Sports Medicine
Communication
Biosci. Biotech. Res. Comm. 10(4): 810-813 (2017)
Inspiratory muscle strength in well-trained male
Iranian soccer players: A pilot study
Shahram Mohaghegh
Department of Sports and Exercise Medicine, Clinical Research Development Center of Loghman Hakim
Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
ABSTRACT
Maximal inspiratory mouth pressure (MIP) is a common measurement of inspiratory muscle strength, which is often
used in a variety of exercises for estimation of the inspiratory muscle strength and to evaluate the effects of inspira-
tory muscle training. An understanding of elite athletes’ MIP characteristics is necessary to guide sport-speci c
inspiratory muscle training programs. The purpose of this pilot study was to investigate and better understand the
MIP characteristics of well –trained Iranian male soccer players. In a cross -sectional study, from 14 well trained 19
and 20-year old Iranian male soccer players, weight, height, maximal inspiratory muscle pressure (MIP) and peak
inspiratory ow (PIF) were measured. All subjects did not smoke, had at least 3 years competitive experience at club
or provincial level, trained at least four times a week during the competitive season, and engage in tness sessions
(e.g. gymnasium training, jogging, cross-training) at least twice a week. Maximal respiratory pressures were meas-
ured by having the subject expire completely and then perform a maximum inspiratory maneuver through mouth
while the nostrils were closed (Mueller maneuver). Three measurements were done and the best score was recorded.
Mean and Standard deviations of weight, height, MIP and PIF were 73.6(6.6) kg, 179.5(6.7) cm, 99.21(32.34) cmH2O
and 5.57(1.46) lit/s respectively. There have not been reported any national MIP values for healthy Iranian men to
compare the measured ones with them. The MIP measured values were within predicted limits for healthy men based
on anthropometric data. MIP values were signi cantly lower than those found in international studies for elite male
athletes. There is necessary to conduct further researches with larger sample sizes in different sports and also in
healthy sedentary Iranian people to estimate the inspiratory muscle strength in a variety of Iranian athletes.
KEY WORDS: RESPIRATORY MUSCLE; PULMONARY FUNCTION; MAXIMAL INSPIRATORY PRESSURE (MIP); INSPIRATORY MUSCLE TRAINING;
EXERCISE/PHYSIOLOGY
810
ARTICLE INFORMATION:
*Corresponding Author: sh.mohaghegh@sbmu.ac.ir
Received 21
st
April, 2017
Accepted after revision 29
th
Sep, 2017
BBRC Print ISSN: 0974-6455
Online ISSN: 2321-4007 CODEN: USA BBRCBA
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© A Society of Science and Nature Publication, 2017. All rights
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Online Contents Available at: http//www.bbrc.in/
DOI: 10.21786/bbrc/10.4/30
Shahram Mohaghegh
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS INSPIRATORY MUSCLE STRENGTH IN WELL-TRAINED MALE IRANIAN SOCCER PLAYERS 811
INTRODUCTION
Maximal inspiratory mouth pressure (MIP) is a common
measurement of inspiratory muscle strength, which is
often used in a variety of exercises for estimation of the
inspiratory muscle strength and to evaluate the effects of
inspiratory muscle training , (Klusiewicz 2008). Inspira-
tory muscle training is classi ed into two major catego-
ries: inspiratory muscle strength training and inspiratory
muscle endurance training. Inspiratory muscle strength
training is performed by breathing against an external
inspiratory load. This load is often adjusted with refer-
ence to MIP. Inspiratory muscle training requires par-
ticipants to achieve a threshold pressure to open the
valve of an inspiratory muscle training device (e.g., the
POWER breathe inspiratory muscle trainer) to provide an
in ow of air. Substantial respiratory strength is needed
to achieve and maintain the target threshold pressure,
which ranged between 50 and 80% of MIP in different
studies, (HajGhanbari, Yamabayashi et al. 2013).
An understanding of elite athletes’ MIP character-
istics is necessary to guide sport-speci c inspiratory
muscle training programs , (Ohya, Hagiwara et al. 2016).
The characteristics of MIP have already been reported in
both young, (Leech, Ghezzo et al. 1983), and older adults
(Summerhill, Angov et al. 2007). To our knowledge, no
study has quanti ed and reported the MIPs of elite Ira-
nian athletes across a variety of sports. An understand-
ing of the characteristics of elite athletes’ MIPs is needed
to guide inspiratory muscle training programs relative
to speci c sports. The purpose of this pilot study was to
investigate and better understand the MIP characteris-
tics of well –trained Iranian male soccer players.
MATERIAL AND METHODS
In a cross -sectional study, from 14 well trained 19 and
20-year old Iranian male soccer players, weight, height,
maximal inspiratory muscle pressure (MIP) and peak
inspiratory ow (PIF) were measured in summer 2014.
All subjects did not smoke, had at least 3 years com-
petitive experience at club or provincial level, trained
at least four times a week during the competitive sea-
son, and engage in tness sessions (e.g. gymnasium
training, jogging, cross-training) at least twice a week.
