Wadell (2004) High intensity physical group training in water–an effective training modality for patients with COPD.

High intensity physical group training in waterFan
effective training modality for patients with COPD
Karin Wadella,c,*, Gunnevi Sundelina, Karin Henriksson-Lars!
enb,
Rune Lundgrenc
aDepartment of Community Medicine and Rehabilitation, Physiotherapy, Ume(
a University, SwedenbDepartment of Surgical and Perioperative Sciences, Sports Medicine, Ume(
a University, SwedencDepartment of Respiratory Medicine and Allergy, University hospital, Ume(
a, Sweden
Received 21 July 2003; accepted 24 November 2003
SummaryThe aim of this study was to examine the effect of high intensity physical
group training in water and on land for patients with COPD with regard to physical
capacity and health related quality of life (HRQoL). A controlled, semi-randomised
study was conducted where 30 patients were randomised to training either in water
or on land. Thirteen patients constituted a control group. Forty-three outpatients,
with moderate to severe COPD (27 w16 m), from two local hospitals in northern
Sweden, were included in the study. High intensity physical group training in water
(water group) or on land (land group) was performed for 12 weeks, three times per
week, 45 min per session. The control group received no intervention. Pre- and post-
intervention, all patients performed incremental and endurance shuttle walking
tests (ISWT and ESWT), cycle ergometer tests and responded questionnaires about
HRQoL (St. Georges Respiratory QuestionnaireFSGRQ and SF-36). The patients
trained with a mean heart rate of 8090% of peak heart rate. Both training groups
increased the distance walked, i.e. land group in ISWT (25 m) and water group in
ESWT (179 m). The water group increased the distance in ESWT signicantly more
that both the land and the control groups. Both training groups increased the time
cycled (4085 s) and work load (1020 W) in the cycle ergometer test. The control
group deteriorated in HRQoL according to total score in SGRQ while the training
groups remained constant. The water group improved their activity score in SGRQ
and their physical health score in SF-36 and those improvements were signicant as
compared to the land and the control groups. In conclusion, high intensity physical
group training in water is of benet for patients with COPD. It was in some areas
found to be even more effective regarding improvements in physical capacity and
experienced physical health compared to the same kind of training on land.
&2003 Elsevier Ltd. All rights reserved.
Introduction
Patients with chronic obstructive pulmonary dis-
ease (COPD) often complain of disabling breath-
lessness and reduced exercise capacity.
1Despiteoptimal medical treatment patients often experi-
ence a functional decit associated with dyspnea
and deconditioning as well as decreased health
related quality of life.
2
There is currently compelling evidence that
exercise training induces considerable physiological
effects and improves measures of exercise toler-
ance. As such, exercise training represents a
ARTICLE IN PRESS
KEYWORDS
COPD;
Physical group training;
Water exercise;
Physical capacity;
Health related quality of
life
*Corresponding author.
E-mail address:karin.wadell@physiother.umu.se (K. Wadell).
0954-6111$ - see front matter&2003 Elsevier Ltd. All rights reserved.
doi:10.1016j.rmed.2003.11.010 Respiratory Medicine (2004)98, 428438

cornerstone of the interdisciplinary management of
COPD patients as it has been shown to improve the
patients exercise tolerance and symptoms of
dyspnea.
1Also, pulmonary rehabilitation including
exercise training has in many studies been shown to
improve the patients health related quality of
life.
35
Different training modalities have been evalu-
ated to uncover the most effective way of training
patients with COPD. More than a decade ago,
Casaburi et al.
6showed that training at high
intensity (80% of baseline peak work-rate) was
superior to low intensity training (50%) regarding
physiologic training responses. In a recent study
interval training was found to be as effective as
continuous training.
7Also recently resistance train-
ing was shown to have similar effects on peripheral
muscle force, exercise capacity and health-related
quality of life as did endurance training.
8Ortega
et al.9concluded that combined strength and
endurance training is more effective than each of
these training programmes alone. Exercise training
as a component to outpatient pulmonary rehabili-
tation programmes, has been shown to be cost
effective and is likely to result in nancial benets
to the health service.
