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High-Intensity Intermittent Swimming Improves Cardiovascular Health Status for Women with Mild Hypertension

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To test the hypothesis that high-intensity swim training improves cardiovascular health status in sedentary premenopausal women with mild hypertension, sixty-two women were randomized into high-intensity (n = 21; HIT), moderate-intensity (n = 21; MOD), and control groups (n = 20; CON). HIT performed 6-10 × 30 s all-out swimming interspersed by 2 min recovery and MOD swam continuously for 1 h at moderate intensity for a 15-week period completing in total 44 ± 1 and 43 ± 1 sessions, respectively. In CON, all measured variables were similar before and after the intervention period. Systolic BP decreased (P < 0.05) by 6 ± 1 and 4 ± 1 mmHg in HIT and MOD; respectively. Resting heart rate declined (P < 0.05) by 5 ± 1 bpm both in HIT and MOD, fat mass decreased (P < 0.05) by 1.1 ± 0.2 and 2.2 ± 0.3 kg, respectively, while the blood lipid profile was unaltered. In HIT and MOD, performance improved (P < 0.05) for a maximal 10 min swim (13 ± 3% and 22 ± 3%), interval swimming (23 ± 3% and 8 ± 3%), and Yo-Yo IE1 running performance (58 ± 5% and 45 ± 4%). In conclusion, high-intensity intermittent swimming is an effective training strategy to improve cardiovascular health and physical performance in sedentary women with mild hypertension. Adaptations are similar with high- and moderate-intensity training, despite markedly less total time spent and distance covered in the high-intensity group.
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Research Article
High-Intensity Intermittent Swimming Improves Cardiovascular
Health Status for Women with Mild Hypertension
Magni Mohr,1,2 Nikolai Baastrup Nordsborg,3Annika Lindenskov,4Hildigunn Steinholm,5
Hans Petur Nielsen,6Jann Mortensen,7,8 Pal Weihe,9and Peter Krustrup1,3
1Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke’s Campus, University of Exeter, Exeter EX12LU, UK
2Department of Food and Nutrition, and Sport Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
3Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen,
2100 Copenhagen, Denmark
4e Faroese Confederation of Sports and Olympic Committee, 100 Torshavn, Faroe Islands
5Department of Nursing, Faculty of Natural and Health Sciences, University of the Faroe Islands, 100 Torshavn, Faroe Islands
6Southern Hospital, e Faroese Hospital System, Faroe Islands
7Department of Medicine, e Faroese National Hospital, 100 Torshavn, Faroe Islands
8Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Copenhagen University Hospital,
2100 Copenhagen, Denmark
9Department of Occupational Medicine and Public Health, e Faroese Hospital System, 100 Torshavn, Faroe Islands
Correspondence should be addressed to Magni Mohr; m.mohr@exeter.ac.uk
Received  January ; Revised  March ; Accepted  March ; Published  April 
Academic Editor: David G. Behm
Copyright ©  Magni Mohr et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
To test the hypothesis that high-intensity swim training improves cardiovascular health status in sedentary premenopausal women
with mild hypertension, sixty-two women were randomized into high-intensity (𝑛=21; HIT), moderate-intensity (𝑛=21;MOD),
and control groups (𝑛=20; CON). HIT performed – × s all-out swimming interspersed by  min recovery and MOD swam
continuously for h at moderate intensity for a -week period completing in total 44±1and 43±1 sessions, respectively. In CON, all
measured variables were similar before and aer the intervention period. Systolic BP decreased (𝑃 < 0.05)by6±1and 4±1mmHg
in HIT and MOD; respectively. Resting heart rate declined (𝑃 < 0.05)by5±1bpmbothinHITandMOD,fatmassdecreased
(𝑃 < 0.05)by1.1 ± 0.2 and 2.2 ± 0.3 kg, respectively, while the blood lipid prole was unaltered. In HIT and MOD, performance
improved (𝑃 < 0.05) for a maximal  min swim (13 ± 3%and22 ± 3%), interval swimming (23 ± 3%and8±3%), and Yo-Yo IE
running performance (58 ± 5%and45 ± 4%). In conclusion, high-intensity intermittent swimming is an eective training strategy
to improve cardiovascular health and physical performance in sedentary women with mild hypertension. Adaptations are similar
with high- and moderate-intensity training, despite markedly less total time spent and distance covered in the high-intensity group.
1. Introduction
Arterial hypertension is associated with cardiovascular mor-
bidity and mortality, and it is well known that the risk of
arterial hypertension is markedly elevated by obesity and an
inactive lifestyle [,]. Additionally, there is strong evidence
that exercise training lowers arterial blood pressure, improves
aerobic tness, and counteracts several other cardiovascular
risk factors related to increased morbidity in patients with
mild to moderate hypertension [,], but it is still debated
whether the magnitude of training response is related to
exercise mode and the type of training performed.
e vast majority of studies investigating the relation-
ship between exercise training and cardiovascular health
responses have applied running, cycling, or team sports
participation as the training intervention [], whereas
few have examined the eects of dierent aquatic exercise
regimes []. Swimming may be considered a good choice
Hindawi Publishing Corporation
BioMed Research International
Volume 2014, Article ID 728289, 9 pages
http://dx.doi.org/10.1155/2014/728289
BioMed Research International
of training especially for obese middle-aged and elderly
individuals because it involves minimum weight-bearing
stress, which may reduce the risk of injury. In addition,
swimming engages the upper body musculature where the
potential for metabolic adaptation can be hypothesized to
be larger than in the postural musculature. However, little
information is available concerning the eects of regular
swimming exercise training on the cardiovascular health pro-
le. Nualnim and coworkers [] demonstrated that  wks of
regular – min continuous moderate-intensity swimming
lowered systolic blood pressure (SBP) by  mmHg in adults
older than  yrs with mild hypertension. e swimming
exercise training also resulted in a % increase in carotid
artery compliance, as well as improvement in ow-mediated
dilation and cardiovagal baroreex sensitivity []. However,
no studies have compared dierent swim training regimes in
sedentary women suering from mild to moderate arterial
hypertension.
