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Date Permissions Signed


Date of Award


Document Type

Masters Thesis

Degree Name

Master of Education (MEd)


Health and Human Development

First Advisor

Brilla, Lorraine R., 1955-

Second Advisor

Knutzen, Kathleen

Third Advisor

Row, Brandi


The purpose of this investigation was to evaluate the effect of six weeks of inspiratory muscle training (IMT) on heart rate variability (HRV) in young and older adults. Twelve young (age 22.25 + 2.13 years) and 14 older adults (age 72.5 + 6.44 years) participated in the study. The training protocol included using IMT device set at a resistance equivalent to 80% of maximal inspiratory pressure (MIP), five days per week. HRV data were obtained by electrocardiogram prior to and following six weeks of IMT, along with pulmonary function measures (vital capacity, forced expiratory volume in one second, maximal ventilatory volume). The HRV variables included total power (TP), very low frequency (VLF), low frequency (LF), and high frequency (HF) powers. In addition, normalized LF (LFnu), normalized HF (HFnu) and LF to HF ratio (LF/HF) were analyzed. The results from the young group demonstrated a significant increase in HFnu (pre 0.22 + 0.039, post 0.243 + 0.059 nu, p < 0.05), and a significant decrease in LFnu (pre 0.779 + 0.039, post 0.756 + 0.059 nu, p < 0.05) and LF/HF (pre 3.651 + 0.756, post 3.278 + 0.787, p < 0.05). In the older group, HFnu decreased significantly (pre 0.236 + 0.076, post 0.205 + 0.03 nu, p < 0.05) along with significant increases in LFnu (0.763 + 0.076, post 0.794 + 0.03 nu, p < 0.05) and LF/HF (pre 3.551 + 1.08, post 3.94 + 0.574, p < 0.05). No significant change was observed in any of TP, LF or HF. Both the groups demonstrated a significant increase in inspiratory muscle strength as determined by MIP (Young: pre 1.06 + 0.33, post 1.68 + 0.38; Older: pre 0.72 + 0.24 cm, post 0.98 + 0.14 cmH2O) (p < 0.05) and the pulmonary function measures. The results of this study demonstrated that IMT had a training effect on not only inspiratory muscle strength but also HRV. However, the training response varied within groups. The young group demonstrated a shift in autonomic balance towards parasympathetic modulation, while the older group demonstrated decrease in parasympathetic modulation.





Western Washington University

OCLC Number


Subject – LCSH

Heart beat; Muscle strength; Respiratory muscles; Exercise--Physiological aspects; Aging--Exercise




masters theses




Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

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