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Item Association of Obstructive Sleep Apnea Severity with Exercise Capacity and Health-related Quality of Life(Wolters Kluwer, 2013) Butner, Katrina L.; Hargens, Trent A.; Kaleth, Anthony S.; Miller, Larry E.; Zedalis, Donald; Herbert, William G.; Exercise & Kinesiology, School of Health and Human SciencesBackground: Current research is inconclusive as to whether obstructive sleep apnea severity directly limits exercise capacity and lowers health-related quality of life (HRQoL). Aims: The aim of this study was to evaluate the association of obstructive sleep apnea severity with determinants of exercise capacity and HRQoL. Subjects and methods: Subjects were evaluated by home somnography and classified as no obstructive sleep apnea (n = 43) or as having mild (n = 27), moderate or severe obstructive sleep apnea (n = 21). Exercise capacity was assessed by a ramping cycle ergometer test, and HRQoL was assessed with the SF-36 questionnaire. Results: Greater obstructive sleep apnea severity was associated with older age, higher body weight, higher body mass index, lower peak aerobic capacity, a higher percentage of peak aerobic capacity at a submaximal exercise intensity of 55 watts, and lower physical component summary score from the SF-36. None of these variables were statistically different among obstructive sleep apnea severity groups after controlling for age and body weight. Obstructive sleep apnea severity was not associated with any cardiorespiratory fitness or HRQoL parameter. Conclusions: Obstructive sleep apnea severity has no independent association with exercise capacity or HRQoL.Item The nociceptive withdrawal reflex does not adapt to joint position change and short-term motor practice(Taylor & Francis, 2013-07-16) Eckert, Nathan; Riley, Zachary A.; Exercise & Kinesiology, School of Health and Human SciencesThe nociceptive withdrawal reflex is a protective mechanism to mediate interactions within a potentially dangerous environment. The reflex is formed by action-based sensory encoding during the early post-natal developmental period, and it is unknown if the protective motor function of the nociceptive withdrawal reflex in the human upper-limb is adaptable based on the configuration of the arm or if it can be modified by short-term practice of a similar or opposing motor action. In the present study, nociceptive withdrawal reflexes were evoked by a brief train of electrical stimuli applied to digit II, 1) in five different static arm positions and, 2) before and after motor practice that was opposite (EXT) or similar (FLEX) to the stereotyped withdrawal response, in 10 individuals. Withdrawal responses were quantified by the electromyography (EMG) reflex response in several upper limb muscles, and by the forces and moments recorded at the wrist. EMG onset latencies and response amplitudes were not significantly different across the arm positions or between the EXT and FLEX practice conditions, and the general direction of the withdrawal response was similar across arm positions. In addition, the force vectors were not different after practice in either the practice condition or between EXT and FLEX conditions. We conclude the withdrawal response is insensitive to changes in elbow or shoulder joint angles as well as remaining resistant to short-term adaptations from the practice of motor actions, resulting in a generalized limb withdrawal in each case. It is further hypothesized that the multisensory feedback is weighted differently in each arm position, but integrated to achieve a similar withdrawal response to safeguard against erroneous motor responses that could cause further harm. The results remain consistent with the concept that nociceptive withdrawal reflexes are shaped through long-term and not short-term action based sensory encoding.Item Nociceptive Influence on Cortical Output within Proximal-Distal Muscles in the Upper-Limb(Elsevier, 2021) Eckert, Nathanial R.; Greenwell, Davin; Poston, Brach; Riley, Zachary A.; Exercise & Kinesiology, School of Health and Human SciencesA single pulse of high intensity electrical current delivered to the digits of the hand during voluntary contractions produces a period of decreased electromyographic (EMG) activity, known as a cutaneous silent period (CSP) (Caccia G and Violini A, 1973; Inghilleri M et al., 1997). Pairing transcranial magnetic stimulation (TMS) with digit stimulation results in motor evoked potentials (MEPs) with reduced amplitudes