Lack of time is a common explanation why people fail
to participate continuously in traditional exercise regimes
based on prolonged session of moderate-intensity training.
erefore, it is of interest to explore the health eects of
short-duration exercise training protocols. Numerous nd-
ings indicate that brief high-intensity training appears to be
ecient in improving aerobic tness and other physiological
adaptations of importance for the cardiovascular health status
in untrained individuals [,,]. Moreover, short-term
sprint training apparently provoked similar muscle metabolic
and exercise performance adaptations as prolonged submax-
imal training protocols [,]. ese studies challenge the
pronouncement by sports medicine authorities that –
 min of moderate-intensity exercise per week is required
to maintain a healthy lifestyle [,]andsupporttheidea
that  min of vigorous exercise may be sucient []. For
example, Nybo et al. [] found dierences in the adaptive
response within several indicators of cardiovascular health
to short-duration high-intensity intermittent running com-
pared to prolonged submaximal continuous running, includ-
ing more pronounced eects on maximal oxygen uptake for
the high-intensity training group. is study was performed
on sedentary men, while Metcalfe et al. [] demonstrated
marked improvements in aerobic capacity and metabolic
health aer intensied cycling in sedentary participants of
both genders. However, it is currently unclear to what extent
women respond to submaximal prolonged versus short-
term high-intensity swim training. Gender dierences have
beenshowntobepresentwithinarangeofphysiological
adaptations to exercise training [,]. For example, women
appear to display smaller reductions in blood pressure aer
exercise training interventions in comparison to their male
counterparts [,,]. It is therefore of importance to inves-
tigate the eect of two types of swimming exercise training
on the cardiovascular disease risk prole in sedentary women
with mild to moderate hypertension.
us, the objective of the present study was to test the
hypothesis that high-intensity swim training is an ecient
strategy to reduce blood pressure and improve the cardiovas-
cular health prole in sedentary premenopausal women with
mild to moderate hypertension.
2. Materials and Methods
Sixty-two sedentary premenopausal women with mild to
moderate arterial hypertension were recruited for the study.
e subjects were selected among  volunteers based on
training history, medication, blood pressure, and body mass
index. A total of  participants were recruited.  took part in
the present study and  were randomly assigned to a football
group being part of another study []. In addition, the
control group ( participants) in the present study was also
thecontrolsintheabove-mentionedstudybyMohretal.[].
e study was approved by the ethical committee of the Faroe
IslandsaswellastheSportandHealthSciencesResearch
Ethics Committee at the University of Exeter, Exeter, UK, and
conducted in accordance with the Declaration of Helsinki
(). Aer being informed verbally and in writing of the
experimental procedures and associated risks, all participants
gave their written consent to take part in the study.
2.1. Experiment Design. e study was designed as a random-
ized controlled trial. Aer initial testing of the  volunteers,
 participants were enrolled in the present study based
on selection criteria being a sedentary lifestyle for the last
two years, mild hypertension (mean arterial pressure –
 mmHg), and a body mass index >. Participants treated
with adrenergic beta-antagonists were excluded. Participants
using diuretics and ACE inhibitors (𝑛=4) were not excluded
from the study, but none of the four subjects changed their
medication during the intervention period. e participants
were randomized into a high-intensity intermittent swim-
ming training group (HIT: age 44 ± 2 (–) ±SEM (range)
yrs; height 164 ± 1cm; weight 76.5 ± 1.9 kg; 𝑛=21), a
moderate-intensity continuous swimming group (MOD: age
46 ± 2 (–) yrs, height 165 ± 1 cm, weight 83.8 ± 4.3kg;
𝑛=21), and a control group (CON: age 45 ± 2 (–) yrs,
height 166 ± 1 cm, weight 76.4 ± 2.6kg; 𝑛=20). e training
groups took part in two types of swimming training with
 training sessions per week for  wks, while CON had no
training or lifestyle changes in the same period. ere were
nodropoutsfromthestudy,butonesubjectintheMOD
group suered from aquatic phobia and was therefore moved
to CON. All subjects performed an intermittent swimming
sprint test and an endurance swimming test, as well as an
intermittent running test with heart rate recordings, and
had their blood pressure, resting heart rate (RHR), body fat
content, and blood cholesterol measured before and aer the
intervention. Finally, basic anthropometrical measurements
were performed. e pre- and posttests were conducted in
the same order. e posttness tests were conducted – h
aer the last training session. e training was continued
until the last measurement was obtained. e dietary intake
was not controlled during the training period and the testing
periodswerenottimedinrelationtothemenstrualcycle.
2.2. Training Intervention. e HIT participants completed
in total 44 ± 1 (–) training sessions over the -week
intervention period corresponding to 2.9 ± 0.1 (.–.)
sessions per week. Every session lasted – min (– min
BioMed Research International
of eective swimming) and consisted of –  s all-out
free-style swimming (front crawl) intervals interspersed by
 min of passive recovery aer training principles previously
described [,]. In the rst  wks of training the partici-
pants completed  intervals, the following wks included 
intervals, and the nal  wks consisted of  all-out swimming
intervals. e MOD group completed a total of 43 ±1 (–)
training sessions over  wks corresponding to 2.9 ± 0.1 (.–
.) training sessions per week. All MOD training sessions
lasted  h and consisted of continuous front crawl swimming
where the participants were encouraged to swim as far as
possible in every session. Five trained swimming coaches
were present during all training sessions in order to give
technical advice and control the intensity and duration of
the training and to secure a safe training environment. Heart
rate was measured during one training session in week  and
one session in week  of the training intervention, and the
swimming distance was noted in every session.
2.3. Blood Pressure and RHR Measurements. e participants
reported to the hospital at : a.m. aer an overnight
fast and rested in a supine position for  h. Systolic blood
pressure (SBP) and diastolic blood pressure (DBP) were
measured according to standard procedures []usingan
automatic BP monitor (HEM-; OMRON, IL, USA) once
every  min over the  h resting period. e average of the
four measurements was used as the test result. Mean arterial
pressure (MAP) was calculated as / SBP + / DBP. Resting
HR was measured during the same time intervals as the BP
recordings.
2.4. Resting Blood Sampling. A resting blood sample was
collected under standardized conditions from an antecu-
bital vein between : and : a.m. aer an overnight
fast using venipuncture technique. e blood was rapidly
centrifuged for  s and analyzed by an automatic analyzer
(Cobas Fara, Roche, France) using enzymatic kits (Roche
Diagnostics, Germany) for determination of total cholesterol,
LDL-cholesterol, HDL-cholesterol, and triglyceride levels.
2.5. DXA Scanning. Whole-body body fat and lean body
mass were evaluated by total body DXA scanning (Norland
XR-, Norland Corporation, Norway). e body was seg-
mented in accordance with standard procedures to evaluate
regional fat distribution [], and all analyses were performed
using Illuminatus DXA soware (Norland Corporation, Nor-
way).eeectiveradiationdosewas<. mSv per scan.
