Effectiveness of Exercise in Management of Fibromyalgia

Curr Opin Rheumatol 16(2):138-142, 2004.

Susan E. Gowans [a,c] and Amy deHueck [b]

[a] Department of Rehabilitation Services, University Health Network,
[b] Physiotherapy Department, Joseph Brant Memorial Hospital, and
[c] Department of Physical Therapy, University of Toronto, Toronto, Ontario,
Canada

Correspondence to Susan E. Gowans, Department of Rehabilitation Services, gw
1-553, University Health Network, Toronto General Hospital, 200 Elizabeth
Street, Toronto, Ontario, Canada. Tel: 416 340 4800, ext. 4408; fax: 416 977
1467; e-mail: mailto:sue.gowans@uhn.on.ca


Abstract
Purpose of Review: Exercise was established as an integral part of the
nonpharmacological treatment of fibromyalgia approximately 20 years ago. Since
then many studies have investigated the effects of exercise-either alone or in
combination with other interventions. This review will discuss the benefits of
exercise alone and provide practical suggestions on how patients can exercise
without causing a long-term exacerbation of their pain.
Recent Findings: Short-term exercise programs for individuals with fibromyalgia
have consistently improved physical function, especially physical fitness, and
reduced tenderpoint pain. Exercise has also produced improvements in
self-efficacy. These effects can persist for periods of up to 2 years but may
require participants to continue to exercise. Most exercise studies have
examined the effects of moderately intense aerobic exercise. Only in the past 2
years have muscle-strengthening programs, in isolation, been evaluated. To be
well tolerated, exercise programs must start at a level just below the capacity
of the participants and then progress slowly. Even with these precautions,
exercise may still produce tolerable, short-term increases in pain and fatigue
that should abate within the first few weeks of exercising.
Summary: Future studies should investigate the possible benefits of
low-intensity exercise and test strategies that may enhance long-term
compliance with exercise. Individuals with fibromyalgia also need to be able to
access community exercise programs that are appropriate for them. This may
require community instructors to receive instruction on exercise prescription
and progression for individuals with fibromyalgia.

Introduction
Fibromyalgia is a condition characterized by widespread pain and pain at
specific tender points.[1] Typically, individuals with fibromyalgia are also
inactive and unfit.[2,3] Exercise was established as an integral part of the
nonpharmacological treatment for individuals with fibromyalgia less than 20
years ago by the demonstration that patients randomized to 20 weeks of
high-intensity exercise had greater improvements in fitness, tender point pain
thresholds, and patient/physician global assessment ratings than patients
randomized to 20 weeks of flexibility training.[4] Since then, an escalating
number of randomized controlled trials have evaluated the benefits of exercise
for individuals with fibromyalgia. Subsequent exercise trials have, by and
large, examined the benefit of moderately intense aerobic exercise, either
alone, or in combination with other interventions, such as muscle strengthening
or education. Only in the past 2 years have a limited number of studies
examined the effect of muscle strengthening, in isolation, for individuals with
fibromyalgia. Four meta-analyses have also examined the benefits of exercise
for individuals with fibromyalgia: 3 meta-analyses examined the effects of
exercise in reviews with other nonpharmacological interventions[5-7*] and a
recent, fourth meta-analysis focused solely on the effects of exercise.[8**]
This fourth meta-analysis limited its study to exercise interventions that met
or exceeded established criteria for improving aerobic conditioning or
strengthening.

This review summarizes the literature on exercise for individuals with
fibromyalgia and highlights relevant exercise studies that have been published
between January 2002 and September 2003.


Effect of Exercise on Physical Function
Physical function is a common outcome for exercise studies in fibromyalgia.
Physical function has been evaluated in terms of cardiovascular fitness,
self-reported physical function, or musculoskeletal performance (eg, muscle
strength or a functional task like the sit and reach test).

Moderately intense aerobic exercise has consistently improved physical
function, particularly cardiovascular fitness, in individuals with
fibromyalgia.[8**] Because individuals with fibromyalgia are often
deconditioned and unfit, it is not surprising that aerobic exercise would
improve their cardiovascular fitness. However, these gains are important since
the pain associated with fibromyalgia can lead to decreased activity and
deconditioning, and then deconditioned muscles make even lighter activities
painful, which further reduces activity.