10,11
Even though much research has been done on
different training methods, there is still a need for
evaluating new training modalities for this increas-
ing group of patients. Since the number of COPD
patients increases it is also important to nd
methods that are cost effective. In most previous
exercise studies the patients have performed the
endurance training individually on either a tread-
mill or on a cycle ergometer.
7,8The strength
training has also been performed individually with
weights, expanders or in different apparatus.
8,9
Group training in a gymnasium has been used for a
long time in health promotion and has been found
to be effective in patients with asthma,
12cardiac13
and different musculoskeletal14,15disorders,
though it has not yet been evaluated in patients
with COPD. Besides the psychological and psycho-
social benets of getting patients together in a
group, specic equipment is not required, and up
to twenty patients can train under supervision from
one leader. Another aspect is that this kind of
training is available in the society and can be
adjusted to t patients with specic needs.
Water exercise is another form of training that
has been used for decades in the areas of
physiotherapy, physical medicine, and rehabilita-
tion. The buoyancy of the water is of relevance for
individuals seeking ways to improve tness without
the inherent risk of musculoskeletal injuries ac-
crued with continuous impact on the skeletalsystem.
16Training in water was shown to be
effective in healthy persons (young and el-
derly)
16,17and in different patients groups such as
asthmatics,12patients with poliomyelitis,18bro-
myalgia syndrome19and rheumatoid arthritis.20
Perk et al.21concluded that training in water was
applicable and safe in patients with COPD. It may
be an attractive alternative as it combines ele-
ments of strength, endurance and mobility training
as well as psychosocial and low-cost benets of
group training. To our knowledge no studies have
evaluated the effect on physical capacity and
quality of life after a period of aerobic group
training in water or on land among patients with
COPD.
The aim of this study on COPD patients was
therefore to compare the effect of high intensity
physical group training in water and high intensity
physical group training on land to a non-training
control group with regard to physical capacity and
to health related quality of life.
Materials and methods
Patients
Forty-three patients (27 women and 16 men) with
stable, moderate to severe COPD, according to
GOLD criteria,
22were included in the study. The
subjects were recruited from previously diagnosed
outpatients, under treatment at two hospitals in
Northern Sweden. The inclusion criteria were
FEV
1o80% of predicted, FEV1VCo70%, stable
medication and no infection during the last month
before entering the study. Patients with cardiac,
orthopaedic, neurological, or psychological disor-
ders that might have interfered with exercise
performance were excluded. Before entering the
study all patients performed a spirometry test
(Spirolab, Medical International Research, Roma,
Italy) and an exercise electrocardiogram test on a
cycle ergometer (Rodby
TM, RE 829, Enh.
orna,
Sweden). All patients gave their informed consent
prior to the study and the Ethics Committee of
Ume(
a University, Sweden, approved the study. Base
line characteristics of the patients are shown in
Table 1.
The climate, pollution and environmental factors
were the same in the areas from where the patients
were recruited. All patients were offered pneumo-
coccal and inuenza vaccination in order to avoid
drop-outs during the study since the intervention
proceeded during the inuenza season.
ARTICLE IN PRESS
High intensity physical group training in waterFan effective training modality for patients with COPD429

Study protocol
The study design was controlled and semi-rando-
mised. Thirty patients, living within 60 km from the
hospital where the study took place, were rando-
mised to physical group training either in water
(water group) or on land (land group). At randomi-
sation the patients were stratied according to sex,
FEV
1and working capacity. Patients living 60
130 km from the study hospital (13 patients) were
included in the control group.
Outcome measurements
Before and after the intervention period the
patients completed a set of tests.
Walking tests: The Incremental Shuttle Walking
Test (ISWT)
23and the Endurance Shuttle Walking
Test (ESWT)24were used. Before and after the
walking tests the patients rated their dyspnea and
leg fatigue according to Borg (CR10, category ratio
scale).
