International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

A STUDY TO COMPARE THE EFFECT OF THRESHOLD INSPIRATORY MUSCLE TRAINER(IMT) DEVICE TRAINING VERSUS CONVENTIONAL TRAINING PROGRAM ON RESPIRATORY MUSCLE STRENGTH IN NON-ELITE HALF MARATHON RUNNERS

*Rajguru Vijayendra and **Momaya Bhakti Pradeep

1. Associate Professor MGM College of Physiotherapy, Kamothe, Navi Mumbai, INDIA. 2. Intern, MGM College of Physiotherapy, Kamothe, Navi Mumbai, INDIA.

Email: [email protected]

(Received September 03, 2018, accepted November 02, 2018)

ABSTRACT

The purpose of this study was to find out effectiveness of threshold device training on respiratory muscles in non-elite half marathon runners. After obtaining ethical clearance and informed consent sixty non-elite half marathon runners in the age group of 35 to 55 years of age participating in Mumbai Marathon and training for at least two consecutive years were randomly selected for the study. Athletes were equally divided into two groups of thirty runners each namely as Group 1-Experimental Group (conventional training and respiratory muscle strength training) and Group 2-Conventional Group (conventional training program) respectively for a period of six weeks four times a week. Pre and post intervention respiratory muscle strength was evaluated by recording MIPmax and MEPmax values using Micro RPM. One Sample T-test was employed for pre and post training analysis, revealing significant (p=0.00) increase in post values of MIPmax and MEPmax in both experimental and conventional groups. Independent Sample T-test was employed which revealed significant increase in mean difference of MIPmax (p value 0.001) and MEPmax (p value 0.005) values for experimental group as compared to conventional group signifying comparative increase in respiratory muscle strength i.e. increase in mean difference of MIPmax (23.38%) and MEPmax (15.70%) in experimental group as compared to conventional group with threshold device training program. Respiratory muscle strength training using threshold device can help in inhibiting the metaboreflex which gets activated due to fatiguing respiratory muscles and with this training they can improve their output by taking less time to complete the race or covering more distance easily hence upgrading their race category.

Key words: Non-Elite Marathon Runners, Metaboreflex, MIPmax, MEPmax, Threshold Device, Inspiratory Muscle Strength Training.

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

INTRODUCTION

Marathon is a long-distance running race with an official distance of 42.195 kms usually run as a road race. The Mumbai Marathon is an annual international marathon held in Mumbai, India, on the third Sunday of January every year. It is the largest marathon in Asia as well as the largest mass participation sporting event on the continent. Mumbai Marathon has six different race categories: marathon (42.194 km), half marathon (21.097 km), Dream Run (6 km), Senior

Citizens Race (4.3 km), Champions with Disability category (2.4 km) and DHL Corporate

Champions (42.195 km, 4-person relay).

Respiratory muscle strength and endurance influence athletic performance [2] According to human anatomy diaphragm (DIA) and abdominal muscles have 50% slow-twitch (ST) fibres, but in intercostal muscles and the scalene it is 60%. All respiratory muscles show an equal distribution of fast-twitch (FTa and b) fibres except the expiratory intercostal muscles which have few FTb fibres. The inspiratory muscles have a uniform small fibre size, whereas the expiratory intercostal muscle fibres are large. The fibre size of the inspiratory muscles is maintained with ageing, whereas that of the expiratory intercostal muscles appears to be reduced after the age of 50 yrs.

Respiratory muscles can be trained through a device offering respiratory resistance. The Training

Device provides resistance to the muscles of ventilation.

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

The less trained Respiratory muscles can directly affect the output of the Athlete by activating

Metaboreflex. Metaboreflex gets activated when there is fatigue of respiratory muscles due to which the blood is pulled towards the fatigued respiratory muscles hence the peripheral muscle gets less oxygen; which results in reduced output by the peripheral muscles.

The fatiguing contractions of respiratory muscles and the consequent accumulation of metabolites activates type IV phrenic afferents resulting in increased sympathetic vasoconstrictor activity which causes a competition for blood flow between respiratory and working locomotor muscles.

The instrument used for this study was Threshold IMT device (Philips). [6] Threshold device is a commercially available device which provides resistance to the respiratory muscles thereby inhibiting the metaboreflex..

