The Influence of a Slow-Breathing Protocol on Heart Rate and Blood Pressure from Exercise in Moderately Trained Females

International Journal of Exercise Science 12(2): 714-725, 2019. Heart rate recovery (HRR) and blood pressure recovery (BPR) from exercise are both important indicators of health and fitness and are strongly associated with cardiovascular disease. The purpose of this study was to compare the effects of a slow-breathing technique, upright passive recovery (PASS), and active recovery (ACT) on HRR and BPR from exercise. Nine moderately trained, college-aged (20.22 ± 0.97 yrs) female participants cycled three times on an ergometer for 15 mins at 70% of their heart rate maximum (HRmax), each of which was followed by one of three 5 min recovery interventions with heart rate (HR) and blood pressure (BP) objectively measured. Each participant completed all three recovery protocols. One recovery protocol consisted of breathing at a rate of 6 breaths per minute (BRE), another involved PASS and the third was ACT at 60 RPM and 25 W. A repeated measures ANOVA revealed there was a significant effect of protocol (p= 0.00, hp2= 0.67) with HRR. BRE resulted in the fastest HRR of 69 ± 9.31 bpm (40.12%) at the end of the 5 min recovery compared to 63 ± 10.60 bpm (36.57%) and 47 ± 12.54 bpm (27.34%) for PASS and ACT, respectively. A second repeated measures ANOVA indicated there was no effect of protocol (P = 0.43), nor was there a significant interaction with time (p= 0.68), for BPR. The results indicated that BRE increased HRR after exercise more rapidly than PASS or ACT with no influence on BPR. These findings lead to future research needed to explore different breathing protocols following exercise in at-risk populations, such as individuals with cardiovascular disease

Exploring the role of BMP7 gene expression in an In Vitro model of aging human skeletal muscle.

Sarcopenia is an age-related condition associated with rapid loss of skeletal muscle (SKM) tissue that affects mobility and quality of life of geriatric individuals. Mechanistic Target of Rapamycin (mTOR) and Protein Kinase B (AKT) have significant roles in SKM hypertrophy with responses to DNA damage and repair within SKM. However, mTOR and AKT expression is significantly decreased with age. Upstream of AKT, Bone Morphogenetic Protein (BMP7) is a member of the TGF-β signaling family that has been reported as a positive regulator of muscle hypertrophy through the Bmp–Smad1/5/8 signaling axis. PURPOSE: To use an in vitro model of aging muscle cells to investigate the role of BMP7 expression on protein synthesis. METHODS: Human SKM myoblasts were cultured and grown beyond mature myotube formation (typically day 6) to emulate aged SKM tissue (extracted on day 18). Groups included control cells (D6) and aged SKM myotubes (D18). Total RNA was extracted at the respective time points (days 6 & 18) and gene expression for BMP7, mTOR, and AKT was determined by qPCR. RESULTS: BMP7 expression was 7.73 fold greater for D18 compared to D6 (p \u3c 0.05). No differences were reported for AKT or mTOR. Data are expressed as fold changes. CONCLUSION: BMP7 expression, thought to be a positive regulator of muscle hypertrophy, was increased in the aging muscle cells of our model, despite our hypothesis that it would be decreased. However, BMP7’s downstream targets related to increased protein synthesis, mTOR and AKT, did not similarly increase from D6 to D18, which is constant with the phenomena of sarcopenia. This leads us to speculate that there may be additional mechanisms related to BMP7 activation and, despite increased signaling, may block protein synthesis at the level of AKT

Changes in Health and Physical Fitness Parameters After 6 Months of High-intensity Group Exercise in Firefighters: Preliminary Data