25Heart rate and oxygen saturation (SpO2)
were measured at rest and directly after tests with
a pulse oximeter (Omeda Biox 3700e, Louisville, KY,
USA). Instructions during the tests were standar-
dised and no encouragement was given.
Cycle ergometer test: An incremental symptom-
limited test on cycle ergometer (Rodby
TM, RE 829,
Enh.
orna, Sweden) with ECG-registration was per-
formed with the measurement of lactate from a
venous cannula in the arm. A ramp protocol was
used, i.e. all patients started at 20 W and the load
was increased by 20 W every third minute until
exhaustion. The patients SpO
2and Borg ratings for
dyspnea (CR10) and for rated perceived exertion
(RPE)
25were monitored at the end of every load.
During the maximal test the patients oxygen
uptake (VO
2), carbon dioxide production (VCO2)and ventilation (VE) were measured with a meta-
bolic stress test system (MetaMax II, Cortex,
Biophysik GmbH, Leipzig, Germany). Instructions
during the tests were standardised and no encour-
agement was given.
Questionnaire: Health related quality of life
(HRQoL) was evaluated with the disease specic
St. Georges Respiratory Questionnaire (SGRQ)
26and
the generic Short Form 36 (SF-36).27The results in
SF-36 were compared with normal values for a
healthy Swedish population over 65 years of age.
28
Once a month, during the study period, all patients
answered an activity level questionnaire29and
some questions about health status and the use of
medical care. The intervention in the study was not
to be taken into account when answering the
activity level questionnaire.
Spirometry: FEV
1, VC and FVC were measured
with a spirometer (Spirolab, Medical International
Research, Roma, Italy).
Intervention
The intervention was physical group training either
in water (water group) or on land (land group)
according to randomisation. The training pro-
gramme for both intervention groups consisted of
outpatient aerobic group training for 45 min (in-
cluding warm-up and cool-down) three times per
week for 12 weeks. Physiotherapists led the
training. The programmes in water and on land
were designed to have the same intensity prole,
presented inFig. 1. The sessions started with
warm-up and exibility exercises for 9 min. The
session was then performed in the following order:
4 min endurance exercises, 3 min strength exercises
for the legs, 4 min endurance exercises, 3 min
strength exercises for the arms, 4 min endurance
ARTICLE IN PRESS
Table 1Characteristics of the patients included in the study.
Control (n13) Water (n15) Land (n15)P-value
Sex (fm) 67 114 105
Age 63 (7) 65 (4) 65 (7) ns
Height (m) 1.70 (0.10) 1.64 (0.07) 1.63 (0.07) ns
Weight (kg) 75 (12) 80 (15) 70 (11) ns
FEV
1(l) 1.34 (0.40) 1.31 (0.31) 1.26 (0.34) ns
FEV
1% pred. 49 (12) 56 (11) 53 (12) ns
FVC (l) 3.18 (0.74) 2.73 (0.76) 2.78 (0.77) ns
FVC % pred. 93 (14) 94 (17) 96 (21) ns
FEV % 41 (15) 46 (8) 42 (10) ns
Work rate
peak(W) 85 (31) 76 (26) 71 (31) ns
KruskalWallis was used for comparison between groups.
Values presented as mean (SD).
430K. Wadell et al.

exercises, 3 min strength exercises for the torso,
3 min exibility exercises and nally cool-down and
stretching exercises for 12 min. The intensity
increased for each successive endurance exercise
portion. The endurance parts of the session con-
sisted of varied repetitive large-muscle exercises
intending to increase the load on the cardiovascular
system and increase heart rate. The complete
programme was supported by music, which guided
the intensity of the performance during the session.
The water temperature was 33341C. The land
training was performed in a gymnasium.
The intensity during the training sessions was
monitored using heart rate registration (Polar
Accurex Plus
TM, Polar Elektro Oy, Kempele, Finland)
once weekly and the patients rated their dyspnea
(CR10) and perceived exertion (RPE) according to
Borg score
25after each training session. The
intensity target was to achieve a mean heart rate
on 80100% of peak heart rate according to
maximal test on cycle ergometer and the patients
were encouraged to reach Borg score 5 for dyspnea
and 15 for rated perceived exertion. The blood
pressure at rest was measured once a month.