2.6. Exercise Performance Testing. e participants in HIT
and MOD performed two front crawl swimming tests before
and aer intervention. To evaluate if the high-intensity
training improved the ability to repeatedly perform high-
intensity swimming more than moderate-intensity training,
a repeated swimming sprint test (RSST) composed of 4×25m
sprinting starting every  s was performed. e participants
were instructed to swim each  m as fast as possible. To
evaluate if continuous training was more ecient in improv-
ing continuous swimming performance, a  min continuous
swimming test was performed. Swimmers were instructed
to complete the largest possible swimming distance during
the  min. Swim testing was performed in a  m pool at a
water temperature of C. To evaluate if the swim-training
intervention improved exercise capacity in a land-based
activity, all participants additionally completed a shuttle-run
test. e Yo-Yo Intermittent Endurance test, level  (Yo-Yo
IE), was completed before and aer the training period. e
Yo - Yo I E  t e s t c o n s i s t s o f 2×20m shuttle runs interspersed
by a  s recovery period consisting of 2×2.5mjogging(see
[]). ere is a gradual speed progression during the test,
whichiscontrolledbyaCDplayer[]. e participants
run until the point of exhaustion dened as the second
timetheyareunabletocompletethe2×20mrunsat
therequiredpace[]. Maximum heart rate (HRmax)was
determined during the test as previously described []. e
preintervention test was performed within ten days of the
rst training and the postintervention test four days aer
the last training session. e tests were conducted indoor
on a wooden surface at environmental temperatures between
 and C. e tests were preceded by a short warm-
up period consisting of the rst three of the 2×20m
shuttle runs, followed by a min recovery period before
the exhaustive test. Heart rate was measured continuously
during the tests using Polar Vantage NV chest belt monitor
weighing  g (Polar Electro Oy, Kempele, Finland), and
HRmax was determined as previously described []. e pre-
and postintervention tests were conducted at the same time
of day. All participants were familiarized to all test procedures
prior to the experiment according to guidelines presented in
Bradley et al. []. e participants were instructed to avoid
exercise training and intake of alcohol the day prior to the
testing and nutritional items rich in caeine on the day of
testing. In addition, the participants were also instructed to
notethefoodintakeandfollowsimilarnutritionalguidelines
during the last  h before both test periods.
2.7. Hip and Waist Circumference and Body Weight. Hip and
waist circumference was assessed as described by Kharal et al.
[]. Body mass was assessed by weighing the participant. e
weighing was performed in the morning aer an overnight
fast using a platform scale (Ohaus, Germany).
2.8. Statistical Analyses. Data are presented as means ±SEM.
Between- and within-group data were evaluated both by two-
factor mixed ANOVA design and with one-way ANOVA on
repeated measurements. When a signicant interaction was
detected, data were subsequently analyzed using a Newman-
Keuls post hoctest. Signicance level was 𝑃 < 0.05.
3. Results
3.1. Heart Rate and Distance Covered during Training. Aver-
age mean and peak HR during HIT training in the rst and
last weeks of the intervention was 158 ± 5 and 176 ± 2bpm,
respectively, corresponding to 85.5 ± 1.1 and 95.3 ± 1.1%
HRmax, respectively, which was higher (𝑃 < 0.05)than
average values in MOD (132 ± 4 and 144 ± 3 bpm equivalent
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to 72.5 ± 0.9 and 79.1 ± 1.0%HR
max). No dierences in
heart rate between the rst and last weeks of training were
detectable within either training group. In HIT the average
swim distance per session during the rst week was 131±7 m
and increased (𝑃 < 0.05)to269 ± 10mduringthelast
training week. Average swim distance per swimming interval
increased (𝑃 < 0.05)by28 ± 6%fromthersttothelast
training week. In MOD the average swim distance per session
was 1177 ± 41m during the rst training week and was
increased (𝑃 < 0.05)to1787 ± 35 m(52.8 ± 3.2%) during
the last training week.
3.2. Blood Pressure and Resting Heart Rate. Prior to the
intervention period, SBP and DBP were 138 ± 4 and 86 ±
3mmHg in HIT, 142 ± 4 and 87 ± 2mmHg in MOD, and
134 ± 4 and 82 ± 2mmHg in CON, respectively, with no
dierences between groups. In HIT, SBP decreased (𝑃<
0.05)by6±1mmHg (4±1%) during the  wk intervention
period (Figure ), while the MOD group displayed a decrease
(𝑃 < 0.05)of4±1mmHg (3±1%) in SBP. DBP was similar
before and aer intervention for HIT and MOD (Figure ).
No signicant changes took place in neither SBP nor DBP in
CON (0±0and 0±0mmHg, Figure ). MAP was 103± 4 and
99 ± 2 mmHg before training in HIT and CON, respectively,
and tended (𝑃 = 0.06)todecrease(3±1mmHg, 3±1%) aer
intervention in HIT, with no changes in MOD or CON (−1±0
and 0±0mmHg, Figure ). Sixteen of the twenty-one subjects
in HIT experienced a decline in MAP during the intervention
period, with corresponding numbers in MOD being thirteen
out of twenty-one and eleven out of twenty in CON.
Resting HR decreased (𝑃 < 0.05)by5±1bpmoverwks
both in HIT (76 ± 2 to 71 ± 2 bpm) and MOD (78 ± 3 to 73 ±
2bpm), whereas it was not signicantly altered in CON (77±2
and 74 ± 2 bpm).
3.3. Body Fat, Lean Body Mass, and Anthropometry. Tot a l
body fat percentage was 43.1± 1.1,44.1±1.2,and41.0 ±1.2%
before training in HIT, MOD, and CON, respectively, and
decreased (𝑃 < 0.05)byasimilarmagnitudeto41.4± 1.2 and
42.1±1.0%inHITandMOD,respectively,withnochangein
CON (41.5± 1.1%). Total fat mass decreased by 1.1± 0.2 and
2.2± 0.3kg (𝑃 < 0.05) in HIT and MOD, respectively, during
thewksbutremainedsimilarinCON(Figure ). Lean
body mass increased (𝑃 < 0.05)by1.7 ± 0.3 and 1.3 ± 0.3 kg
in HIT and MOD, respectively, with no signicant changes in
CON (Figure ). Hip circumference was lowered (𝑃 < 0.05)
in MOD (108 ± 2 to 105 ± 2cm) but not in HIT (104 ± 1
to 103 ± 2cm) and CON (104 ± 1 to 103 ± 1cm). Waist
circumference declined (𝑃 < 0.05)inHIT(86±2 to 83±2 cm)
and MOD (94 ±3 to 89± 3cm) but was stable in CON (84±2
and 82±2 cm). Total body mass was lowered (𝑃 < 0.05)over
 wks in HIT (76.5±1.9 to 75.9±2.1 kg) and MOD (83.8±4.3
to 82.4±4.0 kg), but remained similar in CON (76.4± 2.6 and
77.3 ± 2.2 kg) (Figure ).
3.4. Plasma Cholesterol and Triglycerides. To t a l p l a s ma
cholesterol was 5.6 ± 0.2,6.0 ± 0.2,and5.3 ± 0.2 mmolL−1
before the training intervention in HIT, MOD, and CON,
CON MOD HIT
Systolic blood pressure (mmHg)
0
130
135
140
145
150
(a)
0wks
15 wks
Diastolic blood pressure (mmHg)
0
70
75
80
85
90
95
CON MOD HIT
(b)
F : Systolic and diastolic blood pressure before and aer
 wks with thrice-weekly training sessions of hig h-intensity swim-
ming (HIT) and moderate-intensity swimming (MOD) in com-
parisontoaninactivecontrolgroup(CON).Dataarepresented
as means ±SEM. # denotes signicant within-group dierences.
denotes signicant dierence between the training groups and
CON.
respectively, and was similar aer the intervention period
(Table ). HDL and LDL cholesterol was 1.4±0.1and 3.7±0.2,
1.4 ± 0.1 and 3.9 ± 0.2,and1.4 ± 0.1 and 3.5 ± 0.2 mmolL−1
before training in HIT, MOD, and CON, respectively, and was
unchanged aer the intervention period (Ta b l e  ). Plasma
triglyceride was 1.1 ± 0.1,1.4 ± 0.1,and1.0 ± 0.1 mmolL−1
in HIT, MOD, and CON before training, but was unchanged
aer the training intervention (1.0 ± 0.1,1.3 ± 0.2,and1.3 ±
0.2mmolL−1).
