estrogen, Progesterone, and Testosterone Affect Your Joints, Muscles, and Bones

Your musculoskeletal system is more hormone-sensitive than most people realize. Estrogen, progesterone, and testosterone receptors exist throughout your muscles, tendons, ligaments, cartilage, and bone. When those hormone levels shift, so does the health of every one of those tissues.

Estrogen: The Primary Driver

Estrogen plays several distinct roles that matter for your joints and muscles:

1) Muscle repair and growth.

Estrogen supports the satellite cells responsible for repairing and building skeletal muscle. As estrogen declines, muscle protein synthesis becomes less efficient, contributing to the accelerated loss of muscle mass and strength seen after menopause (Critchlow et al., 2023; Hansen, 2018).

2) Inflammation control.

Estrogen has anti-inflammatory effects on muscle and connective tissue. Lower estrogen is associated with higher baseline inflammation, which can show up as generalized aches, tendon irritation, and slower recovery from exercise.

3) Bone density.

Estrogen slows the rate of bone breakdown. Its decline is the single biggest driver of the rapid bone loss that happens around the final menstrual period, which is why osteoporosis risk climbs so sharply in this window (Karlamangla et al., 2021).

4) Collagen and connective tissue.

Estrogen supports collagen production in tendons, ligaments, and cartilage. Research measuring tendon tissue directly has found that postmenopausal women on estrogen therapy have higher tendon collagen synthesis rates than those who aren't (Hansen, 2018), meaning their tendons are literally better equipped for ongoing repair. This is part of why frozen shoulder and tendon injuries become more common in this stage.

Progesterone: An Underexplored but Meaningful Role

Progesterone gets far less research attention than estrogen when it comes to musculoskeletal health, but it isn't inactive. It has a calming effect on the nervous system that influences sleep quality and pain perception, and both poor sleep and heightened pain sensitivity make other MSK symptoms feel worse. That alone makes progesterone relevant to how you feel day to day.

There's also emerging research on progesterone's more direct role in connective tissue. Progesterone receptors have been identified in tendon tissue, and some research suggests progesterone may support collagen synthesis rates in muscle in postmenopausal women (Hansen, 2018). At the same time, animal studies have shown progesterone can increase the expression of relaxin receptors in ligaments and tendons, which theoretically could make tissue more responsive to joint-loosening effects, though this evidence is largely limited to rodent models rather than human studies. Put simply, the current research suggests progesterone has a mixed, tissue-dependent effect, and the science is still catching up to what's seen clinically.

What is well established is that progesterone works alongside estrogen rather than independently, and has anti-inflammatory properties of its own. So as progesterone declines during perimenopause, you're losing more than estrogen's protective effects — you're also losing progesterone's contribution to sleep, pain modulation, and inflammation control.

Testosterone: Relevant Beyond Libido

Testosterone is routinely mislabeled as a "male hormone," but women produce it throughout their lives and actually have more testosterone than estrogen, with levels declining gradually with age, often starting well before menopause itself.

Its best-established, evidence-based clinical use in women remains the treatment of low sexual desire (Davis et al., 2019). But that's not the whole picture. A 2023 systematic review of observational studies examining endogenous testosterone levels found associations between testosterone concentrations and muscle mass, strength, and physical performance in women (Taylor et al., 2023) — an area of research that has historically been underexplored. Testosterone contributes to muscle protein synthesis and strength, plus it's a motivation hormone, motivation to get up and go, to move, all of which are directly relevant to musculoskeletal health.

"If training effort has stayed consistent but the results haven't, testosterone is worth discussing with your provider — not just in the context of libido, but in the context of strength and function."

What You Can Actually Do About It: Hormone Testing, Physiotherapy, and Strength Training in Calgary

The musculoskeletal syndrome of menopause is treatable, and a lot of it is preventable with early intervention. Managing it well usually comes down to two things working together: an accurate picture of your hormones, and a training approach suited to this new hormonal environment.

Start With a Hormone Consultation

A hormone consult can help put your symptoms and hormonal changes into context, including whether testing for estrogen, progesterone, and testosterone is appropriate for you. From there, your care team can use your symptoms, clinical history, and, when appropriate, lab results to guide treatment as you move through perimenopause and into postmenopause.

For women who are good candidates, current clinical guidance supports hormone therapy as a favourable option: for those under 60 or within 10 years of their final period, the benefit-risk balance generally favours symptom relief and bone protection (NAMS 2022 Hormone Therapy Position Statement Advisory Panel, 2022). However, if you are outside of that window, that doesn't necessarily mean you cannot safely take hormone therapy. This is where an individualized consultation is important, to help you understand your unique risk and benefit profile and determine whether hormone therapy is right for you.