Statistical analysis
The data were analysed using SPSS (version 10.0).
Non-parametric methods were used and the data
are presented as medians along with minimum andmaximum values unless otherwise stated. An
intention to treat analysis was applied (i.e. all
patients completing pre- and post-tests were taken
into the analysis). A lower limit of training
compliance was set to 50% of the training sessions.
The patients who fullled that criterion were also
analysed separately as on treatment group. Differ-
ences between groups were analysed with the non-
parametric KruskallWallis one-way ANOVA (analy-
sis of variance). When the ANOVA showed signi-
cant differences between groups, the Mann
WhitneyU-test was used for pairwise comparisons
between groups. The level of signicance was
dened asPo0.05. Changes within groups were
compared with Wilcoxon matched-pairs signed-
ranks test. Effect-size values (ES) were calculated
to describe overall treatment effects.
30It is
calculated as the difference between before
treatment (T1) and after treatment (T2) divided
by the combined standard deviation for the total
patient group before treatment (SD1). (ES(T1
T2)SD1). ES values are preferably calculated so
that a positive change gives a positive value. The
most common criteria for what is considered to be
a large or a small treatment effect are based on
Cohens work. Values below 0.2 are considered as
no effect, between 0.2 and 0.5 a small effect,
between 0.5 and 0.8 a medium effect and values
above 0.8 are a large effect.
30Sample size was
determined by power analysis (nQuery Advisors
3.0) based on the minimum clinically important
difference (MCID) in the ISWT.31A sample size of 30
subjects (10 subjects per group) was recommended
to attain a power480% with aa-level of 0.05. To
adjust for potential drop-out 30 subjects in the
intervention group and 13 patients in the control
group (i.e. a total of 43 patients) were enrolled.
Results
Two patients (one woman in the control group and
one woman in the land training group) did not
attend the follow up tests and thus were regarded
as drop-outs. Forty-one patients completed all
follow up tests and were included in the intention
to treat analysis. Twelve patients in each training
group fullled the criteria of attending at least 50%
of the training sessions (on treatment). The median
attendance rate among the patients fullling the
criteria was in the water group 31.5 (min18,
max36) and in the land group 30.5 (min23,
max35) of a total of 36 sessions (88% and 85%,
respectively). There were no signicant differences
at baseline in any of the studied parameters
ARTICLE IN PRESS
0 50 100 150
00:00:15 00:15:15 00:30:15 00:45:1512
34
56
7
8
Heart rate for one patient during a water
training session
0 50 100 150
00:00:15 00:15:15 00:30:15 00:45:15
Heart rate (rpm)
12
34
56
7
8
Heart rate for one patient during a land
training session
Heart rate (rpm)
Figure 1The intensity prole during the training
sessions in water and on land, demonstrated with the
heart rate of one patient from each training group. (1)
Warm-up, (2) endurance exercises, (3) leg strength
exercises, (4) endurance exercises, (5) arm strength
exercises, (6) endurance exercises, (7) exercises for
strength in torso, (8) cool-down.
High intensity physical group training in waterFan effective training modality for patients with COPD431

between the groups or between the patients
fullling the training criteria and those who did
not.
The mean heart rate during the training sessions
in both training groups is shown as percent of peak
heart rate inFig. 2. The ratings of dyspnea (010)
and perceived exertion (620) reached on average
4 and 14, respectively, for both training groups.
Both training groups increased their distance
walked in ISWT (signicant in the land group) and
ESWT (signicant in the water group) while the
control group decreased (not signicant) the dis-
tance. The difference after training was slightly
larger for the on treatment group compared to the
intention to treat group. The difference in ISWT
between the control group and the training groups
was signicant when looking at the on treatment
patients but not the intention to treat patients.
The differences in ESWT between the groups were
signicant in both comparisons (Table 2).