3.5. Performance Testing. Before the training period, HIT
and MOD covered 306 ± 15 and 305 ± 16 m, respectively,
during the  min maximal swim. Aer the training period,
performance was increased (𝑃 < 0.05)inHITandMOD
by 13 ± 3%and22 ± 3%, respectively, resulting in a
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T : Plasma total, HDL, and LDL cholesterol (mmolL−1) before and aer a  wks intervention period in HIT, MOD, and CON.
Total cho l e s t e r o l HDL LDL
Before Aer Before Aer Before Aer
HIT 5.6 ± 0.2 5.5 ± 0.2 1.4 ± 0.1 1.4 ± 0.1 3.7 ± 0.2 3.6 ± 0.2
MOD 6.0 ± 0.2 5.8 ± 0.3 1.4 ± 0.1 1.5 ± 0.1 3.9 ± 0.2 3.8 ± 0.3
CON 5.3 ± 0.2 5.4 ± 0.2 1.4 ± 0.1 1.3 ± 0.1 3.5 ± 0.2 3.4 ± 0.2
Data are expressed as means ±SEM.
Fat mass (kg)
0
28
30
32
34
36
38
40
42
CON MOD HIT
(a)
Lean body mass (kg)
0
36
38
40
42
44
46
48
50
0wks
15 wks
CON MOD HIT
(b)
F : Changes in body composition, including fat mass, lean
body mass, and total body weight aer  wks with thrice-weekly
training sessions of high-intensity swimming (HIT) and moderate-
intensity swimming (MOD) in comparison to an inactive control
group (CON). Data are presented as means ±SEM. denotes
signicant dierence between the training groups and CON.
total distance of 342 ± 14mand368 ± 15 m(Figure (a)).
e improvement in MOD tended (𝑃 = 0.07)tobehigher
than in HIT. Mean accumulated swimming time in the
25m repeated sprint test was 153 ±9 and 141±5sinHITand
MOD, respectively, before the intervention. Aer training,
accumulated swimming time was reduced (𝑃 < 0.05)inboth
groups by 23 ± 3 and 8±3%, respectively, reaching 116 ± 7
and 129±6 s. HIT reduced their accumulated swimming time
more (𝑃 < 0.05)thanMOD(Figure (b)).
Yo-Yo IE performance before intervention was –
 m in the three groups (𝑃 > 0.05)andincreased(𝑃 < 0.05)
similarly by 58 ± 5 and 45 ± 4% aer training in HIT and
MOD, respectively, with no changes in CON (Figure (a)).
HR aer the initial ve 2×20mrunswas92.5 ± 1.1,
94.1 ± 1.0,and92.3 ± 1.0%HR
max before training in HIT,
MOD, and CON, respectively, but was reduced (𝑃 < 0.05)
similarly by 4.5± 0.5 and 3.5±0.4% aer intervention in HIT
and MOD, respectively (88.0 ± 1.4 and 90.6 ± 1.2%HR
max,
resp.) whilst HR remained similar in CON (93.2 ± 0.7%
HRmax;Figure (b)). No dierence was detected in shuttle-
run performance or heart rate response between HIT and
MOD.
4. Discussion
e present study is the rst to examine if two dierent
types of swim training can improve the cardiovascular health
prole and land-based exercise capacity in sedentary pre-
menopausal women with mild to moderate hypertension. e
principal ndings reveal that both short-term intermittent
high-intensity and prolonged moderate-intensity swim train-
ing reduced systolic blood pressure and improved both water
andland-basedexercisecapacities.BecausetheHIgrouponly
covered –% of the total mileage and spent one-third of
time on training compared to the moderate-intensity training
group, high-intensity intermittent training appears to be a
time-ecient alternative to traditional recreational training
regimes in untrained individuals.
e present ndings support that swim training appears
to have a high potential in the treatment of patients with
arterial hypertension, which is supported by others applying
aquatic training protocols [,]. For example, similar
decreases in blood pressure were reported by Tanaka et al.
[] and Nualnim and coworkers [] demonstrated that
 wks of regular swim training lowered SBP by  mmHg in
adults older than  yrs with mild hypertension. In addition,
the swim exercise training also produced a % increase
in carotid artery compliance, as well as improvements in
ow-mediated dilation and cardiovagal baroreex sensitivity
[]. In addition, in a cross-sectional study, middle-aged
swimmers had a lower carotid systolic blood pressure and
carotid pulse pressure than sedentary controls. Moreover,
carotid arterial compliance was higher and 𝛽-stiness index
was reported to be lower in the swimmers in comparison
BioMed Research International
CON MOD HIT
Yo-Yo IE1performance (m)
0
100
200
300
400
500
600
700
800
900
(a)
0wks
15 wks
CON MOD HIT
0
86
88
90
92
94
96
98
100
Submax. Yo-Yo IE1HR (%HRmax)
(b)
F : Yo-Yo Intermittent Endurance level  performance (a) as
well as heart rate aer controlled intermittent submaximal exercise
(%HRmax, (b)) before and aer  wks with thrice-weekly training
sessions of high-intensity swimming (HIT) and moderate-intensity
swimming (MOD) in comparison to an inactive control group
(CON). Data are presented as means ±SEM. denotes signicant
dierence between the training groups and CON.
to the controls []. us, both intermittent high-intensity
and continuousmoderate-intensity swimming can be recom-
mended for adults with mild hypertension.
In some review articles it is suggested that low-to-
moderate-intensity exercise regimes are more ecient than
protocols encompassing high-intensity exercise []. How-
ever, in the present study both training groups’ SBP was
lowered by -%, which conrms ndings in untrained men
in their midthirties performing intense intermittent and con-
tinuous moderate-intensity running []. In the study by Nybo
et al. [], SBP was lowered in both training groups, but only
DBP declined in the continuous moderate-intensity group,
while mean arterial pressure (MAP) declined aer both types
of training. In the present study DBP was unchanged in both
swim training groups, and MAP tended (𝑃 = 0.06)todecline
Endurance swimming performance (s)
0
240
260
280
300
320
340
360
380
400
MOD HIT
(a)
Repeated swimming sprint test (s)
0
90
100
110
120
130
140
150
160
170
180
0wks
15 wks
MOD HIT
#
(b)
F : Endurance swimming performance (a) and repeated
swimming sprint time (b) before and aer  wks with thrice-
weekly training sessions with high-intensity swimming (HIT) and
moderate-intensity swimming (MOD) in comparison to an inactive
control group (CON). Data are presented as means ±SEM.
denotes signicant dierence between the training groups and
CON. # denotes signicant dierences between HIT and MOD.
only in the high-intensity training group with % of the par-
ticipants demonstrating a reduction. us, the discrepancy
between ndings by Nybo et al. []andthepresentstudymay
relate to the dierences in training mode, since exercise in
a supine position may provide a dierent training stimulus
to cardiovascular parameters compared to upright exercise
modes such as running due to the dierences in ventricular
volumes []. Moreover, gender dierences have been shown
to be present within a range of physiological adaptations to
exercise training [,]. Nybo et al. []usedmaleparticipants
and women seem to display smaller reductions in blood
pressure aer exercise training interventions in comparison
to their male counterparts [,,]. In contrast Ishikawa
et al. [] demonstrated that the gender did not inuence
the ecacy of physical activity for lowering elevated blood
pressure.