Then Build a Body That Can Handle the Transition

Resistance training is one of the most effective tools available here. A 2024 systematic review and meta-analysis found consistent benefits of resistance training on strength, body composition, and physical function in healthy postmenopausal women (González-Gálvez et al., 2024). Strength training does what hormones alone can't:

Working with a physiotherapist, chiropractor, or strength coach who understands hormone-related musculoskeletal changes makes a real difference here. A generic program built for a 25-year-old's physiology isn't the right fit for a 48-year-old whose estrogen has dropped 40% in two years. Structured, joint-specific rehab — like shoulder, hip, or foot foundation programs — can be especially useful if you're already managing pain or an old injury and need to rebuild strength without aggravating it.

A Team Approach Works Best

Hormone health and musculoskeletal health aren't separate problems; they're the same problem viewed from two angles. That's the premise behind the partnership between Pause Health and Vital Performance Care: Pause Health handles the hormone side — testing, interpretation, and treatment where appropriate — while Vital Performance Care's physiotherapists, chiropractors, and strength coaches handle the movement side, building a program suited to what your body actually needs.

Conclusion

Joint pain, stiffness, muscle loss, and tendon injuries in your 40s and 50s are common. Common doesn't mean normal, and it doesn't mean untreatable. The musculoskeletal syndrome of menopause has a strong hormonal component, and understanding your estrogen, progesterone, and testosterone levels is often a key piece in explaining these changes. Paired with the right strength and rehab program, this is one of the more addressable parts of the menopause transition.

If you're in Calgary and dealing with new aches, stiffness, or strength loss that started around perimenopause, it's worth investigating rather than waiting. Get your hormones tested, get assessed, and build a plan suited to where your body actually is.

Book a Hormone Consult with Pause Health

Book a Clinical Musculoskeletal Assessment with a Chiropractor or Physiotherapist at Vital Performance Care

About the Author

Shelby Sheppard, BN, MN, FNP-C

Shelby Sheppard, BN, MN, FNP-C, is a Nurse Practitioner and the founder of Pause Health (pausehealth.ca), a virtual hormone and sexual health clinic based in Calgary, Alberta. Her practice focuses on hormone health, sexual medicine, and evidence-based menopause care.

Shelby is a community partner of Vital Performance Care, and the practitioners at Vital refer to and rely on Shelby to co-manage complex client cases with.

References

Critchlow, A. J., Hiam, D., Williams, R., Scott, D., & Lamon, S. (2023). The role of estrogen in female skeletal muscle aging: A systematic review. Maturitas, 178, 107844. https://doi.org/10.1016/j.maturitas.2023.107844

Davis, S. R., Baber, R., Panay, N., Bitzer, J., Cerdas Perez, S., Islam, R. M., Kaunitz, A. M., Kingsberg, S. A., Lambrinoudaki, I., Liu, J., Parish, S. J., Pinkerton, J., Rymer, J., Simon, J. A., Vignozzi, L., & Wierman, M. E. (2019). Global consensus position statement on the use of testosterone therapy for women. Climacteric: The Journal of the International Menopause Society, 22(5), 429–434. https://doi.org/10.1080/13697137.2019.1637079

González-Gálvez, N., Moreno-Torres, J. M., & Vaquero-Cristóbal, R. (2024). Resistance training effects on healthy postmenopausal women: A systematic review with meta-analysis. Climacteric: The Journal of the International Menopause Society, 27(3), 296–304. https://doi.org/10.1080/13697137.2024.2310521

Hansen, M. (2018). Female hormones: Do they influence muscle and tendon protein metabolism? The Proceedings of the Nutrition Society, 77(1), 32–41. https://doi.org/10.1017/S0029665117001951

Karlamangla, A. S., Shieh, A., & Greendale, G. A. (2021). Hormones and bone loss across the menopause transition. Vitamins and Hormones, 115, 401–417. https://doi.org/10.1016/bs.vh.2020.12.016

NAMS 2022 Hormone Therapy Position Statement Advisory Panel. (2022). The 2022 hormone therapy position statement of The North American Menopause Society. Menopause, 29(7), 767–794. https://doi.org/10.1097/GME.0000000000002028

Taylor, S., Islam, R. M., Bell, R. J., Hemachandra, C., & Davis, S. R. (2023). Endogenous testosterone concentrations and muscle mass, strength and performance in women, a systematic review of observational studies. Clinical Endocrinology, 98(4), 587–602. https://doi.org/10.1111/cen.14874

Tehalia, M. K., Agarwal, S., Lalwani, A., & Sharma, S. (2026). Estrogen deficiency in menopause: A major contributor to cartilage degeneration and osteoarthritis: A systematic review and meta-analysis. Journal of Menopausal Medicine, 32(1), 18–29. https://doi.org/10.6118/jmm.25141

Wright, V. J., Schwartzman, J. D., Itinoche, R., & Wittstein, J. (2024). The musculoskeletal syndrome of menopause. Climacteric, 27(5), 466–472. https://doi.org/10.1080/13697137.2024.2380363