During the incremental symptom-limited cycle
ergometer tests both the water and the land
training groups signicantly increased the time
cycled. A signicant increase in mean workload
was found, 6.7, 9.3 and 10.0 W for the control,
water and land groups, respectively. All groups
increased their VO
2peakduring the cycle ergometer
test and the increase was signicant in the water
and the control group (Table 3). The water group
showed a small but signicant increase in peak
heart rate (3 rpm). No changes were found in any
of the groups in peak ventilation or peak lactate
during the cycle ergometer tests.
The mean total score in SGRQ at baseline for the
control, water and land groups were 33.3 (SD 13.5)
units, 40.5 (20.2) units and 44.8 (18.1) units,
respectively. The difference between groups was
not signicant at baseline.Figure 3presents the
change in units after intervention with intention to
treat analysis. The water group showed a slight,
non-signicant, decrease in total score (improve-
ment,3.6 units) in SGRQ. The control groupshowed a signicant increase in total score (dete-
rioration,5.3 units), and that change was also
signicant compared to the training groups,
P0.034. The water group showed a signicant
decrease in activity score (5.1 units), which was
also a signicant improvement compared to the
other two groups (P0.009) (Fig. 3).
The water group showed a signicant improve-
ment in physical healthFPCS (physical component
score) from 33 to 39 in SF-36, and this change was
signicant compared to the two other groups,
P0.041 (intention to treat analysis). The change
in the patients who fullled the criteria of training
attendance was slightly greater, from 34 to 42.
Figure 4presents the results in the PCS together
with normal values for a healthy Swedish popula-
tion over 65 years of age. In the mental health
score all groups were on the same level as the
healthy population at baseline and no change
appeared after intervention.
The effect-size values (ES) for the walking tests,
SGRQ and SF-36 in the intention to treat groups are
presented inTable 4. According to these calcula-
tions the land group showed a small positive effect
in ISWT (0.33) and the water group showed a
medium positive effect in ESWT (0.68). In SGRQ the
control group showed negative ES values for all
dimensions and the symptoms, activity and total
scores are considered as small changes (0.3 to
0.46). On the opposite the water group showed
small positive ES values in the activity, impact and
total scores (0.20.28). In the between group
comparisons the difference was signicant in the
activity score (P0.056 in the total score). In SF-36
the water group achieved an effect which was
considered to be a medium positive change in PCS
(0.61). In the between group comparisons there
were no signicant differences (P0.062 in PCS).
The results from the activity level questionnaire
indicated that the control group had lowered their
level of daily activity during the study period.
The questions about health status indicated
that both training groups had more exacerbations
that demanded treatment with antibiotics
during the intervention period compared to the
control group.
Discussion
In most previous training studies on patients with
COPD the participants had individually designed
training programs.
79This study showed that 12
weeks of physical group training in water as well as
on land led to an improved exercise performance in
ARTICLE IN PRESS
0 20 40 60 80 100 120
1710
Weeks of trainin
g
% peak heart rate
Water
Land
4
Figure 2Percent of peak heart rate during the training
sessions in both training groups. (Peak heart rate
achieved during maximal cycle ergometer test pre
training).
432K. Wadell et al.

ARTICLE IN PRESS
Table 2Results from the walking tests at baseline and after 3 months intervention in the control group and the training groups. Analysis of all patients in thestudy
(Intention to treat) and analysis of patients fullling the training attendance criteria (On treatment) are presented. Median values (minmax) at baseline, at 3
months follow up, and the differences are given. Comparisons within and between group are outlined. Ns; no signicance.
