In depth
MCTD / overlap and exercise
The nearest thing to a trial in this disease watched people exercise through a high corticosteroid course. Their fitness rose over the six weeks while their muscle fell away. Both of those happened in one set of people at once, and that's the finding worth having from it.
What the research found.
One group exercised through six weeks of high-dose corticosteroids for connective tissue disease. Their muscle mass fell 5.5 percent and their knee strength fell 9.7 to 11.6 percent. Two fitness measures rose all the same, one of them by 13.0 percent and the other by 9.0 percent.
Nagashima and colleagues, European Journal of Applied Physiology, 2021
A European reference network searched for care guidelines in mixed connective tissue disease. It found no guideline at all, so it read guidelines written for other connective tissue diseases, looking for parts that might apply here. That's what the field does here in place of a guideline of its own.
The 2017 American College of Rheumatology guideline covers every adult on a long corticosteroid course. It strongly advises four things, and those are getting calcium and vitamin D right, doing weight-bearing and strength-building exercise, stopping smoking, and cutting back on alcohol. That advice reaches a reader through their treatment rather than through their diagnosis.
What has been measured, and what hasn't
No trial of exercise in mixed connective tissue disease exists anywhere. One study comes close to it, and that study isn't in this disease alone, because it followed people with connective tissue disease more broadly. They were exercising through a high corticosteroid course at the time it was done.
The record this site holds adds a caution to that one study. How many of those people had this exact diagnosis couldn't be confirmed, so what this page gives you is borrowed rather than direct. That's worth knowing before you weigh any of it up.
There's a second reason to be careful with all of this. This disease overlaps lupus, systemic sclerosis, and myositis without being any one of them, so a finding in a mixed group of connective tissue disease patients may or may not describe you. The work that would settle the question has never been done.
Describing your weakness accurately
Where your weakness sits changes what a plan ought to be built around. Weakness at the hips and shoulders shows itself in specific ways, and getting out of a chair without pushing off with your arms gets hard. Stairs get hard, and lifting something overhead gets hard along with them.
That's a different problem from weakness in the hands, and different again from being generally tired. So mention which one of the three you mean when somebody asks you about it. Somebody who says they feel tired gets different advice from somebody who can't get out of a low chair without help.
It's worth separating breathlessness from weakness as well. New shortness of breath belongs in an appointment rather than in a training plan, every time. Lung trouble, including high pressure in the lung vessels, is known across the diseases this one overlaps with.
Exercising through a corticosteroid course
One study has anything like a treatment in it, and it followed people exercising through a high-dose corticosteroid course for connective tissue disease. Over six weeks their muscle mass fell 5.5 percent, and their knee strength fell 9.7 percent on the left and 11.6 percent on the right. Two fitness measures rose over that stretch, one by 13.0 percent and the other by 9.0 percent.
Read that carefully, because the split is the point. It says exercise did better at guarding fitness than at guarding muscle at high corticosteroid doses, with both fitness measures rising while both muscle measures fell. One set of people, over one stretch of six weeks.
That's worth knowing before you start a program expecting to hold your strength through treatment. It doesn't argue against exercising at all, and it argues against being let down when the strength numbers don't cooperate. The record here adds that the group had connective tissue disease of various kinds, so what you're reading is borrowed rather than direct.
Why there's no program to give you
A European reference network searched for care guidelines in mixed connective tissue disease and found no guideline. So it read guidelines written for other connective tissue diseases, looking for parts that might apply here. It also set out three jobs for future guidelines, which are how to make the diagnosis, what to check over time, and treatment.
So the advice you get comes from documents written for lupus, systemic sclerosis, myositis, or rheumatoid arthritis. A doctor applies them using judgment, which is fair practice in a rare disease with no guideline of its own to use. What's worth knowing is that this is what's happening, and no protocol exists.
This disease overlaps those others without being any of them, which is why the transfer isn't automatic. Take two examples of it, both of them real. Advice on watching the lungs, written for systemic sclerosis, and advice on watching the kidneys, written for lupus, may both fit you or neither may, and that's a judgment call each time.
What does apply, and what should stop you
Most people with this diagnosis take corticosteroids at some point, and that brings the one concrete rule there is. The 2017 American College of Rheumatology guideline covers every adult on a long course. It strongly advises getting calcium and vitamin D right, doing weight-bearing and strength-building exercise, stopping smoking, and cutting back on alcohol.
Weight-bearing and strength-building are the useful words in all of that. They're especially useful given what the corticosteroid study found about muscle over its six weeks. A high-dose course is a time for more strength work rather than less of it, on that evidence.
New shortness of breath needs a look rather than being written off as being unfit. Lung trouble, including high pressure in the lung vessels, is known across the diseases this one overlaps. Cold-triggered finger attacks are worth mentioning too, and so is any sore on a fingertip, because blood vessel trouble is part of this illness and those sores heal badly.
Common misconceptions.
Myth. Reduced exercise capacity must mean my heart or lungs are affected.
Reality. It might mean that, and it might not. Muscle weakness produces the identical feeling, and a corticosteroid course is one thing that causes it. No study held here is strong enough to tell you which of the two is commoner, so the answer is to get it checked rather than assumed, and new shortness of breath in particular belongs in an appointment.
Myth. Exercise will hold on to my muscle through a steroid course.
Reality. One group exercised right through a high corticosteroid course. Their muscle mass still fell 5.5 percent over six weeks, and their knee strength still fell about 10 percent. Their fitness measures rose over that stretch, by 13.0 and 9.0 percent, so it looks like exercise guards fitness better than it guards muscle at high doses.
