This was a longitudinal prospective pilot study including CF children aged
between 6 and 15 years and attending the pediatric CF center of the Brussels
Free University, Belgium. The patients were included during a period of 2 months
on the occasion of their follow-up visit. The patients with a medical
contraindication to practice a sport, including hypoxemia, post-pneumothorax
status severe, hemoptysis, or osteoarticular abnormalities, were excluded from
participation. The study was integrated into the regular patient follow-up,
scheduled to take place every 6 weeks, which included 3 follow-up visits. The
first consisted of a routine visit to explain the project. Following the signing
of patient or parental informed consent forms, the second visit was performed at
starting the practice of sport (T0), and the third took place
at month 6. The body mass index (BMI) and spirometric values, including forced
expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and 25% to
75% forced expiratory flow (FEF) were collected, along with the duration of
extracurricular PA (hours/week). Data were expressed as
z-scores based on GLI-2012 reference.10 (link) An incremental shuttle
test (IST) was performed at T0 and month 6 in order to assess
maximum oxygen uptake (VO2max). A variety of tests was applied to evaluate the
children’s physical status. Cardiopulmonary exercise testing (CPET) is
considered the gold standard, yet it requires expensive equipment and
specialized personnel.3 (link),11 (link) Therefore, IST may be a good alternative, given that it is
simple, inexpensive, and reliable.6 (link),12 (link) In this study, we
performed a 15 m IST, conducted in an enclosed corridor on a flat 15 m-long
course. Patients were instructed to run around 2 cones following the rhythm
dictated by the audio signal. Subjects had to run at the prompting of a sound at
regular intervals, to reach the next pole before the next sound goes on. The
15 m IST has 17 levels. Each level includes an increasing number of shuttles and
the speed therefore increases as the level advances. The 15 m test begins with a
running speed above 7.71 km/hour at Level 1 and ends with a speed of 12 km/hour
at Level 17. The end of the test is determined by the patient, when he/she
becomes unable to maintain the required speed, or by the experimenter if the
patient fails to complete a shuttle during the time allowed. Different
parameters (oxygen saturation, heart rate, and respiratory rate) are documented
before, just after, and 3 minutes later the beginning of the test. This test
evaluates aerobic fitness in a maximal effort. A correlation between the test
performance and VO2max can be extrapolated and permits to evaluate the
cardiorespiratory status of the patients. We estimated the VO2max using the
Matsuzaka equation13 (link):
patients were classified into 2 groups depending on the PA increases: a first
group without change (PA−) and second group with a minimum increase of
1 hour/week (PA+).
between 6 and 15 years and attending the pediatric CF center of the Brussels
Free University, Belgium. The patients were included during a period of 2 months
on the occasion of their follow-up visit. The patients with a medical
contraindication to practice a sport, including hypoxemia, post-pneumothorax
status severe, hemoptysis, or osteoarticular abnormalities, were excluded from
participation. The study was integrated into the regular patient follow-up,
scheduled to take place every 6 weeks, which included 3 follow-up visits. The
first consisted of a routine visit to explain the project. Following the signing
of patient or parental informed consent forms, the second visit was performed at
starting the practice of sport (T0), and the third took place
at month 6. The body mass index (BMI) and spirometric values, including forced
expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and 25% to
75% forced expiratory flow (FEF) were collected, along with the duration of
extracurricular PA (hours/week). Data were expressed as
z-scores based on GLI-2012 reference.10 (link) An incremental shuttle
test (IST) was performed at T0 and month 6 in order to assess
maximum oxygen uptake (VO2max). A variety of tests was applied to evaluate the
children’s physical status. Cardiopulmonary exercise testing (CPET) is
considered the gold standard, yet it requires expensive equipment and
specialized personnel.3 (link),11 (link) Therefore, IST may be a good alternative, given that it is
simple, inexpensive, and reliable.6 (link),12 (link) In this study, we
performed a 15 m IST, conducted in an enclosed corridor on a flat 15 m-long
course. Patients were instructed to run around 2 cones following the rhythm
dictated by the audio signal. Subjects had to run at the prompting of a sound at
regular intervals, to reach the next pole before the next sound goes on. The
15 m IST has 17 levels. Each level includes an increasing number of shuttles and
the speed therefore increases as the level advances. The 15 m test begins with a
running speed above 7.71 km/hour at Level 1 and ends with a speed of 12 km/hour
at Level 17. The end of the test is determined by the patient, when he/she
becomes unable to maintain the required speed, or by the experimenter if the
patient fails to complete a shuttle during the time allowed. Different
parameters (oxygen saturation, heart rate, and respiratory rate) are documented
before, just after, and 3 minutes later the beginning of the test. This test
evaluates aerobic fitness in a maximal effort. A correlation between the test
performance and VO2max can be extrapolated and permits to evaluate the
cardiorespiratory status of the patients. We estimated the VO2max using the
Matsuzaka equation13 (link):
VO2max
(mL/minutes/kg) = (25.9 − 2.21 × G) − 0.0449 × A − 0.831 × Y + 4.12 × MS;
G = 0 for boys and G = 1 for girls; A = age in years; Y = BMI; and
MS = maximum speed.
patients were classified into 2 groups depending on the PA increases: a first
group without change (PA−) and second group with a minimum increase of
1 hour/week (PA+).