Control group Water group Land group
(n12) Intention to treat
(n15)On treatment
(n12)Intention to treat
(n14)On treatment
(n12)Between group
comparisons
ISWT (m) Baseline 345 (180550) 270 (200540) 270 (200540) 350 (130570) 380 (130570) ns
3 months 320 (200500) 340 (150540) 345 (260540) 390 (140590) 420 (140590)
Within group
comparisonns ns nsP0.008P0.003
Difference5(11080) 20 (140110) 55 (90110) 20 (20130) 25 (0130)P0.03
a
Baseline3 moP0.008
b
ESWT (m) Baseline 1047 (1161538) 458 (1331364) 562 (1331364) 576 (851905) 686 (851905) ns
3 months 599 (1761446) 1060 (3151846) 1319 (3151846) 512 (2091905) 747 (2091905)
Within group
comparisonnsP0.001P0.002 ns ns
Difference40 (890444) 164 (81454) 179 (81454) 53 (473704) 53 (473704)P0.001
c
Baseline3 moP0.009
d
P0.001
e
P0.007
f
Wilcoxon Signed Ranks test was used for comparisons within groups. KruskalWallis and MannWhitneyU-test was used for comparisons between groups.aControl and water groupFon treatment.bControl and land groupFon treatment.cControl and water groupFintention to treat.dWater and land groupFintention to treat.eControl and water groupFon treatment.fWater and land groupFon treatment.
High intensity physical group training in waterFan effective training modality for patients with COPD433

ARTICLE IN PRESS
Table 3Results from the cycle ergometer tests at baseline and after 3 months intervention in the control group and the training groups. Analysis of all patients in
the study (Intention to treat) and analysis of patients fullling the training attendance criteria (On treatment) are presented. Median values (minmax) at baseline,
at 3 months follow up, and the differences are given. Comparisons within and between groups are outlined. Ns; no signicance.
Control group Water group Land group
(n12) Intention to treat
(n15)On treatment
(n12)Intention to treat
(n14)On treatment
(n12)Between group
comparisons
Time cycled (s) Baseline 495 (2301260) 520 (360720) 520 (380720) 540 (2601170) 540 (3501170) ns
3 months 525 (2401440) 580 (380900) 595 (390900) 575 (2701300) 595 (3901300)
Within group
comparisonnsP0.004P0.008P0.033P0.016
Difference 20 (110180) 40 (30180) 85 (30180) 25 (50170) 40 (30170) ns
Baseline3 mo
Load
peak
(W) Baseline 60 (40140) 60 (4080) 60 (6080) 60 (40140) 60 (40140) ns
3 months 60 (40160) 80 (60100) 80 (60100) 80 (40160) 80 (60160)
Within group
comparisonP0.046P0.008P0.014P0.008P0.008
Difference 0 (020) 0 (020) 10 (020) 10 (020) 20 (020) ns
Baseline3 mo
VO
2 peak
(ml
kgmin)Baseline 16.6 (10.824.9) 15.6 (13.023.1) 15.5 (13.223.1) 17.7 (13.327.3) 18.9 (14.627.3) ns
3 months 18.0 (11.528.7) 16.9 (14.026.4) 16.9 (14.026.4) 17.7 (13.334.1) 19.8 (13.934.1)
Within group
comparisonP0.018P0.008P0.004 ns ns
Difference 0.7 (0.73.8) 1.5 (1.93.5) 2.1 (0.53.5) 0.6 (3.96.8) 0.6 (3.96.8) ns
Baseline3 mo
Wilcoxon Signed Ranks test was used for comparisons within groups. KruskalWallis and MannWhitneyU-test was used for comparisons between groups.
434K. Wadell et al.

both walking tests and cycle ergometer tests. The
two different training groups also showed a
preserved quality of life according to the SGRQ ascompared to the control group who deteriorated.
Furthermore the group training in water improved
the endurance according to the ESWT even more
than the group training on land. The water group
also improved their activity score in the SGRQ and
their physical health according to the SF-36 and
that was signicant compared to both the control
and the land training group.
The nding that physical training is effective in
COPD patients is in accordance with previous
studies, that have shown that strength training as
well as endurance training should be included in
the training programmes
8,9and that interval train-
ing is of benet.7The programmes in our study
included both strength and endurance exercises
and the sessions were designed with intervals in
accordance with the music and as described in the
methods.