The physical demands of firefighting require the men and women employed in this profession to be in optimal physical condition to perform their jobs proficiently, as well as to mitigate the risk of injury. Every year, the city of Addison, TX, budgets many thousands of dollars to the compensation plan for first responders. Most of the funding is used for rehabilitation services due to work related injuries. PURPOSE: While many of these injuries are unavoidable due to the inherent risks of the profession, ensuring proper physical fitness is one of the most effective methods to reduce many of these impairments. The purpose of this preliminary study was to characterize health and fitness parameters in 18 professional firefighters from the city of Addison, TX, prior to a 6-month training program. METHODS: Upon arrival, all participants underwent testing in the following order: body composition, range of motion, anaerobic power, muscular endurance, and cardiorespiratory fitness. All participants also completed a detailed health history questionnaire and answered questions specifically addressing chronic low back pain. RESULTS: The following values were attained from testing: total body fat: 30.1±9.7%; flexibility: 24.9±6.3 cm; peak power: 1068.7±272.9 W; mean power: 636.9±143.4 W; time to peak power 0.57±0.35 sec; pushup: 28.8±14.9; curl up: 22.1±15.8; VO2max: 34.1±5.1 ml/kg/min. CONCLUSION: Based off the comparison of reported means and ACSM’s fitness norms, it can be concluded that improvements are necessary in body composition, muscular endurance, range of motion and cardiorespiratory fitness. With improvements in these physiological variables, tactical performance may be optimally performed in a safer manner

Myogenic Regulatory Factor Expression is Downregulated Following Formoterol Stimulation in Thyroid Hormone Depleted Skeletal Muscle

In skeletal muscle (SKM), gene expression of transcription factors regulating myogenesis are dependent on Thyroid Hormone (TH) signal transduction. Expression of myogenic regulatory factors may be altered due to dysregulated TH metabolism, which may result in SKM dysfunction and intolerance to exercise in individuals with hypothyroidism. PURPOSE: Implement an in vitro model of hypothyroidism in SKM and determine the response of myogenic regulatory factor expression during several stages of myogenesis following TH depletion. Formoterol, an exercise mimetic, was also used to examine the effects of exercise signaling on myogenesis in TH depleted cells. METHODS: Human SKM myoblasts (n = 6 per group) were cultured and differentiated until mature myotube formation (Day 6). Groups included control cells (CON), TH depleted cells (ThD), and TH depleted cells plus formoterol stimulation (ThD+F; 30nm for 3h). Total RNA was extracted during mid-myogenesis (Day 4) and at terminal differentiation (Day 6). Gene expression for myogenic regulatory factors (Myf5, MyoD, MyoG) was determined by qPCR. RESULTS: ThD decreased Myf5 at both Day 4 and Day 6 compared to control (P\u3c0.001). Myf5 was increased following ThD + F compared to ThD at Day 4 (P\u3c0.05). MyoD decreased following ThD at both Day 4 and Day 6 (P\u3c0.001). Further, MyoD was decreased following ThD + F at both Day 4 and Day 6 compared to ThD (P\u3c0.001). ThD had no effect on MyoG at Day 4 and Day 6; however, MyoG was decreased following ThD + F compared to ThD and control at both time points (P\u3c0.001). Data are expressed as mean ± SEM. CONCLUSION: TH depletion had no effect on MyoG but did reduce the expression of both Myf5 and MyoD at both Day 4 and Day 6. Additionally, ThD+F resulted in the lowest expression of MyoG and MyoD for both time points. These results indicate TH depletion and formoterol stimulation may inhibit myotube maturation

Mitochondrial Biogenesis is Dysregulated in Thyroid Hormone Depleted Muscle Cells Despite Stimulatory Effects of Formoterol