Aerobic exercise has less consistently improved musculoskeletal function (eg,
muscle strength or endurance)[8**] but this may be because aerobic exercise
interventions do not meet the criteria for improving muscle strength (eg, 8-12
repetitions of an individual exercise performed 2+ times/wk, and progressed
over time). Muscle strength has improved in all three studies that evaluated
the effects of a specific muscle-strengthening program.[9*-11*] However, these
improvements in strength were significantly different from control subjects in
only one[10] of the two randomized controlled trials.[10,11*] Participants'
self-reported physical function (typically the activities of daily living) has
less consistently been improved by exercise.[8**]

Effect of Exercise on Pain
Pain is another common outcome for exercise studies in fibromyalgia. Pain has
been measured as the number of tender points, the thresholds for tender points
(eg, a cumulative myalgia score), and/or participants' self-reported level of
pain (eg, visual analogue scales, pain diagrams, questionnaires).

Although short-term aerobic exercise programs have not, with few exceptions
decreased the number of tender points,[12-14] exercise has increased the
thresholds for tender point pain in both primary exercise trials and in
meta-analyses.[8**] These increases in tenderpoint thresholds may mean that
exercise can decrease central pain perception, which is believed to be
increased in fibromyalgia.[15]

The effect of aerobic exercise on self-reported pain has been tested more
frequently with mixed results. Self-reported pain has decreased in only about
half of the existing, high-quality studies and this effect is not significant
in meta-analysis.[8**] Although exercise may or may not decrease self-reported
pain, it is important to note that by the end of short-term exercise programs,
pain has not increased. Clinically, individuals with fibromyalgia often shun
exercise because they believe it will increase their pain but exercise that is
started at a level that is suitable to participants' fitness levels and
progressed slowly should produce only tolerable and transient increases in pain
that abate after the first few weeks of exercise.

Effect of Exercise on Self Efficacy
Self efficacy is the perception of an individual that he/she can perform a
specific behavior or complete specific task(s).[16] Self efficacy emerged as an
important outcome measure in rheumatology with the demonstration that arthritis
self-management programs improved participants' self efficacy and the fact that
these improvements in self efficacy were related to changes in participants'
health status.[17] Self efficacy, particularly self efficacy for function, has
also been improved by aerobic exercise in individuals with fibromyalgia.[18-21]
These changes in self efficacy are noteworthy since higher levels of self
efficacy for function and pain have been associated with improvements in
physical function and mood[20] and lower levels of pain and physical
impairment.[22]

Effect of Exercise on Fatigue/Sleep
Individuals with fibromyalgia frequently report poor sleep quality and
subsequent fatigue.[1] Many individuals with fibromyalgia also have objective
evidence of an arousal disturbance on electroencelographic recording during
sleep.[23] While exercise is able to improve the sleep of healthy, older
adults,[24] few exercise programs for individuals with fibromyalgia have had
significant effects on self-reported fatigue or sleep quality.[8**]

Effect of Exercise on Mood
Anxiety and depression are frequently reported by individuals with
fibromyalgia.[1] In healthy individuals and individuals with psychiatric
disease, exercise is known to improve depression[25] and anxiety.[26] The
effect of exercise on anxiety and depression of individuals with fibromyalgia
has received less scrutiny than pain or function but, when assessed, the
results have, with few exceptions,[10,20,27] been negative[8**]; that is,
anxiety and depression did not improve in exercise participants when compared
with control subjects.

Types of Exercise
Aerobic. A variety of aerobic activities (walking, cycling, dancing, water
exercises) have been shown to be beneficial for individuals with fibromyalgia
but only one study has compared the benefits of one type of aerobic exercise to
another type. This study found that both exercise in a warm pool (water
temperature: 93°F) and land-based walking improved cardiovascular fitness, but
only pool exercises produced significant improvements, compared with baseline
values, in self-reported pain, anxiety, and depression.[13] However, these
differences were small in absolute size, and insufficient from a scientific or
clinical perspective, to commend pool programs (which are hard to find in the
community) over walking programs (which are easy for individuals to initiate by
themselves). But, practically, there is a subset of fibromyalgia patients who
have may be particularly suited to pool programs as an initial means of
exercise: namely those who have significant complaints of musculoskeletal pain
or those who fear that exercise will exacerbate their pain. The buoyancy of the
water will limit the impact of exercise on weight-bearing joints and
potentially limit exercise-induced pain. Also, warm, therapeutic pools, where
the water temperature is 93°F or greater, have the added benefit of providing
immediate treatment for any exercise-induced pain. Furthermore, although warm
pools are hard to find in the community, even pools, with a water temperature
of 85°F or more, will be better tolerated by individuals with fibromyalgia (who
may be more sensitive to cold) than standard community pool programs, where the
water temperature is lower.