BioMed Research International
In a recent study by Rocha et al. []isogenicrats
were exposed to swim training at low, moderate, and high
intensities and large morphological alterations in the cardiac
myocytes occurred aer high-intensity training in compar-
ison to low and moderate intensities. ese ndings are in
line with several recent review papers supporting that high-
intensity training markedly reduced arterial blood pressure
[,,]. In addition, supportive of this notion are several
studies on cardiovascular eects of recreational football
training from our laboratory on sedentary men [,,]
and women [,]. us, the rapid acceleration of heart rate
andstrokevolumeduringsquare-wavetransitionsfromlow-
to high-intensity exercise as performed in the high-intensity
traininggroupinthepresentstudymaybeanimportant
stimulus to blood pressure reduction. is suggestion is
backedupbythesimilarresponsesobservedinthetwo
training interventions despite large dierences in training
volume.
In the present study total fat mass was reduced and
lean body mass increased in both training groups. In the
aforementioned study by Nybo et al. [] with untrained
men high-intensity running did not change fat mass or
fat oxidation during submaximal exercise. In contrast, the
moderate-intensity running group displayed a reduction in
fat mass as in the present study. Studies by Tjønna et al.
[,] and Schjerve et al. [] compared “isocaloric” high-
intensity and moderate-intensity training and found major
advantages of the high-intensity training regimes. However,
in these studies the overall energy turnover was matched in
contrast to the present study. erefore, it may be surprising
that the reduction in fat mass was not dierent between the
HIT and MOD interventions despite the large dierence in
total energy turnover. e caloric intake was not controlled
in the present study, which may have aected the body fat
adaptations. For example, it has recently been demonstrated
that appetite regulating variables such as leptin are aected
by high-intensity training []. Additionally, the ndings in
the present study are supported by others showing marked
decreases in body fat content aer high-intensity training
[].
No changes were observed in blood lipid prole in the
present study, which is in contrast to ndings by others
demonstrating that prolonged moderate-intensity running
reduces total/HDL-cholesterol ratio and elevates fat oxidation
during exercise in contrast to brief intense interval training
[]. It is suggested that changes in blood lipid prole relates
to changes in fat mass [], and in the present study no
statistical dierences were evident between the reduction in
body fat between the two interventions, which may partly
explain the similar blood lipid responses. One explanation
for the above-mentioned discrepancy might be that some
of the participants in the present study had normal plasma
cholesterol levels prior to the intervention. If the participants
who had total cholesterol levels lower than . mmolL−1 were
excluded from the statistical analysis, there was a signicant
reduction in total cholesterol in the MOD training group and
a tendency (𝑃 < 0.06)toareductioninHIT(datanotshown),
indicating that women with high plasma cholesterol levels are
more likely to respond to exercise.
e improved performance aer high-intensity as well
as moderate-intensity swimming conducted in the present
studymayberelatedtoanimprovedphysiologicalcapacity,
improved swimming technique, or both. e rather large
% improvement in land-based shuttle-run performance
observed in the two swim-training groups, but not in the
control group, strongly indicates that physiological adapta-
tions are a major contributor for the augmented exercise
capacity observed during both shuttle runs and swim tests.
is is further supported by the % heart rate reduction
observed aer the initial ve 2×20m runs indicating
improved aerobic capacity. Previously, the possible transfer
eect between swim training and land-based activity has
been neglected. is is largely because increases in maximal
oxygen uptake aer swim training appear to be specic for
that exercise modality as observed in monozygotic twins
[] and an observation of unchanged running VO2max,
despite increased swimming VO2max in elite swimmers aer
monthsofintensetraining[,]. However, shuttle-run
performance is not strongly correlated to VO2max [,]
and the current observation suggests that possible benecial
health adaptations obtained aer swim training also translate
into improved land-based exercise capacity. However, it
also appears likely that a technical improvement may have
occurred during the swim training. It can be speculated
that the much higher total distance covered by the MOD
group caused greater technical improvements than in the
HITgroupandthatthisisthereasonforthetendency
to a larger performance gain in the min swim test of
the MOD group. e larger improvement observed for the
HIT than MOD group in repeated sprint swimming ability
could be related to more specic motor learning leading to
larger improvements in sprint technique in this group but
could also be due to metabolic and physiological adaptations
specic to sprinting. For example, high-intensity training is
known to recruit more fast type II muscle bres [,]
which could have yielded greater muscle hypertrophy and
more pronounced enzymatic adaptations in type II bres
for the high-intensity group compared to the moderate-
intensity training group []. Physiological adaptations that
would favor improvements in intense short-duration exercise
performance such as in the interval sprint test may be part of
the explanation for the greater eect on sprint performance in
the high-intensity swimming group ( versus %). However,
these suggestions remain speculative and warrant further
investigation.
In conclusion, high-intensity intermittent swimming is
a time-ecient and eective training method and improves
cardiovascular health and physical performance in sedentary,
premenopausal women with mild hypertension. Adaptations
are similar with high- and moderate-intensity training,
despite less total time spent and distance covered in the high-
intensity group.
Conflict of Interests
e authors declare that there is no conict of interests
regarding the publication of this paper.
BioMed Research International
Acknowledgments
e great eort and positive attitude by the participants
are highly acknowledged. In addition, the technical assis-
tance of Remi Lamhauge, Brynhild Klein, Pauli Øssursson
Mohr, Heini Rasmussen, Olua a Høvdanum, Jakup Mohr,
Ivy Hansen, GunnriðJ´
oannesarson, GuðriðAnd´
orsd´
ottir,
HergerðJoensen, Ann Østerø, Ebba Andreassen, Maud av
Fløtum, Liljan a Fløtum Petersen, Marjun omsen, David
Childs, Sarah Jackman, and Jens Jung Nielsen is greatly
appreciated. e study was supported by a grant from the
Faroese Research Council, e Faroese Confederation of
Sports and Olympic Committee (Itrottarsamband Foroya),
and the Danish Sports Confederation (Danmarks Idrætsfor-
bund). In addition, nancial support was obtained from Eik
Bank.