Skeletal muscle (SKM) is an important regulator of metabolism and adaptations from exercise training influences mitochondrial function. Thyroid hormone (TH) is a regulator of SKM processes, including mitochondrial biogenesis. PURPOSE: To use an in vitro model of hypothyroidism to test the hypothesis that SKM cells will have dysregulated mitochondrial homeostasis. Additionally, the exercise mimetic, formoterol, was used to determine the effects of exercise signaling on mitochondrial biogenesis. METHODS: Human SKM myoblasts (n = 6 per group) were cultured and differentiated until mature myotube formation (Day 6). Groups included control cells (CON), TH depleted cells (ThD), and TH depleted cells plus formoterol stimulation (ThD+F; 30nM for 3h). Total RNA was extracted during mid-myogenesis (Day 4) and at terminal differentiation (Day 6). Gene expression for Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha (PGC-1α), Mitochondrial Transcription Factor A (TFAM), and Nuclear Respiratory Factor 1 (NRF1) was determined by qPCR. Data was analyzed by repeated measures ANOVA. RESULTS: PGC-1α: D4 ThD was decreased compared to D4 ThD+F (-4.6); D4 ThD+F was increased compared to D4 CON (4.6); D6 CON was decreased compared to D6 ThD+F (-2.9); D6 ThD was decreased compared to D6 ThD+F (-3.7). TFAM: D4 ThD+F was greater than D4 CON (3.6); D4 ThD+F was greater than D6 ThD+F (3.6); D6 ThD was decreased compared to D6 CON (-0.55); D6 ThD+F was decreased compared to D6 CON (-0.63). NRF1: D4 ThD was decreased compared to D4 CON (-0.31); D4 ThD was greater than D4 ThD+F (0.36); D4 ThD was greater than D6 ThD (0.17); ThD+F was decreased compared to D4 CON (-0.67); D6 CON was decreased compared to D4 CON (-0.18); D6 ThD was decreased compared to D6 CON (-0.3); D6 ThD+F was decreased compared to D6 CON (-0.42). All reported differences are significant (p \u3c 0.05). Data are expressed as fold changes. CONCLUSION: ThD media resulted in reduced NRF1 signaling in both D4 and D6 with a subsequent decrease in D6 only for TFAM. Formoterol resulted in the expected stimulation of PGC-1α at both D4 and D6, but subsequent signaling for genes associated with mitochondrial biogenesis common to PGC-1α stimulation were lost as a result of TH depletion at D6 only for TFAM and both D4 and D6 for NRF1

Formoterol Stimulation In Vitro Influences Myogenic Regulatory Factors During Myogenesis in Human Skeletal Muscle Cells

The process of myogenesis within skeletal muscle (SKM) is essential for growth and repair and is coordinated via the expression of myogenic regulatory genes. Previous animal studies have reported that formoterol, a beta-adrenergic receptor agonist, has stimulating effects on genes related to SKM mitochondrial function and biogenesis, similar to effects found for exercise. Lesser known is the potential “exercise mimetic” influence that formoterol stimulation may have during the stages of myogenesis, especially in human SKM cells. PURPOSE: To investigate the effects of formoterol stimulation on expression of myogenic regulatory genes during myogenesis in human SKM cells. METHODS: Human SKM myoblasts (n = 6 per group) were cultured and differentiated until mature myotube formation (Day 6). Groups included control cells (CON) and cells stimulated by 30nM formoterol for 3h prior to RNA extraction points (FORM). Total RNA was extracted during mid-myogenesis (Day 4) and at terminal differentiation (Day 6) (a cell culture model of investigating myogenesis). Gene expression for Myogenic factor 5 (Myf5), Myogenic differentiation 1(MyoD), and Myogenin (MyoG) was determined by qPCR. Data was analyzed using repeated measures ANOVA. RESULTS: Myf5: There was no change for either condition for D4. D6 CON was lower than D4 CON (-0.25). D6 FORM was greater than D4 FORM (0.65) and D6 CON (0.75). MyoD: D4 FORM was lower than D4 CON (-0.57). D6 FORM was greater than D4 FORM (0.85) and lower than D6 CON (-0.16). D6 CON was lower than D4 CON (-0.33). MyoG: D4 FORM was lower than D4 CON (-0.72). D6 CON was lower than D4 CON (-0.44). D6 FORM was lower than D6 CON (-0.24). All reported differences are significant (p \u3c 0.05). Data are expressed as fold changes. CONCLUSION: As expected, for the CON group, Myf5, MyoD, and MyoG expression all decreased from D4 mid-myogenesis to D6 terminal myogenesis, indicating finalization of the myogenic gene program. For the FORM group, Myf5 expression was elevated at D6 compared to CON while MyoG and MyoD expression was lower than CON for D4 and D6. The interpretation is that FORM stimulation increased stimulus of D4 myoblast proliferation and, thus, delayed initiation of differentiation. These results, coupled with other preliminary data from our lab showing increased mitochondrial biogenesis with this model of investigation, suggests that this exercise mimetic stimulation may cause shift in the cell towards bioenergetic preference rather than fusion of myotubes