Anaerobic (strengthening). Several exercise studies have combined strengthening
with aerobic exercise but only recently have three studies tested the benefits
of strengthening in isolation.[9*,10,11*] To limit exercise-induced pain, it
has been suggested that strengthening programs: (1) minimize eccentric
exercises (ie, activities where the muscle is actively contracting while it is
being passively lengthened (eg, contraction of elbow flexors to slow the
descent of a heavy object to a table); (2) include pauses between exercise
repetitions; (3) perform exercises for upper extremity muscle groups and lower
extremity muscle groups in separate sessions, with at least 1 day of rest
between sessions.[28] It has also been suggested that eccentric muscle work
(eg, arms overhead) be avoided in other exercise programs.[28] However, we have
found that even individuals who are significantly deconditioned can tolerate
arm movements above their shoulders during land or pool aerobic programs if
they are introduced gradually.[20]

Flexibility. Stretching is an integral part of warm-up and cool-down exercises
but there is no theoretical basis for stretching to be beneficial in isolation.
Empirically, stretching did produce some benefits in the two exercise studies
in which it was used as the control condition, but more improvements were seen
in the intervention groups in both trials.[4,11*] To avoid subsequent
exercise-induced pain, stretching should stop at the point of slight resistance
and not produce pain.[28] In the subgroup of individuals with fibromyalgia and
joint hypermobility,[29,30] greater care must be taken to avoid overstretching
during flexibility exercises. But exercise per se is not contraindicated for
individuals with joint hypermobility. In fact, individuals with fibromyalgia
and hypermobility may show greater improvements with exercise than other
individuals with fibromyalgia.[29]

Exercise Intensity
The first study that examined the benefits of exercise in fibromyalgia did so
by comparing high-intensity exercise (heart rate of 150 beats/min for 20 to 30
minutes) to flexibility training.[4] However, high-intensity exercise is
unsuitable for most individuals with fibromyalgia who are deconditioned and
unfit[2,3] and subsequently, most studies have examined the benefits of
moderately intense exercise (55 to 75% of age-adjusted maximal heart rate [220
minus age]). In individuals who are deconditioned and unfit, moderate intensity
can be achieved with very low levels of exercise. A recent, well-designed study
also demonstrated that low-intensity exercise (self-determined) can produce
improvements, in multiple domains, for individuals with fibromyalgia.[27] This
latter study suggests that even low-intensity exercise may be beneficial for
individuals with fibromyalgia.

To date, only one study has directly compared the benefits of exercise that
vary in intensity. This study examined the benefits of 20 weeks of
low-intensity exercise (self determined) versus what the authors termed
high-intensity exercise (70% of maximal heart rate, corrected for age). In this
small study, only high-intensity exercise was able to produce improvements in
fitness and well being but these improvements were achieved at a cost since
self-reported pain also increased for individuals enrolled in the
high-intensity exercise program.[31*]

While definitive dose response studies of exercise intensity are still lacking,
from a practical perspective, exercise programs should start at levels just
below the capacity of participants and gradually increase the duration and
intensity until participants are exercising at the low end of moderate
intensity for 20 to 30 minutes. Furthermore, even with these precautions,
participants must be aware that they may have some, tolerable short-term
increases in pain and fatigue but, if they exercise at an appropriate
intensity, these symptoms should return to baseline levels within the first few
weeks of exercise. Also, patients may be able to do more, with the same or less
pain, after only a few weeks of exercising. These practical principles for
exercise prescription are explored in more depth in several recent
papers[28,32*,33*] and in a pending treatment guideline for fibromyalgia by the
American Pain Society that is expected to be released in 2004.