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... The study was designed as a randomized, controlled trial. Parts of the acquired data have been published previously (Mohr, Nordsborg, et al., 2014;Nordsborg et al., 2015;Sjúrðarson et al., 2024), including detailed analyses of blood pressure and resting heart rate measurements, as reported by . Participants were randomly allocated into either (1) a high-intensity intermittent swimming group (HIS, n = 21), (2) a moderate-intensity continuous swimming group (MOD, n = 21) or (3) a control group (CON, n = 20) (Table 1). ...
... The mean arterial pressure (MAP) was calculated using the formula: MAP = (SBP/3) + (2 × DBP/3). However, the results from the blood pressure measurement have been reported elsewhere (Mohr, Nordsborg, et al., 2014). ...
... We acknowledge the importance of considering intervention-induced changes in blood pressure, given that our study population comprised hypertensive women, and arterial hypertension can independently modify cardiac structure and function. While the present manuscript does not include blood pressure measurements, these data have been published previously (Mohr, Nordsborg, et al., 2014). As reported in , systolic blood pressure decreased following 15 weeks of both HIS by 6 mmHg (~4%) and MOD by 4 mmHg (~3%), with no statistical difference between the two groups. ...
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This study aimed to investigate the impact of swim training intensity and duration on cardiac structure and function in mildly hypertensive women. Sixty‐two mildly hypertensive women were randomized to 15 weeks of either (1) high‐intensity swimming (HIS, n = 21), (2) moderate‐intensity swimming (MOD, n = 21) or (3) control (CON, n = 20). Training sessions occurred three times per week. Cardiac measurements were conducted using echocardiography pre‐ and post‐intervention. Both the HIS and MOD groups demonstrated significant within‐group increases in left ventricular mass: 7.3% [1.2; 13.2] (p = 0.02) for HIS and 6.2% [0.5; 11.8] (p = 0.03) for MOD. The MOD group also demonstrated a significant increase in left ventricular internal dimension at end‐diastole by 2.4% [0.2; 4.6] (p = 0.03). Post‐hoc analysis of diastolic function markers revealed reduced mitral valve A velocity in both HIS (−14% [−25; −3], p = 0.02) and MOD (−13% [−23; −3], p = 0.01), leading to increased mitral valve E/A ratios of 27% [10; 47] (p = 0.003) and 22% [5; 40] (p = 0.01), respectively. Additionally, only MOD demonstrated increased left atrial diameter of 4.9% [0.7; 9.1] (p =0.02). A significant time×group effect (p = 0.02) existed for global longitudinal strain, which increased by 1.6% [0.2; 3.0] (p = 0.03) in MOD only. In conclusion, swim training for 15 weeks increased left ventricular mass and improved markers of diastolic function in mildly hypertensive women. These independent of exercise intensity and duration in mildly hypertensive women.
... Only four studies using direct measures of exercise capacity as an outcome have been identified in these reviews, including participants with chronic conditions-that is, dyslipidaemia, 43 mild knee osteoarthritis, 44 obese with polycystic ovary syndrome 45 and mild hypertension. 46 An evaluation of AHIIT on improving exercise capacity for people with a broader range of chronic conditions, compared with LBHIIT or other types of aquatic exercise, is needed. ...
... Eighteen trials were included in the systematic review and 16 were eligible for meta-analysis. One study 60 and parts of another study 46 were not included in the meta-analysis owing to a lack of available outcome data. ...
... A number of trials (39%) evaluated the effect of AHIIT versus a non-intervention control group, 43- 45 61 67 69 73 four trials (22%) evaluated the effect of AHIIT versus LBHIIT, 60 62 66 72 four trials evaluated AHIIT versus AMICT, 63-65 71 and three trials were three armed and evaluated AHIIT versus LBHIIT and control, 68 AHIIT versus aquatic resistance and aerobic combination training and a control group, 70 and AHIIT versus aquatic moderate intensity exercise and a control group. 46 The target training intensity profiles were matched in all LBHIIT and AHIIT studies 60 62 66 72 and were increased in a similar way for LBHIIT and AHIIT during the exercise programme. Further detailed descriptions are given in online supplemental file 3. ...
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Objective To investigate the effect of aquatic high-intensity interval training (AHIIT) on exercise capacity in people with chronic conditions. Design Systematic review and meta-analysis. Participants Adults (age ≥18 years) with any chronic conditions (long duration, continuing health problems). Data sources The databases Medline, EMBASE, CINAHL, SPORTSDiscus, PEDro and The Cochrane Library were searched from inception to 11 August 2023. Eligibility criteria Randomised or non-randomised controlled trials of adults reporting one or more chronic conditions were included, comparing the effect of AHIIT with a non-exercising control group, land-based high-intensity interval training (LBHIIT) or aquatic moderate-intensity continuous training (AMICT). Results Eighteen trials with 868 participants with chronic musculoskeletal, respiratory, cardiovascular, metabolic or neurological conditions were included. Adherence to AHIIT was high, ranging from 84% to 100%. There was moderate certainty in evidence according to the Grading of Recommendations Assessment, Development and Evaluation system for a moderate beneficial effect on exercise capacity standardised mean differences (SMD) 0.78 (95% CI 0.48 to 1.08), p<0.00001) of AHIIT compared with a non-exercising control group. There was moderate certainty in evidence for no difference of effects on exercise capacity (SMD 0.28 (95% CI −0.04 to 0.60), p=0.08) of AHIIT compared with LBHIIT. There was moderate certainty in evidence for small effect on exercise capacity (SMD 0.45 (95% CI 0.10 to 0.80), p=0.01) of AHIIT compared with AMICT. Conclusion There are beneficial effects of AHIIT on exercise capacity in people with a range of chronic conditions. AHIIT has similar effects on exercise capacity as LBHIIT and may represent an alternative for people unable to perform LBHIIT. PROSPERO registration number CRD42022289001.
... While reviewing seven different studies, the cardiorespiratory uses of HIIT for hypertensive patients were evaluated. HIIT can improve carotid artery compliance up to 21%, baroreflex sensitivity (12), the rate of oxygen usage by the body while exercising and blood pressure in hypertensive patients (9). Furthermore, HIIT can decrease MSNA levels (14), improve endothelial function and may help in angiogenesis by improving NO and VEGF levels (15). ...
... Although HIIT has a beneficial effect of decreasing cardiovascular risk, more research is suggested for more effective benefits. Most of the research studies consisted of training for less than 3 months (9,10,12,15). Although the studies showed a positive health effect on patients, the long term benefits of HIIT on hypertensive patients are still unknown. ...
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Hypertension is one of the most common primary cardiometabolic diseases and is a major contributor to cardiac mortality and morbidity. Furthermore, cardiac risk factors such as obesity and sedentary lifestyle are often seen in hypertensive patients. Regular exercise acts against these risk factors and improves the overall health of an individual. High-intensity interval training appears to do so in a more efficient way. We used a systematic literature review (SLR) approach to provide an overview of the present literature highlighting the cardiovascular advantages of HIIT in hypertensive individuals. We reviewed 4004 articles from reputable journals published between 2013 and August 14, 2023, focusing on 7 selected papers for in-depth analysis. This systematic review revealed the protective effects of HIIT against cardiac complications in hypertension. All the reviewed articles showed a decrease in blood pressure and many other risk variables of cardiovascular diseases. However, guidelines for this exercise are needed for maximum benefits. Therefore, further research on HIIT is necessary to fully harness its potential.
