Revisión de Expand-a-Lung: Efectos en VO2Max, Ejercicio y oxígeno corporal

J Spinal Cord Med. 2008;31(1):65-71.
Effects of respiratory resistance training with a concurrent flow device on
wheelchair athletes.
Litchke LG, Russian CJ, Lloyd LK, Schmidt EA, Price L, Walker JL.
The Human Performance Laboratory, Department of Health, Physical Education, and
Recreation, Texas State University-San Marcos, San Marcos, Texas 78666, USA.
BACKGROUND/OBJECTIVE: To determine the effect of respiratory resistance
training (RRT) with a concurrent flow respiratory (CFR) device on
respiratory function and aerobic power in wheelchair athletes.
METHODS: Ten male wheelchair athletes (8 with spinal cord injuries, 1 with a
neurological disorder, and 1 with postpolio syndrome), were matched by
lesion level and/or track rating before random assignment to either a RRT
group (n = 5) or a control group (CON, n = 5). The RRT group performed 1 set
of breathing exercises using Expand-a-Lung, a CFR device, 2 to 3 times daily
for 10 weeks. Pre/posttesting included measurement of maximum voluntary
ventilation (MVV), maximum inspiratory pressure (MIP), and peak oxygen
consumption (V(O2peak)).
RESULTS: Repeated measures ANOVA revealed a significant group difference in
change for MIP from pre- to posttest (P < 0.05). The RRT group improved by
33.0 cm H2O, while the CON group improved by 0.6 cm H2O. Although not
significant, the MW increased for the RRT group and decreased for the CON
group. There was no significant group difference between V(O2peak) for pre/posttesting.
Due to small sample sizes in both groups and violations of some parametric
statistical assumptions, nonparametric tests were also conducted as a
crosscheck of the findings. The results of the nonparametric tests concurred
with the parametric results.
CONCLUSIONS: These data demonstrate that 10 weeks of RRT training with a CFR
device can effectively improve MIP in wheelchair athletes. Further research
and a larger sample size are warranted to further characterize the impact of
Expand-a-Lung on performance and other cardiorespiratory variables in
wheelchair athletes.

Boutellier U, Buchel R, Kundert A, Spengler C.
The respiratory system as an exercise limiting factor in normal trained
subjects.
Department of Physiology, University of Zurich, Switzerland.
Recently, we have shown that an untrained respiratory system does limit the
endurance of submaximal exercise (64% peak oxygen consumption) in normal
sedentary subjects. These subjects were able to increase breathing endurance
by almost 300% and cycle endurance by 50% after isolated respiratory
training. The aim of the present study was to find out if normal, endurance
trained subjects would also benefit from respiratory training. Breathing and
cycle endurance as well as maximal oxygen consumption (VO2max) and anaerobic
threshold were measured in eight subjects. Subsequently, the subjects
trained their respiratory muscles for 4 weeks by breathing 85-160 1 min.-1
for 30 min daily. Otherwise they continued their habitual endurance
training. After respiratory training, the performance tests made at the
beginning of the study were repeated. Respiratory training increased
breathing endurance from 6.1 (SD 1.8) min to about 40 min. Cycle endurance
at the anaerobic threshold [77 (SD 6) %VO2max] was improve from 22.8 (SD
8.3) min to 31.5 (SD 12.6) min while VO2max and the anaerobic threshold
remained essentially the same. Therefore, the endurance of respiratory
muscles can be improved remarkably even in trained subjects. Respiratory
muscle fatigue induced hyperventilation which limited cycle performance at
the anaerobic threshold. After respiratory training, minute ventilation for
a given exercise intensity was reduced and cycle performance at the
anaerobic threshold was prolonged.
In Summary, the condition of the respiratory system is more important for
endurance exercise performance of healthy trained subjects than hitherto
assumed. Not only do respiratory muscles fatigue during intensive endurance
exercise, but prefatigued respiratory muscles can also impair performance.
In turn, respiratory endurance training can improve endurance exercise
performance.