The reason why the land group, not the water
group, increased the distance walked in ISWT, and
why the water group, not the land group, increased
the distance walked in ESWT is not clear. The design
of the training programme was the same in the two
training groups with the same amount of endur-
ance, strength and mobility exercises. Physiothera-
pists led the training and, as far as possible, the
same physiotherapist led both land and water
training to avoid the impact of different leader
personalities. The mean heart rate during the
training sessions (Fig. 2) shows that the intensity
level complies with the goal 6090% of HR
maxset by
the American College of Sports Medicine (ACSM) for
improving aerobic tness.
32The design of the
walking tests could possibly be one explanation to
ARTICLE IN PRESS
-6 -4 -20
2 4 6
8 10 12
Control Land
Groups
Change in SGRQ (units)
SymptomsActivityImpactTotal
*
Water
Figure 3Change in St. Georges Respiratory Question-
naire (SGRQ) after intervention. Intention to treat
analysis. Mean values presented.
, signicant within
group,P0.015, *, signicant within group,P0.046.
0 5 10 15 20 25 30 35 40 45 50Control Land
Groups
SF-36 score
PCS pre PCS post PCS normal
*
Water
Figure 4Physical health according to SF-36 (PCSFphy-
sical component score) before and after intervention
compared to a normal population. Intention to treat
analysis. Mean values presented. *, signicant within
group,P0.015.
Table 4Mean effect-size values (ES) and 95 % CI for walking tests (ISWT, ESWT) and health related quality of life,
HRQoL (SGRQ, SF-36) in the three groups. TheP-value presents the between group differences. Ns; no
signicance.
Outcomes Control (n12) Water (n15) Land (n14)P-value
ES 95 % CI ES 95 % CI ES 95 % CI
Walking tests
ISWT0.08 (0.350.19) 0.16 (0.160.49)0.33(0.090.56) ns
ESWT0.30(0.780.17)0.68(0.221.14) 0.06 (0.230.35) 0.003
SGRQ
Symptoms0.37(0.880.14)0.02 (0.560.52)0.06 (0.510.39) ns
Activity0.42(0.880.05)0.28(0.000.55)0.17 (0.520.19) 0.018
Impact0.14 (0.330.05)0.21(0.160.57) 0.07 (0.350.48) ns
Total0.30(0.500.09)0.20(0.130.53) 0.03 (0.360.30) ns
SF-36
PCS0.14 (0.620.34)0.61(0.101.13) 0.02 (0.480.52) ns
MCS 0.00 (0.370.36)0.07 (0.600.46)0.10 (0.540.18) ns
The effect-size values of clinical relevance are indicated with bold style.
High intensity physical group training in waterFan effective training modality for patients with COPD435

the results. The speed in the ESWT was decided
from the result of the ISWT, it should correspond to
85% of the predicted VO
2achieved in ISWT. An
improvement in ISWT could lead to a higher walking
speed in ESWT, which in it self is an improvement,
but may have lead to difculties for the patient to
manage for a longer period.
The patients training in water in the present
study attained lower heart rates compared to the
land group throughout the training period (Fig. 2),
although they rated their dyspnea and perceived
exertion as high as the land group (4 and 14 on the
Borg score). Head-out immersion in water leads to
a central shift of blood volume from the peripheral
to the intrathoracic vascular bed and studies have
reported lower heart rates in water compared to
the same exercise intensity on land.
33,34Agostini
et al.35found that the functional residual capacity
(FRC) is decreased by almost the half, the vital
capacity (VC) is decreased with 9% and the residual
volume (RV) is decreased with about 16% during
head-out water immersion. In patients with COPD
the FRC and RV are often increased due to
pathological changes in the lungs. This increases
the work of breathing and contributes to the
increased dyspnea that many of the patients suffer
from. The fact that FRC and RV are decreased
during head-out water immersion could possibly
decrease the sense of dyspnea and facilitate the
accomplishment of physical exercises in water.
Further studies are desirable to investigate if this
effect explains the difference in results between
the water group and the land group.
The signicant increase of 25 m in ISWT in the
land group is not considered to be of clinical
relevance since the minimum clinically important
difference (MCID) for ISWT is 48 m.