in thenar muscle (Kofler, 2008). It is not known if similar behavior can be observed in more proximal upper-limb muscles. The current study investigated the CSP on several muscles throughout the upper-limb. 14 subjects performed isometric contractions with the following muscles: abductor pollicis brevis (APB), flexor carpi radialis (FCR), extensor carpi radialis (ECR), biceps brachii (BIC), triceps brachii (TRI), anterior deltoid (AD), and posterior deltoid (PD). During the isometric contractions, subjects experienced three different stimulation conditions: electrical stimulation (10x perceptual threshold) of digit II only (CSP), transcranial magnetic stimulation only (TMS), and digit II stimulation plus TMS (TMS+). The TMS evoked MEP was significantly greater than TMS+ MEP for APB ( p <0.001), FCR ( p =0.006), and BIC ( p <0.049) muscles. The opposite relationship was seen within the PD ( p <0.047) muscle. An ANOVA test of normalized MEP values (TMS+/TMS) showed significant differences in APB vs TRI ( p = 0.004) and PD ( p = 0.003), and in FCR vs TRI ( p = 0.046) and PD ( p = 0.037) muscles. The results suggest that the CSP modulates descending drive differentially across upper-limb muscles.Item Physical play - How do we inspire and motivate young children to be physically active through play? An international analysis of twelve countries’ national early years curriculum policies and practices for physical activity and physical play(2023-02) Howells, Kristy; Jerebine, Alethea; Cools, Wouter; D'Hondt, Eva; De Martelaer, Kristine; Coppens, Eline; Sienaert, Helena; Hall, Nathan; Dong, Jinxia; Soini, Anne; O'Keeffe, Christina; Coulter, Maura; McNally, Sinéad; McCaffrey, Patricia; Tortella, Patrizia; Costa, Aldo M.; Hernández-Martinez, Andrea; Sollerhed, Ann-Christin; Urtel, Mark; Vinci, Debra; Wirth, Christopher; Vidoni, Carla; Sääkslahti, Arja; Exercise & Kinesiology, School of Health and Human SciencesLifelong movement and physical activity (PA) patterns develop during early childhood. Therefore, educators (teachers and practitioners) in early childhood education and care (ECEC) should provide opportunities to support children’s play, PA, and movement development. The World Health Organization (2019) offers new recommendations for PA, for children under five years. The guidelines do not specify the ways ECEC staff can support PA through play. Therefore, this paper investigates, how physical play (PP) is enacted globally. An international policy and practice analysis of twelve countries, (Australia [Victoria], Belgium [Flanders], Canada [Alberta], China, Finland, Ireland, Italy, Portugal, Spain, Sweden, UK [England] and USA) was completed by analyzing the ECEC curricula and their implementation in different cultural contexts. A content analysis was undertaken by AIESEP Early Years SIG experts revealing that PP was not clearly defined. When defined, it was described as PA, and important for children’s holistic development. The majority of curricula did not state the length/time for PP. Three main strategies for implementing PP were found: a) pedagogical framework; b) active learning methods; and c) motor development. This international analysis highlights the global need for better ECEC staff support in acknowledging and implementing PP to aid children’s overall development, PA and wellbeing.Item Pilot randomized trial of the effect of antibacterial mouthwash on muscle contractile function in healthy young adults(Public Library of Science, 2025-02-12) Gallardo, Edgar J.; Zoughaib, William S.; Singhal, Ahaan; Hoffman, Richard L.; Coggan, Andrew R.; Exercise & Kinesiology, School of Health and Human SciencesAntiseptic mouthwash use is widespread due to its oral health benefits. However, its impact on systemic physiological processes, particularly nitric oxide (NO) bioavailability and muscle contractility, is not fully understood. We sought to determine the effects of cetylpyridinium (antibacterial) versus sodium chloride (control) mouthwashes on salivary and breath NO markers and muscle contractile function in healthy young adults. Thirty participants (n = 15/group) completed a randomized, parallel-arm, blinded trial, comparing the two mouthwashes before and after 7 d of treatment. NO bioavailability was inferred via measurement of salivary nitrate (NO3-), nitrite (NO2-), and cyclic guanyl monophosphate (cGMP) concentrations and breath NO level. Contractile function of the knee extensor muscles was determined via isokinetic dynamometry. No changes in salivary NO3-, NO2-, or cGMP or in breath NO were observed in response to either treatment. However, cetylpyridinium mouthwash reduced the percentage of NO2- in saliva (17 ± 10% vs. 25 ± 13%; p = 0.0036). Peak torque at velocities of 0-6.28 rad/s was unaffected by mouthwash use. Calculated maximal knee extensor velocity (Vmax) and power (Pmax) were therefore also unchanged. Cetylpyridinium mouthwash reduces the relative abundance of NO2- in the oral cavity but does not significantly diminish overall NO bioavailability or impair muscle contractile function in healthy young adults.Item Beeting atrophy: dietary nitrate to protect the powerhouse of the cell?