Myth. There's a program designed for this disease.
Reality. No exercise trial in this disease exists, and no care guideline for it exists either. A European reference network went looking for guidelines and found no guideline, so it read documents written for other connective tissue diseases and looked for parts that might apply. Anything specific you're given is coming from one of those documents.
Myth. Advice for lupus or systemic sclerosis transfers cleanly.
Reality. It's what gets used, because there's nothing else available. The reference network was plain about that, and borrowing is what the field does, which is a different thing from saying the borrowing has been checked. This disease overlaps lupus, systemic sclerosis, and myositis without being any of them, so a guideline written for one of those needs a doctor's judgment before it fits you.
Cautions specific to this condition.
- Get new shortness of breath looked at, because being out of condition is the easy explanation and not always the right one. Lung trouble, including high pressure in the lung vessels, is known across the diseases this one overlaps.
- Mention any cold-triggered finger attack, and any sore on a fingertip. Blood vessel trouble is part of this illness, and those sores heal badly.
- The 2017 corticosteroid guideline asks for weight-bearing and strength work in anyone on a long course. Those are its own words. Your team can say whether it fits you.
- Say where your weakness really sits. Tell whoever supervises you whether it's stairs and getting up from a chair, or your hands, or general tiredness. Those need different plans.
- Muscle mass fell even in the people who exercised right through a corticosteroid course. So a long course isn't a time when strength work stops counting.
- Work with somebody who knows no guideline exists for this disease. Then your plan gets built from what you can do.
Discuss any change with the rheumatologist who manages your care. Nothing here replaces that conversation.
Questions patients ask.
What's known about exercise in this disease?
Very little is known, and not one piece of it is a trial in this disease. The nearest thing followed people with connective tissue disease of various kinds exercising through a high corticosteroid course. The record here can't confirm how many of them had this exact diagnosis, so what you get is borrowed rather than direct, and this page says so rather than hiding it.
Why is my exercise capacity low?
There are several possible reasons and no study in this disease strong enough to rank them. Muscle weakness is one of them, and a corticosteroid course is one cause of that. Lung trouble is another, and it's known across the diseases this one overlaps, so it's worth having looked at properly and early.
Does exercise help during steroid treatment?
One study followed people exercising through a high corticosteroid course for connective tissue disease. Over six weeks their muscle mass fell 5.5 percent and their knee strength fell 9.7 to 11.6 percent, while two fitness measures rose, by 13.0 percent and 9.0 percent. The record here adds a caution, because how many of those people had this exact diagnosis couldn't be confirmed.
What does that tell me about a steroid course?
That exercise seems to guard your fitness better than your muscle at high corticosteroid doses. Both fitness measures rose while both muscle measures fell, in one set of people over one stretch of six weeks. So know that before you start a program expecting to hold your strength through treatment, because it's an argument against being let down rather than against exercising.
Is there a guideline for this condition?
No, and a European reference network searched for care guidelines in this disease and found no guideline. So it read guidelines written for other connective tissue diseases, looking for parts that might apply here. It also set out three jobs for future guidelines, which are how to make the diagnosis, what to check at the start and over time, and treatment.
What applies to me, then?
The corticosteroid guideline applies, if you're on a long course, and most people with this diagnosis are at some point. It's the 2017 American College of Rheumatology guideline. It strongly advises getting calcium and vitamin D right, doing weight-bearing and strength-building exercise, stopping smoking, and cutting back on alcohol.
How should I start?
Start from what you can do now, with somebody who knows no protocol for this disease exists. Tell them where your weakness sits, because that changes which movements a plan gets built from. Expect a plan built for you alone, because the reference network said as much, and a plan built for one person is what the field has.
References.
- Nagashima M; Takahashi D; Mizushima T et al. Effects of exercise in patients with connective tissue disease receiving high-dose glucocorticoids: a pilot prospective cohort study. Eur J Appl Physiol. 2021;121:2253-2263. 10.1007/s00421-021-04697-2Pilot prospective cohort study
- Chaigne B; Scirè C; Talarico R et al. Mixed connective tissue disease: state of the art on clinical practice guidelines. RMD Open. 2018;4:e000783. 10.1136/rmdopen-2018-000783Systematic literature review for clinical practice guidelines
- van der Net J; Wissink B; van Royen A et al. Aerobic capacity and muscle strength in juvenile-onset mixed connective tissue disease (MCTD). Scand J Rheumatol. 2010;39:387-392. 10.3109/03009741003742714Cross-sectional observational study of aerobic capacity and muscle strength in juvenile-onset MCTD
- Buckley L; Guyatt G; Fink H et al. 2017 American College of Rheumatology Guideline for the Prevention and Treatment of Glucocorticoid‐Induced Osteoporosis. Arthritis & Rheumatology. 2017;69:1521-1537. 10.1002/art.40137GRADE-based clinical practice guideline
This page gathers the published research on this subject into one place. The studies behind it were published between 1989 and 2026, and every figure links to the paper it came from. Those studies were peer reviewed. This summary of them was not. Dr. Sarah Luebker is reviewing these pages one at a time and has not reached this one yet, so it carries no medical review date and nothing here is her opinion or her advice to you. Each page gets updated as she reaches it. It is here in the meantime because the science is worth having in one organized place that is easy to find and easy to read. Talk to your own clinician before acting on any of it.