Heart Rate and Blood Pressure Recovery Responses to Different Modes of Recovery Following Moderate Intensity Exercise in Females

Heart rate (HR) and blood pressure (BP) increases during exercise to meet metabolic demands through parasympathetic nervous system (PNS) withdrawal and sympathetic nervous system (SNS) stimulation. Heart rate recovery (HRR) and blood pressure recovery (BPR) following exercise are both important factors related to cardiovascular health. PURPOSE: The purpose of this study was to examine the effects of a slow-breathing technique compared to other forms of recovery on HRR and BPR following moderate-intensity exercise. METHODS: Nine moderately-active (20.22 ± 0.97 years) female participants cycled at 70% of their heart rate maximum (HRmax) on a cycle ergometer for 15 min, followed by one of three 5 min recovery interventions: 6 breaths per minute (BRE), active recovery (ACT) at 60 RRM and 25 W resistance, and passive recovery (PASS). All participants completed each recovery protocol on three separate occasions. HR and BP were recorded during each recovery protocol and converted to HRR and BPR by subtracting the recovery values from the average HR and BP of the last 5 min of exercise. Repeated measures ANOVA with a Greenhouse-Geisser correction was used for statistical analyses for both HRR and BPR. RESULTS: Repeated measures ANOVA revealed there was a significant main effect of protocol (p \u3c 0.05, hp2 = 0.67) and time (p \u3c 0.001, hp2 = 0.93) for HRR. There was no interaction effect found for HRR (p = 0.12). BRE resulted in the fastest HRR (40.12%) at the end of the 5 min recovery period compared to PASS (36.57%) and ACT (27.34%). A significant main effect of time (p \u3c 0.001, hp2 = 0.73) was found for BPR with no main effect for protocol (p = 0.43) nor interaction effect (p = 0.68) found. CONCLUSION: A slow-breathing recovery protocol enhances HRR, but not BPR, when compared to active recovery and passive recovery in moderately-active females

An In Vitro Investigation Of The Effects Of Formoterol On Thyroid Hormone-Related Gene Expression During Myogenesis