After obtaining written consent, proper device calibra-
tion and instruction to participants according to the
manual of the device and getting their consent, maxi-
mal respiratory pressures were measured by having the
subject expire completely and then perform a maximum
inspiratory maneuver through mouth while the nostrils
were closed (Mueller maneuver). Three measurements
were done and the best score was recorded. The meas-
urements were done by an experienced technician using
POWER breathe inspiratory muscle trainer (KH1 pressure
threshold device).The predicted MIP was measured based
on anthropometric data of athletes using this equation:
MIP = (0.158 BMI)-(0.051 age) + 8.22 , (Hautmann, Hefele
et al. 2000). The mean obtained MIP was compared to
mean MIP of some
male athletes in different sports from
different countries using ANOVA test. P value less than
0.05 was considered signi cant.
RESULTS AND DISCUSSION
Mean and Standard deviations of weight, height, MIP
and PIF were 73.6(6.6) kg, 179.5(6.7) cm, 99.21(32.34)
cmH2O and 5.57(1.46) lit/s respectively. The MIP meas-
ured values were within predicted limits for healthy men
based on anthropometric data6. MIP values were sig-
ni cantly lower than those found in most international
studies for elite and non-elite male athletes, (Table 1).
Maximal inspiratory pressure (MIP) is a reliable,
noninvasive factor for assessing the respiratory mus-
cle function, (Tudorache, Oancea et al. 2010). Recently
peak inspiratory ow (PIF) measurement has been of
interest as a reliable and accessible tool for assessment
of respiratory muscle strength in older adults, (Barnes,
Agyapong-Badu et al. 2014).
Maximal inspiratory pressure (MIP) is the most com-
monly used measure for assessment of inspiratory mus-
cle function. Subjective factors which may in uence
MIP include proper test performance, weight, age, sex,
height, tness level and smoking status (Sclauser Pessoa,
Franco Parreira et al. 2014) and (Harik-Khan, Wise et al.
1998). There is no agreement regarding which of these
variables have a signi cant in uence on MIP, (Soori,
Mohaghegh et al. 2016).
In this study, Mean and Standard deviations of
weight, height, MIP and PIF were 73.6(6.6) kg, 179.5(6.7)
cm, 99.21(32.34) cmH2O and 5.57(1.46) lit/s respec-
tively. There have not been reported any national MIP
values for healthy Iranian men to compare the measured
ones with them. MIP values were signi cantly lower
than those found in most international studies for male
athletes, (Table 1) (Santos, Rosa et al. 2012) and (Ohya,
Hagiwara et al. 2016). This may be the result of differ-
ences in measurements of MIP, or anthropometric vari-
ations in these studies or sports-speci c differences in
inspiratory muscle strength or real weaker inspiratory
muscles in Iranian athletes; although it is too early for
this conclusion as the number of participants in this
study was low. The MIP values of some athletes in spe-
ci c sports such as swimming and rowing tended to be
stronger (table 1). It has been mentioned that athletes
whose sport typically demands exercise-induced inspir-
atory muscle fatigue tend to have stronger MIP values
than other athletes, (Ohya, Hagiwara et al. 2016).
Shahram Mohaghegh
812 INSPIRATORY MUSCLE STRENGTH IN WELL-TRAINED MALE IRANIAN SOCCER PLAYERS BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Inspiratory muscle fatigue (IMF) occurs after swim-
ming, short-duration high-intensity exercise, and long-
duration exercise. In swimming, it is required to exactly
harmonize the frequency of breathing and tidal volume
with stroke mechanics, which causes a different breath-
ing pattern compared with on-land exercise. Also, pos-
sible effect of body position on breathing and increased
hydrostatic pressure on the chest during swimming
result in an increased load on the respiratory system. In
running, IMF occurred after a 400-m and 800-mrunning
test and additional work from the inspiratory muscles is
required, (Ohya, Hagiwara et al. 2016). The relationship
between the MIP values and the sport type has to be
determined and further researches are warranted.
CONCLUSION
There is necessary to conduct further researches with
larger sample sizes in different sports and also in healthy
sedentary Iranian people to estimate the inspiratory
muscle strength in a variety of Iranian athletes.
ACKNOWLEDGMENTS
Thanks to Professor Latif Gachkar for his help in sta-
tistical analysis of the data, to Dr Hassan Moghimi and
Pneuma Center Corporation for providing the device for
measuring MIP and PI.
FINANCIAL DISCLOSURE
We have no nancial interests related to the material in
the manuscript.
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Table 1. Mean values of the maximal inspiratory pressure (MIP) in male athletes from various sports (comparison of the
published data)
Author Subjects Age Number MIP (cmH
2
O)
Signi cant difference
with present data
(p value less than 0.05)
(McConnell, Caine et al. 1997).
Moderately- trained
individuals
23±2.8 24 158±29 Yes
(Fuso, Di Cosmo et al. 1996). Elite soccer players 23±3 27 114±32 Yes
(Romer, McConnell et al. 2002). Cyclists and triathletes 29.5±3.3 E
30.3±2.6 C
16
102±6 E
100±6 C
No
(Klusiewicz 2008). Elite rowers 24.8±3.2 15 157±23 Yes
(Klusiewicz 2008).
Representatives of endurance
sports
17-34 35 143±25 Yes
(Ohya, Hagiwara et al. 2016). Elite basketball players 22.9 ± 2.0 14 126.1 Yes
(Ohya, Hagiwara et al. 2016). Elite swimmers 22.1 ± 2.0 12 166.1 Yes
E – Experimental group, C – Control group
Shahram Mohaghegh
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS INSPIRATORY MUSCLE STRENGTH IN WELL-TRAINED MALE IRANIAN SOCCER PLAYERS 813
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