... FS can primarily enhance cardiovascular endurance and aerobic capacity. Studies establish that regular FS can significantly improve cardiovascular health by increasing heart rate, promoting efficient oxygen utilization, and enhancing overall aerobic fitness 24,25 . In contrast, ART involves specific exercises performed against the resistance of water, targeting strength and muscle mass 26 . ...
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The aim of this study was to examine the effects of free swimming (FS), aquatic resistance training (ART), and their combination (FS&ART) on the body composition, blood pressure, and physical fitness of older adults. The study employed a randomized controlled design, comparing three experimental groups with a control group. Eighty volunteers aged between sixty and seventy years (age: 66.2 ± 2.3 years; body mass index: 25.8 ± 4.3 kg/m²) participated in the 16-week intervention, consisting of two weekly sessions. Assessments were conducted at baseline and post-intervention, including anthropometric measurements, blood pressure readings, and the Senior Fitness Test. Significant differences were found between groups in post-intervention considering the chair stand test (p = 0.017; ES = 0.125), arm curl test (p = 0.029; ES = 0.111), 8-foot up and go test (p = 0.042; ES = 0.102), and walk test − 6 min (p = 0.005; ES = 0.156). Specifically, both ART (+ 20.1%; p < 0.05) and FS&ART (+ 19.5%; p < 0.05) showed significantly greater improvements in the chair stand test compared to the control group. Similarly, ART (+ 23.1%; p < 0.05) and FS&ART (+ 18.7%; p < 0.05) performed better than the control group. FS&ART also exhibited a significant improvement over the control group in the 8-foot up-and-go test (+ 14.6%; p < 0.05). In the 6-minute walk test, FS (+ 19.4%; p < 0.05) and FS&ART (+ 15.9%; p < 0.05) both significantly outperformed the control group. This study found that FS improves cardiovascular endurance, while ART enhances muscular strength and endurance in older adults, with combined benefits for agility, suggesting integration of combined modalities into community wellness initiatives for enhanced physical fitness and health outcomes.
... A review in 2023 underlines the importance of non-pharmaceutical intervention for HTA represented by hydrotherapy, balneotherapy and spa therapy [22]. In the last 10 years, more and more articles have referred to swimming as a healthy possibility to prevent heart diseases and even improve cardiovascular health and HTA rates [23][24][25][26][27][28][29]. ...
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Hypertension is among the top risk factors for cardiovascular diseases. Diversified rehabilitation programs are needed to limit the progression of the high blood pressure condition. The welfare of aquatic therapy is acknowledged, but hydrotherapeutic procedures are rarely used in cardiovascular diseases. The study aims to assess the impact of an exhaustive hydro-kinetic thermo therapeutic program compared to other methods of treatment, i.e., cardiovascular rehabilitation program, recommendation for a healthy life, and antihypertensive medication. Four groups of patients (46 years ±0,32) diagnosed with hypertension participated in four different rehabilitation programs to analyze the impact on their effort capacity. Their ability to achieve average effort without the appearance of fatigue symptoms was studied for a period of eight weeks by monitoring six parameters: systolic blood pressure (SBP), diastolic blood pressure (DBP), Borg Scale, Medical Research Council Dyspnoea Scale (MRC-DS), pulse (P) and oxygen saturation (O2). Group A, which benefited only of recommendations for a healthy life, didn’t register any significant p values between the initial and final evaluation; group B, which had medications and recommendations for a healthy life, registered significant p values for 2 parameters (SBP and P have p<0.0001); group C, which took part in a cardiovascular rehabilitation program, obtained significant p values for 5 parameters (SBP, DBP, Borg, MRC-DS and O2 have p<0.0001); Group D, the recipient of hydrotherapeutic program, registered significant p values for all statistically 6 monitored parameters (SBP, DBP, Borg, MRC-DS, P and O2 have p<0.0001). Physical activity in water performed regularly within a controlled therapeutic program with the thermal and electrotherapy components, leading to improved capacity for the effort by decreasing blood pressure values and dyspnea parameters.
... Regarding the effect of the Sp-HIIT and Sp-MICT interventions on body composition, this study demonstrated significantly favourable effects on body weight and fat percentage. No significant differences were observed between training interventions, which confirms other findings in untrained hypertensive women [49], but contrasts findings in sedentary males [15]. However, none of these studies controlled for altered nutritional habits, which is a limitation. ...
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This study aims to investigate the effects of self-paced high-intensity interval training (Sp-HIIT) vs. self-paced moderate-intensity continuous training (Sp-MICT) on aerobic fitness levels, psychophysiological responses, and antioxidant status to assess the relationship between aerobic fitness levels and antioxidant markers. Physically active young adults were randomised into Sp-HIIT and Sp-MICT groups. The intervention consisted of three weekly sessions during an eight-week period. Sp-HIIT consisted of performing two sets of 12-24 × 30 s high-intensity runs ≥ 85% HR max followed by 30 s rest periods, while Sp-MICT consisted of performing 24-48 min of continuous running at 60-75% HR max. Pre-and post-intervention testing included a maximal oxygen uptake (VO 2max) assessment during a 30-15 intermittent fitness test (30-15 IFT), as well as resting blood samples, which were analysed for oxidative stress markers (malondialdehyde (MDA)) and activity of intracellular antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD) and reduced (GSH) and oxidized glutathione (GSSG)). The Sp-HIIT group showed a greater improvement in velocity of 30-15 IFT, VO 2max , and MDA responses. Furthermore, the Sp-HIIT group demonstrated higher psychophysiological responses than the Sp-MICT group, except for anger responses. In conclusion, these results suggest that Sp-HIIT has a higher level of beneficial exercise-induced effects in physiological responses with greater perceived exertion in physically active young adults.