Claes E.G. Lundgren, M.D., PhD., professor of physiology and Biophysics in
the State University of New IMPROVE ENDURANCE AND PERFORMANCE THROUGH RESPIRATORY MUSCLE TRAINING
York, UB School of Medicine. This research was
supported by the US Navy Experimental Diving Unit.
In this pioneering work, subjects who followed breathing resistance training
improved their snorkel surface swimming time by 33% and their underwater
Scuba swimming time by 66%.
“The above data is in agreement with previous studies in cyclist, rowers and
runners. They suggest that athletes in most sports could improve their
performance by undergoing respiratory muscle training. It is also clear that
the greater the stress on the respiratory system , the larger the
improvement in performance.”
During high intensity exercise, when the breathing muscles become fatigued,
the body switches to survival mode and “steals” blood flow and oxygen away
from locomotor muscles. As a result, these locomotor muscles become fatigued
and performance can suffer significantly. Increasing the strength of the
respiratory muscles through breathing resistance exercise can prevent this
fatigue during sustained exercise situations. The end result is better
performance!

F. Lötters, B. van Tol, G. Kwakkel and R. Gosselink
Inspiratory Muscle Training In COPD
Department of Public Health, Faculty of Medicine and Health Sciences, Erasmus
University Rotterdam, Rotterdam, and Department of Physical Therapy and Research
Institute for Fundamental and Clinical Human Movement Sciences, University
Hospital Vrije Universteit, Amsterdam, the Netherlands. Department of
Respiratory Rehabilitation, University Hospitals Leuven, Katholieke
Universiteit, Leuven, Belgium
The purpose of this meta-analysis is to review studies investigating the
efficacy of inspiratory muscle training (IMT) in chronic obstructive
pulmonary disease (COPD) patients and to find out whether patient
characteristics influence the efficacy of IMT.
A systematic literature search was performed using the Medline and Embase
databases. On the basis of a methodological framework, a critical review was
performed and summary effect-sizes were calculated by applying fixed and
random effects models.
Both IMT alone and IMT as adjunct to general exercise reconditioning
significantly increased inspiratory muscle strength and endurance. A
significant effect was found for dyspnoea at rest and during exercise.
Improved functional exercise capacity tended to be an additional effect of
IMT alone and as an adjunct to general exercise reconditioning, but this
trend did not reach statistical significance. No significant correlations
were found for training effects with patient characteristics. However,
subgroup analysis in IMT plus exercise training revealed that patients with
inspiratory muscle weakness improved significantly more compared to patients
without inspiratory muscle weakness.
Conclusions: From this review it is concluded that inspiratory muscle
training is an important addition to a pulmonary rehabilitation programme
directed at chronic obstructive pulmonary disease patients with inspiratory
muscle weakness.

Paltiel Weiner, MD; Rasmi Magadle, MD; Marinella Beckerman, MD; Margalit
Weiner, PhD and Noa Berar-Yanay, MD
Expiratory Muscle Training in COPD
*From the Department of Medicine A, Hillel Yaffe Medical Center, Hadera,
Israel.
Background: There are several reports showing that expiratory muscle
strength and endurance can be impaired in patients with COPD. This muscle
weakness may have clinically relevant implications. Expiratory muscle
training tended to improve cough and to reduce the sensation of respiratory
effort during exercise in patients other than those with COPD.
Methods: Twenty-six patients with COPD (FEV1 38% predicted) were recruited
for the study. The patients were randomized into two groups: group 1, 13
patients were assigned to receive specific expiratory muscle training (SEMT)
daily, six times a week, each session consisting of 1/2 h of training, for 3
months; and group 2, 13 patients were assigned to be a control group and
received training with very low load. Spirometry, respiratory muscle
strength and endurance, 6-min walk test, Mahler baseline dyspnea index
(before), and the transitional dyspnea index (after) were measured before
and after training.
Results: The training-induced changes were significantly greater in the SEMT
group than in the control group for the following variables: expiratory
muscle strength (from 86 ± 4.1 to 104 ± 4.9 cm H2O, p < 0.005; mean
difference from the control group, 24%; 95% confidence interval, 18 to 32%),
expiratory muscle endurance (from 57 ± 2.9% to 76 ± 4.0%, p < 0.001; mean
difference from the control group, 29%; 95% confidence interval, 21 to 39%),
and in the distance walked in 6 min (from 262 ± 38 to 312 ± 47 m, p < 0.05;
mean difference from the control group, 14%; 95% confidence interval, 9 to
20%). There was also a small but not significant increase (from 5.1 ± 0.9 to
5.6 ± 0.7, p = 0.14) in the dyspnea index.
Conclusions: The expiratory muscles can be specifically trained with
improvement of both strength and endurance in patients with COPD.