There has been limited literature regarding effect of respiratory muscle strength training in Non-

Elite Marathon Runners. Studies have been conducted to find the benefits of ventilatory muscle training but it is still not clear whether training the muscles of ventilation alone translates into clinically significant functional improvement.

Hence with this threshold device training we can thereby increase the strength of respiratory muscles which would lower the competition for blood supply which would in turn help the non- elite marathon runners to increase their lower limb muscle output.

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

METHODOLOGY

Sixty non elite half marathon runners were recruited from two sports clubs of Mumbai for the study. Written consent was obtained from the runners after duly informing them regarding purpose of study and intervention protocol. The inclusion criteria of the study were: male non elite runners in the age group of 35-55 years of age and participated in half marathon (21 kms) for at least two consecutive years. The exclusion criteria of the study were marathon runners diagnosed with any cardiovascular, respiratory or metabolic diseases and those who stopped participating in half marathon since a year. Comparative study was conducted with two groups consisting of thirty runners in each, fulfilling the inclusion criteria were randomly assigned to the Experimental (Group 1) and Conventional (Group 2) training protocols. Pre training strength of Inspiratory and Expiratory muscles was assessed by recording the values Maximal

Inspiratory Pressure (MIPmax) and Maximal Expiratory Pressure (MEPmax) using Micro

Respiratory Pressure Meter (Micro RPM) for both groups. Conventional training protocol for

Group 2 included a) Warm-up exercises – stretching of both upper and lower limbs for 10 minutes, b) Aerobic exercises – core muscle strengthening exercises for 10 minutes, spot jogging for 10 minutes followed by running for 10 minutes, c) Cool-down exercises – stretching of both upper and lower limbs and relaxed breathing exercises followed by shavasana for 10 minutes.

Experimental training protocol for Group 2 included a) Threshold IMT device training for 10 minutes, four times a week for a period six weeks. Initial resistance for training was set at 25% of their Pre- PImax and it was increased every week by 10 percent and b) Conventional exercise protocol. Both groups received respective training protocols for a period of six weeks. Post six weeks of training, values of MIPmax and MEPmax were recorded to evaluate the effects of training protocols.

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

RESULTS AND DISCUSSION

The data was analyzed using SPSS Software Version 20. Shapiro-Wilk test was used for normality analysis of the data which indicated that the data is normally distributed. Parametric tests of comparison i.e. paired and unpaired ‘t’ Test was used for the data analysis in the software.

This study was conducted to evaluate the effectiveness of threshold device on respiratory muscle strength of non-elite half marathon runners. Respiratory muscles can be trained through a device offering respiratory resistance. The instrument used for this study was Threshold IMT device

(Philips).

One Sample T-test was employed for the evaluation of pre and post MIPmax and MEPmax values, which revealed significant increase (i.e. p=0.00) in the post values of MIPmax and

MEPmax in both experimental and conventional groups stating that with or without threshold device training there was improvement in respiratory muscle strength, also there was found significant increase in mean difference of MIPmax i.e. 0.001 and MEPmax i.e. 0.005 values for experimental group as compared to conventional group by applying Independent Sample T-test, suggesting significant improvement in respiratory muscle strength of subjects in experimental group with threshold device training.

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

Figure 1

Comparison between the pre and post values of MIPmax and MEPmax within each group

98.6667 97.6 100 84.9667 86.1333 80.93333 80.3

80 65.1 67.5

60 PRE POST 40

0 GROUP1-MIP GROUP1 MEP GROUP2 MIP GROUP2 MEP

INFERENCE: There is significant increase in pre and post MIPmax and MEPmax values in both experimental and conventional groups.

Figure 2

Comparison of the pre and post MIPmax & MEPmax mean difference

15.83 20 12.83 11.46 13.26 CONVENTIONAL 0 EXPERIMENTAL MIP MEP

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

INFERENCE: There is significant increase in mean difference of MIPmax (23.38%) in experimental group as compared to conventional group and increase in mean difference of

MEPmax (15.70%) in experimental group as compared to conventional group.