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Background Several reviews have examined the health benefits of participation in specific sports, such as baseball, cricket, cross-country skiing, cycling, downhill skiing, football, golf, judo, rugby, running and swimming. However, new primary studies on the topic have recently been published, and the respective meta-analytic evidence needs to be updated. Objectives To systematically review, summarise and appraise evidence on physical health benefits of participation in different recreational sports. Methods Searches for journal articles were conducted in PubMed/MEDLINE, Scopus, SpoLit, SPORTDiscus, Sports Medicine & Education Index and Web of Science. We included longitudinal and intervention studies investigating physical health outcomes associated with participation in a given sport among generally healthy adults without disability. Results A total of 136 papers from 76 studies conducted among 2.6 million participants were included in the review. Our meta-analyses of available evidence found that: (1) cycling reduces the risk of coronary heart disease by 16% (pooled hazard ratio [HR] = 0.84; 95% confidence interval [CI]: 0.80, 0.89), all-cause mortality by 21% (HR = 0.79; 95% CI: 0.73, 0.84), cancer mortality by 10% (HR = 0.90; 95% CI: 0.85, 0.96) and cardiovascular mortality by 20% (HR = 0.80; 95% CI: 0.74, 0.86); (2) football has favourable effects on body composition, blood lipids, fasting blood glucose, blood pressure, cardiovascular function at rest, cardiorespiratory fitness and bone strength (p < 0.050); (3) handball has favourable effects on body composition and cardiorespiratory fitness (p < 0.050); (4) running reduces the risk of all-cause mortality by 23% (HR = 0.77; 95% CI: 0.70, 0.85), cancer mortality by 20% (HR = 0.80; 95% CI: 0.72, 0.89) and cardiovascular mortality by 27% (HR = 0.73; 95% CI: 0.57, 0.94) and improves body composition, cardiovascular function at rest and cardiorespiratory fitness (p < 0.010); and (5) swimming reduces the risk of all-cause mortality by 24% (HR = 0.76; 95% CI: 0.63, 0.92) and improves body composition and blood lipids (p < 0.010). Conclusions A range of physical health benefits are associated with participation in recreational cycling, football, handball, running and swimming. More studies are needed to enable meta-analyses of health benefits of participation in other sports. PROSPERO registration number CRD42021234839.
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This study aims to investigate the effects of self-paced high-intensity interval training (Sp-HIIT) vs self-paced moderate-intensity continuous training (Sp-MICT) on the aerobic fitness level, psy-chophysiological responses and antioxidant status, to assess the relationship between aerobic fit-ness level and antioxidant markers. Well-trained males were randomised into Sp-HIIT and Sp-MICT. The intervention consisted of 3 weekly sessions during an 8-wk period. Sp-HIIT per-formed two sets of 12–24 x 30-s high-intensity runs ≥85 %HRmax followed by 30-s rest periods, while Sp-MICT performed 24-48 min of continuous running at 60-75 %HRmax. Pre and post-intervention testing included maximal oxygen uptake (VO2max) assessment during a 30-15 intermittent fitness test (30-15 IFT), as well as resting blood samples analysed for oxidative stress markers (Malondialdehyde (MDA)) and intracellular antioxidant enzymes activity (Catalase (CAT), Superoxide Dismutase (SOD) and Reduced (GSH) and Oxidized Glutathione (GSSG)). The Sp-HIIT showed meaningfully greater improvement in velocity of 30-15 IFT, VO2max and MDA responses. Furthermore, the Sp-HIIT demonstrated higher psychophysiological responses than the Sp-MICT, except for anger responses. In conclusion, these results suggest that Sp-HIIT has higher level of exercise-induced beneficial effects in physiological responses with greater perceived exer-tion in young well-trained adults.
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In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation. Primary recommendation: To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)]
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Swimming is an exercise modality that is highly suitable for health promotion and disease prevention, and is one of the most popular, most practiced and most recommended forms of physical activity. Yet little information is available concerning the influence of regular swimming on coronary heart disease (CHD). Exercise recommendations involving swimming have been generated primarily from unjustified extrapolation of the data from other modes of exercise (e.g. walking and cycling). Available evidence indicates that, similarly to other physically active adults, the CHD risk profile is more favourable in swimmers than in sedentary counterparts and that swim training results in the lowering of some CHD risk factors. However, the beneficial impact of regular swimming may be smaller than land-based exercises. In some cases, regular swimming does not appear to confer beneficial effects on some CHD risk factors. Moreover, swimming has not been associated with the reduced risks of developing CHD. Thus, extrapolation of research findings using land-based exercises into swimming cannot be justified, based on the available research. Clearly, more research is required to properly assess the effects of regular swimming on CHD risks in humans.
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Growing research suggests that high-intensity interval training (HIIT) is a time-efficient exercise strategy to improve cardiorespiratory and metabolic health. "All out" HIIT models such as Wingate-type exercise are particularly effective, but this type of training may not be safe, tolerable or practical for many individuals. Recent studies, however, have revealed the potential for other models of HIIT, which may be more feasible but are still time-efficient, to stimulate adaptations similar to more demanding low-volume HIIT models and high-volume endurance-type training. As little as 3 HIIT sessions per week, involving ≤10 min of intense exercise within a time commitment of ≤30 min per session, including warm-up, recovery between intervals and cool down, has been shown to improve aerobic capacity, skeletal muscle oxidative capacity, exercise tolerance and markers of disease risk after only a few weeks in both healthy individuals and people with cardiometabolic disorders. Additional research is warranted, as studies conducted have been relatively short-term, with a limited number of measurements performed on small groups of subjects. However, given that "lack of time" remains one of the most commonly cited barriers to regular exercise participation, low-volume HIIT is a time-efficient exercise strategy that warrants consideration by health practitioners and fitness professionals.
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The current exercise prescription for the treatment of hypertension is: cardiovascular mode, for 20–60 minutes, 3–5 days per week, at 40–70% of maximum oxygen uptake (V̇O2max). Cardiovascular exercise training is the most effective mode of exercise in the prevention and treatment of hypertension. Resistance exercise is not the preferred mode of exercise treatment, but can be incorporated into an exercise regime provided the diastolic blood pressure response is within safe limits. It is inconclusive whether durations longer than 30 minutes produce significantly greater reductions in blood pressure. A frequency of three exercise sessions per week has been considered to be the minimal frequency for blood pressure reduction. Higher frequencies tended to produce greater reductions, although not significantly different. Evidence still exists that high intensity exercise (>75% V̇O2max) may not be as effective as low intensity exercise (
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The present study examined the effects of short-term recreational football training on blood pressure (BP), fat mass, and fitness in sedentary, 35-50-year-old premenopausal women with mild hypertension. Forty-one untrained, hypertensive women were randomized into a football training group (n = 21; FTG) and a control group (n = 20; CON). FTG performed 45 ± 1 1-h small-sided football training sessions during the 15-week intervention period. BP, body composition (dual-energy x-ray absorptiometry), blood lipid profile, and fitness level were determined pre- and post-intervention. After 15 weeks, systolic and diastolic BP, respectively, were lowered more (P < 0.05) in FTG (-12 ± 3 and -6 ± 2 mmHg) than in CON (-1 ± 1 and 1 ± 2 mmHg). Total body fat mass decreased more (P < 0.05) in FTG than in CON during the 15-week intervention period (-2.3 ± 0.5 kg vs 0.4 ± 0.3 kg). After 15 weeks, both total cholesterol (-0.4 ± 0.1 mmol/L vs 0.1 ± 0.2 mmol/L) and triglyceride (-0.2 ± 0.1 mmol/L vs 0.3 ± 0.2 mmol/L) were lowered more (P < 0.05) in FTG than in CON. Yo-Yo intermittent endurance level 1 test performance increased more (P < 0.05) in FTG than in CON (111 ± 18% vs 1 ± 3%) during the 15-week intervention period. In conclusion, short-term football training resulted in a marked reduction in BP and induced multiple improvements in fitness and cardiovascular health profile of untrained, premenopausal women with mild hypertension.