(Wiley, 2023-07-31) Zoughaib, William S.; Brault, Jeffrey J.; Coggan, Andrew R.; Exercise & Kinesiology, School of Health and Human SciencesItem Short-term beetroot juice supplementation improves muscle speed and power but does not reduce blood pressure or oxidative stress in 65–79 y old men and women(Elsevier, 2023-09) Zoughaib, William S.; Hoffman, Richard L.; Yates, Brandon A.; Moorthi, Ranjani N.; Lim, Kenneth; Coggan, Andrew R.; Exercise & Kinesiology, School of Health and Human SciencesWe have previously demonstrated that acute ingestion of inorganic nitrate (NO3−)-rich beetroot juice (BRJ), a source of nitric oxide (NO) via the NO3− → nitrite (NO2−) → NO pathway, can improve muscle speed and power in older individuals. It is not known, however, whether this effect is maintained or perhaps even enhanced with repeated ingestion, or if tolerance develops as with organic nitrates, e.g., nitroglycerin. Using a double-blind, placebo-controlled, crossover design, we therefore studied 16 community-dwelling older (age 71 ± 5 y) individuals after both acute and short-term (i.e., daily for 2 wk) BRJ supplementation. Blood samples were drawn and blood pressure was measured periodically during each ∼3 h experiment, with muscle function determined using isokinetic dynamometry. Acute ingestion of BRJ containing 18.2 ± 6.2 mmol of NO3− increased plasma NO3− and NO2− concentrations 23 ± 11 and 2.7 ± 2.1-fold over placebo, respectively. This was accompanied by 5 ± 11% and 7 ± 13% increases in maximal knee extensor speed (Vmax) and power (Pmax), respectively. After daily supplementation for 2 wk, BRJ ingestion elevated NO3− and NO2− levels 24 ± 12 and 3.3 ± 4.0-fold, respectively, whereas Vmax and Pmax were 7 ± 9% and 9 ± 11% higher than baseline. No changes were observed in blood pressure or in plasma markers of oxidative stress with either acute or short-term NO3− supplementation. We conclude that both acute and short-term dietary NO3− supplementation result in similar improvements in muscle function in older individuals. The magnitudes of these improvements are sufficient to offset the decline resulting from a decade or more of aging and are therefore likely to be clinically significant.Item Short-term beetroot juice supplementation improves muscle speed and power but does not reduce blood pressure or oxidative stress in 65–79 y old men and women(Elsevier, 2023) Zoughaib, William S.; Hoffman, Richard L.; Yates, Brandon A.; Moorthi, Ranjani N.; Lim, Kenneth; Coggan, Andrew R.; Exercise & Kinesiology, School of Health and Human SciencesWe have previously demonstrated that acute ingestion of inorganic nitrate (NO3-)-rich beetroot juice (BRJ), a source of nitric oxide (NO) via the NO3- → nitrite (NO2-) → NO pathway, can improve muscle speed and power in older individuals. It is not known, however, whether this effect is maintained or perhaps even enhanced with repeated ingestion, or if tolerance develops as with organic nitrates, e.g., nitroglycerin. Using a double-blind, placebo-controlled, crossover design, we therefore studied 16 community-dwelling older (age 71 ± 5 y) individuals after both acute and short-term (i.e., daily for 2 wk) BRJ supplementation. Blood samples were drawn and blood pressure was measured periodically during each ∼3 h experiment, with muscle function determined using isokinetic dynamometry. Acute ingestion of BRJ containing 18.2 ± 6.2 mmol of NO3- increased plasma NO3- and NO2- concentrations 23 ± 11 and 2.7 ± 2.1-fold over placebo, respectively. This was accompanied by 5 ± 11% and 7 ± 13% increases in maximal knee extensor speed (Vmax) and power (Pmax), respectively. After daily supplementation for 2 wk, BRJ ingestion elevated NO3- and NO2- levels 24 ± 12 and 3.3 ± 4.0-fold, respectively, whereas Vmax and Pmax were 7 ± 9% and 9 ± 11% higher than baseline. No changes were observed in blood pressure or