Inspiratory muscle training has the potential to improve exercise tolerance. Threshold device is a commercially available device which provides resistance to the respiratory muscles thereby inhibiting the metaboreflex which is activated during heavy intensity exercise. When the respiratory muscle gets fatigued this reflex which is activated causes the blood to be pulled towards the fatiguing respiratory muscles instead of peripheral muscles which get less blood

&oxygen hence lower output of peripheral muscles.[4] The fatiguing contractions of respiratory muscles and the consequent accumulation of metabolites activates type IV phrenic afferents resulting in increased sympathetic vasoconstrictor activity which causes a competition for blood flow between respiratory and working locomotor muscles.[8] Hence with this threshold device training we can thereby increase the strength of respiratory muscles which would lower the competition for blood supply which would in turn help the non-elite marathon runners to increase their lower limb muscle output. This study tried to find out whether the threshold device improved their respiratory muscle strength. The result of this study showed that there is significant increase in MIP (p=0.001) and MEP (p=0.005) in experimental group as compared to control group (p<0.05).

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

CONCLUSIONS

The study focused on comparing the effects of threshold inspiratory muscle trainer device training versus conventional training program on respiratory muscle strength in non-elite half marathon runners. The results revealed that group 1 which received threshold device inspiratory muscle training protocol showed significant improvement of respiratory muscle strength after 6 weeks of intervention as compared to group 2 which received conventional training program.

Hence the study concluded that commercially available threshold inspiratory muscle trainer was more effective in improving respiratory muscle strength in non-elite half marathon runners.

RECOMMENDATIONS

*It is highly recommended to Marathon Runner coaches to include respiratory muscle training also in their daily protocol as the results of this study has revealed that threshold device training improves respiratory muscle strength.

*The results would help the coaches and administrators in planning and training of marathon runners for improving the standard of Marathon

*The study can be conducted in new non-elite marathon runners. Other available resistive devices can be used for further research. The study can also be conducted in patients suffering from cardiovascular or respiratory conditions using this easily available device.

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

REFERENCES

Agnihotri, D. S., Bhise, A. R., and Patel, S. M. (2016). Effect of Inspiratory Muscle Trainer on

Running Performance and Respiratory Muscle Strength in Athletes, IAIM 3(8). P. 160-

161.

Klusiewicz, A. (2014). Characteristics of the Inspiratory Muscle Strength in the Well-Trained

Male and Female Athletes. Biology of Sport. 25(1). P. 1.

Eastwood, P. R., Hillman, D. R., and Finucane, K. E. (2001). Inspiratory muscle performance in

endurance athletes and sedentary subjects. Respirology, 6(2). P. 95.

Dempsey, J. A., Romer, L., Rodman, J., Miller, J., and Smith, C. (2006). Consequences of

exercise-induced respiratory muscle work Respir Physiol Neurobiol, P. 151.

Kellens, I., Cannizzaro, F., Gouilly, P., and Crielaard, J. M. (2011). Inspiratory muscle strength

training in recreational athletes. Rev Mal Respir., 28(5). P. 1.

Karina Laohachai, and David Winlaw et al. (2017). Inspiratory Muscle Training Is Associated

With Improved Inspiratory Muscle Strength, Resting Cardiac Output, and the Ventilatory

Efficiency of Exercise in Patients With a Fontan Circulation. Journal of the American

Heart Association, 6. P. 2.

Mizuno, M. (1991). Human respiratory muscles: fibre morphology and capillary supply .European

Respiratory Journal. P. 587.

International Journal of Sports Sciences and Fitness, Volume 9(1) 2019

Rik Gosselink, Wagenaar, Robert C., and Marc Decramer. (1996). Reliability of a commercially

available threshold loading device in healthy subjects and in patients with chronic

obstructive pulmonary disease .Thorax, 51. P. 605.

ACKNOWLEDGEMENT

It is real pleasure that, I record my indebtedness to my mentor Dr. Vijayendra Rajguru (PT) for his counsel and guidance during the preparation of this research paper. I am also grateful to Prof.

Dr. Vrushali Panhale (PT) for all the suggestions offered and encouragement given to me. My sincere thanks to all the non-elite half marathon runners who participated for the study. With their voluntary and wholehearted support this study could not have been completed.