31On the other
hand, the increase in ESWT for the water group
(179 m) is of such a magnitude that it could be
considered as a clinically important difference,
although comparable data for ESWT is not yet
available. The water and land groups increased
their peak workload during the cycle ergometer
test with mean values of 9.3 and 10.0 W, respec-
tively, which is above the limit of clinical relevance
in patients with COPD (8.3 W) as suggested by
Lacasse et al.
36The control group signicantly
increased their workload with a mean value of
6.7 W and their VO
2peakwith 0.7 mlkg min but it
can be questioned if these increases are clinically
important.
A clinically important difference was also
achieved in the water group in the activity score
in SGRQ where the group lowered the score by 5.1
units. Four units is considered to be the threshold
of clinically signicant change.
37The control groupincreased their total score with 5.3 units, which
consequently is a clinically important reduction in
the health related quality of life. Compared to
other groups of COPD patients presented in
previous studies
26,38the results in SGRQ at base
line seem to be slightly better in our study group.
When comparing the studied group of COPD
patients with a normal Swedish population over
the age of 65 years,
28we found that the patients
had similar mental scores but decreased physical
scores according to the generic SF-36 question-
naire. The increase of 6 points in the water training
group (8 points in the on treatment group) could be
compared with the results from Kosinski et al. who
found that an increase of 4.4 points in PCS (SF-36) is
a minimum clinical important difference in patients
with rheumatoid arthritis.
39
When analysing the effect-size values we found
that these values agree quite well with the actual
test results (Table 4). The water group achieved
effect-sizes between 0 and 0.7, the land group
between 0 and 0.3, and the control group pre-
sented effect-sizes between 0 and0.4. These
results can be compared with the meta-analysis
from Lacasse et al. who presented effect-sizes in
exercise capacity and HRQoL between 0.3 and 0.8
after pulmonary rehabilitation
36and with a re-
search synthesis from Cambach et al.40who
presented effect-sizes between 0.4 and 1.2. The
somewhat lower effect-sizes found in the present
study might be explained by the difference in
intervention, which in this study consisted of
physical training only, and not multidisciplinary
rehabilitation programmes which were focused on
in Cambach et al.s meta-analysis.
According to the activity level questionnaire the
patients in the control group tended to decrease
their activity level during the intervention period.
Aside from the deterioration of a chronic disease,
one explanation could be the climate, which tends
to worsen during the time of year of the study
(SeptemberNovember) and does not stimulate
outdoor activities. This decrease in activity level
could possibly correspond to the decrease in quality
of life according to the SGRQ. Regarding the
questions about health status it was shown that
the patients in the training groups tended to have a
higher rate of exacerbations and use of antibiotics
compared to the control group. One hypothesis is
that infections are more easily spread in groups as
when patients gather together for training, but this
has to be further elucidated. Despite the higher
number of exacerbations the patients in the
training groups managed to increase their physical
capacity and keep or improve their health related
quality of life during the period.
ARTICLE IN PRESS
436K. Wadell et al.

In individually tailored exercise programs, which
most previous studies have focused on,79the
number of cycle ergometers, treadmills or strength
exercises machines available at the rehabilitation
centre restricts the number of patients training at
the same time. The results from the present study
show that group training, with 15 patients in each
group led by one physiotherapist, is effective. The
patients can keep the intensity, measured by Borg
ratings and heart rate, on an acceptable level.
Although no calculations on costs were made,
this kind of training can be considered to be cost
effective, since several patients train together
under supervision from one leader, without the
need of equipment other than the halls. Further-
more the psychosocial aspects of patients getting
together in a group activity could not be ignored as
a positive factor.
In this study high intensity physical group training
was shown to be of benet for patients with COPD.
A new nding with the present study is that, with
comparable exercise intensity, group training in
water shows additional benets in physical capacity
and experienced physical health compared to group
training on land. These positive results achieved by
the water group may contribute to a new effective
training modality for the increasing number of
COPD patients.
Acknowledgements
This work was supported by grants from the
Swedish Heart- and Lung Foundation, the National
Patient Federation for Heart- and Lung diseases in
Sweden, and the Swedish V(
ardal foundation.
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