Studies that examine the benefits of exercise that vary in duration are also
lacking; however, one recent study examined whether there was any benefit in
performing aerobic exercise in two 15-minute bouts of home-based aerobic
exercise, 3 to 5 times per week versus one 30-minute home-based exercise
session with similar weekly frequency. This study found no additional benefits
in fractionating exercise into smaller bouts in terms of compliance or
attrition, although their definition of compliance was high (92% compliance
with 3 sessions per week over a 4-week period).[34*]

Exercise Setting
Most of the published exercise studies in fibromyalgia studies were conducted
in specialized hospital settings. However, several recent studies have had
subjects exercised independently in their own homes using standardized exercise
videotapes[34*] or in groups at community-based healthy living centers[35*] or
YWCAs.[14] These papers are noteworthy since home and community settings have
greater generalizability to the large numbers of people with fibromyalgia who
seek treatment outside of a specialized setting.

Long-Term Benefits of Exercise
While the number of exercise studies has substantially increased in the past 10
years, fewer studies have examined the benefits of exercise beyond the exercise
program; also, the follow-up periods for these studies, at 3 months[36] to 4
years,[37] have been relatively short.

Follow-up studies have, typically, measured the same types of outcomes
(physical function, pain, self-efficacy, mood, and fatigue) that have been used
to track the immediate benefits of exercise. Generally, follow-up studies have
found that gains were maintained in outcomes that showed the most consistent,
immediate benefit from exercise. Thus, gains have been maintained in physical
function (especially cardiovascular function[13,20,21,27,36*]), pain
(especially tender point thresholds[18,21]), and self efficacy (especially self
efficacy for pain[18-20]) for follow-up periods that varied, but could be as
long as 2 years. Fatigue and mood, outcomes less likely to be improved by
short-term exercise, are also less likely to be improved at follow-up (but
see[20,38]).

Exercise compliance at follow-up has also not been consistently tracked and
compliance at follow-up has varied, partly because of different definitions of
exercise adherence. For example, some studies have judged that individuals are
adherent if they exercised once a week,[13] while other studies required
individuals to exercise 30 minutes, 4 times a week to be deemed adherent.[37]
However, compliance (however defined) can be as high as 50% or more, 3 to 6
months[13,19,39] or 2 years following a supervised exercise program.[38]

Furthermore, to obtain long-term benefits from exercise, participants may need
to continue to exercise as all three studies that have evaluated this have
found a positive relation between ongoing exercise compliance (however defined)
and the maintenance of exercise-induced changes in fibromyalgia. In the first
study, 4 years following the end of a supervised exercise program, the four
individuals who continued to exercise (30 minutes or more, 4 times/wk) had
significant improvements on 6 of 8 outcomes, compared with the 11 individuals
who had stopped exercising.[37] In the second study, there was a positive
relationship between individuals who exercised at 3- to 6-month follow-up (30
or more min/wk) and the maintenance (yes/no) of gains in 6-minute walk
distance.[39] In the third study, there was a positive correlation between
minutes of aerobic exercise at 1-year follow-up and gains in 6-minute walk
distance at follow-up [Gowans, deHueck, Voss et al., unpublished data].

Conclusion
Moderately intense aerobic exercise is beneficial for people with fibromyalgia,
particularly for improving their physical fitness and self efficacy, and
reducing their tender point pain. Further studies need to address whether the
benefits from low-intensity aerobic exercise, demonstrated in one well-run
study, can be replicated. Muscle strengthening, in isolation, has only recently
been tested for individuals with fibromyalgia and the benefits, suggested by
these studies, need to be replicated by other controlled studies. Subsequent
studies of strengthening should also continue to test whether strengthening, in
isolation, can improve outcomes besides physical function. Follow-up studies
suggest that long-term compliance with aerobic exercise will produce an ongoing
benefit for physical function, pain reduction, and self efficacy. Since
long-term compliance with exercise is difficult to achieve, further studies
need to test strategies to enhance long-term exercise compliance for
individuals with fibromyalgia. Finally, if exercise is to become a strong
component of community care for individuals with fibromyalgia, individuals must
be able to access community-based exercise programs that are sensitive to their
needs; specifically, exercise programs that begin slowly and progress slowly.
This may require specific training for community instructors regarding exercise
intensity and progression although one study successfully evaluated exercise
programs at community-based healthy living centers that were run by personal
trainers with no previous experience with clinical populations.[35*]


References:
Papers of particular interest, published within the annual period of review,
have been highlighted as:

* Of special interest
** Of outstanding interest

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