Thyroid hormone (TH) is a primary driver of skeletal muscle (SKM) metabolism as well as myogenesis through stimulation its genetic targets. The conversion and activation of thyroid hormone (T4 to T3) is controlled by local deiodinase 2 and 3 (DIO2, DIO3) activity. This leads to expression of nuclear receptors in promotor regions of specific genes including sarco/endoplasmic reticulum calcium ATPase 1(SERCA1), which is important for homeostasis of calcium regulation during muscle contraction. PURPOSE: The purpose of the study was to examine the effects of the exercise mimetic Formoterol (FORM), a beta-adrenergic receptor agonist, on the expression of thyroid hormone-related genes during myogenesis In Vitro. METHODS: Commercially obtained, primary, human SKM myoblasts (n = 4) were cultured and differentiated for one day before initiation of daily treatment of 30 nM FORM or vehicle, dimethyl sulfoxide (DMSO) which continued until day 6 of differentiation. Total RNA was extracted on one day (D1), four days (D4), and six days (D6) post differentiation. Gene expression for DIO2, DIO3, SERCA1, SERCA2, thyroid hormone receptor α (THRα), and thyroid hormone receptor β (THRβ) was analyzed by qPCR. RESULTS: Expression of DIO2 decreased from D1 to D4 for both DMSO (P\u3c0.001) and FORM (P\u3c0.05). Similarly, DIO2 decreased from D1 to D6 for both DMSO (P\u3c0.001) and FORM (P\u3c0.001) treatment. DIO3 expression decreased from D1 to D6 for both DMSO and FORM (P\u3c0.05) treatments. THRα expression decreased from D1 to D4 for both DMSO (P\u3c0.05) and FORM (P\u3c0.001). THRβ expression decreased from D1 to D6 for both DMSO and FORM (P\u3c0.05). SERCA1 expression only decreased for DMSO between D1 and D6 (P\u3c0.05). No differences were found for SERCA2. CONCLUSION: Conversion of TH by DIO2 and DIO3 is an important mechanism regulating proliferation and differentiation during myogenesis. During cell culture, cells do not receive signals for activity as found In Vivo, thus mimicking sedentary behavior and resulting in decreased thyroid hormone related gene expression. In our study, FORM appeared to prevent the decrease found for SERCA1 expression in the DMSO treatment, indicating that “exercise” stimulation can increase or maintain calcium pump activity as compared to “sedentary” muscle conditions. It is possible that exercise stimulates the expression of genes related to TH signaling and metabolism during myogenesis. Future studies with Formoterol treatment will explore additional treatment timelines and genetic targets for analysis

Exercise Participation and Indicators of Skeletal Muscle Health in Women with Hypothyroidism

Women with hypothyroidism report undesirable skeletal muscle symptoms at rest and during exercise. The severity of skeletal muscle symptoms may influence an individual’s willingness and capacity to exercise. PURPOSE: This study aimed to determine the relationship between exercise and skeletal muscle symptoms at rest and during exercise in women with hypothyroidism. METHODS: An online survey was completed by female participants diagnosed with hypothyroidism currently undergoing prescribed thyroid hormone treatment (n=580). Participants responded to questions related to basal muscle symptoms (MS), and muscle pain (MP) and fatigue (MF) experienced during exercise. Participants reported the type of exercise they performed, including: no exercise (NE), cardiovascular/aerobic (CV), resistance training (RT), or cardiovascular and resistance training (CVRT). Frequency of exercise and recovery time from exercise were also reported. RESULTS: Participants performing CVRT reported significantly lower MS at rest compared to CV (PCONCLUSION: Results from this study indicate performing CVRT may improve skeletal muscle symptoms in women with hypothyroidism

Whey Protein Supplementation Improves the Glycemic Response and May Reduce Non-Alcoholic Fatty Liver Disease Related Biomarkers in Women with Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) increases type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) with insulin resistance. We hypothesized that a 35 g whey preload would improve insulin sensitivity and glucose handling while reducing biomarkers associated with NAFLD. Twenty-nine age-matched women (CON = 15, PCOS = 14) completed oral glycemic tolerance tests following baseline (Day 0) as well as an acute (Day 1) and short-term whey supplementation (Day 7). Whey had an interaction effect on glucose (p = 0.02) and insulin (p = 0.03), with glucose remaining stable and insulin increasing with whey supplementation. Insulin sensitivity (p < 0.01) improved with whey associated with increased glucagon secretion (p < 0.01). Alanine aminotransferase (ALT), and aspartate aminotransferase (AST) remained unchanged, but “day” had an effect on the AST:ALT ratio (p = 0.04), whereas triglycerides and sex hormone binding globulin overall were greater in the PCOS group (p < 0.05). Total cholesterol decreased in PCOS (by 13%) and CON (by 8%) (NS). HepG2 cells treated with plasma from participants before and after whey decreased lipid accumulation in the PCOS group after whey (p < 0.05). Whey provided an insulinogenic and glycemic homeostatic effect in women with PCOS with the potential to combat NAFLD-consequences