in plasma markers of oxidative stress with either acute or short-term NO3- supplementation. We conclude that both acute and short-term dietary NO3- supplementation result in similar improvements in muscle function in older individuals. The magnitudes of these improvements are sufficient to offset the decline resulting from a decade or more of aging and are therefore likely to be clinically significant.Item Sex-Specific Skeletal Muscle Gene Expression Responses to Exercise Reveal Novel Direct Mediators of Insulin Sensitivity Change(medRxiv, 2024-09-08) Ma, S.; Morris, M. C.; Hubal, M. J.; Ross, L. M.; Huffman, K. M.; Vann, C. G.; Moore, N.; Hauser, E. R.; Bareja, A.; Jiang, R.; Kummerfeld, E.; Barberio, M. D.; Houmard, J. A.; Bennett, W. B.; Johnson, J. L.; Timmons, J. A.; Broderick, G.; Kraus, V. B.; Aliferis, C. F.; Kraus, W. E.; Exercise & Kinesiology, School of Health and Human SciencesBackground: Understanding the causal pathways, systems, and mechanisms through which exercise impacts human health is complex. This study explores molecular signaling related to whole-body insulin sensitivity (Si) by examining changes in skeletal muscle gene expression. The analysis considers differences by biological sex, exercise amount, and exercise intensity to identify potential molecular targets for developing pharmacologic agents that replicate the health benefits of exercise. Methods: The study involved 53 participants from the STRRIDE I and II trials who completed eight months of aerobic training. Skeletal muscle gene expression was measured using Affymetrix and Illumina technologies, while pre- and post-training Si was assessed via an intravenous glucose tolerance test. A novel gene discovery protocol, integrating three literature-derived and data-driven modeling strategies, was employed to identify causal pathways and direct causal factors based on differentially expressed transcripts associated with exercise intensity and amount. Results: In women, the transcription factor targets identified were primarily influenced by exercise amount and were generally inhibitory. In contrast, in men, these targets were driven by exercise intensity and were generally activating. Transcription factors such as ATF1, CEBPA, BACH2, and STAT1 were commonly activating in both sexes. Specific transcriptional targets related to exercise-induced Si improvements included TACR3 and TMC7 for intensity-driven effects, and GRIN3B and EIF3B for amount-driven effects. Two key signaling pathways mediating aerobic exercise-induced Si improvements were identified: one centered on estrogen signaling and the other on phorbol ester (PKC) signaling, both converging on the epidermal growth factor receptor (EGFR) and other relevant targets. Conclusions: The signaling pathways mediating Si improvements from aerobic exercise differed by sex and were further distinguished by exercise intensity and amount. Transcriptional adaptations in skeletal muscle related to Si improvements appear to be causally linked to estrogen and PKC signaling, with EGFR and other identified targets emerging as potential skeletal muscle-specific drug targets to mimic the beneficial effects of exercise on Si.Item Angiogenic potential of skeletal muscle derived extracellular vesicles differs between oxidative and glycolytic muscle tissue in mice(Nature, 2023-11) Kargl, Christopher K.; Jia, Zhihao; Shera, Deborah A.; Sullivan, Brian P.; Burton, Lundon C.; Kim, Kun Ho; Nie, Yaohui; Hubal, Monica J.; Shannahan, Jonathan H.; Kuang, Shihuan; Gavin, Timothy P.; Exercise & Kinesiology, School of Health and Human SciencesSkeletal muscle fibers regulate surrounding endothelial cells (EC) via secretion of numerous angiogenic factors, including extracellular vesicles (SkM-EV). Muscle fibers are broadly classified as oxidative (OXI) or glycolytic (GLY) depending on their metabolic characteristics. OXI fibers secrete more pro-angiogenic factors and have greater capillary densities than GLY fibers. OXI muscle secretes more EV than GLY, however it is unknown whether muscle metabolic characteristics regulate EV contents and signaling potential. EVs were isolated from primarily oxidative or glycolytic muscle tissue from mice. MicroRNA (miR) contents were determined and endothelial cells were treated with OXI- and GLY-EV to investigate angiogenic signaling potential. There were considerable differences in miR contents between OXI- and GLY-EV and pathway analysis identified that OXI-EV miR were predicted to positively regulate multiple endothelial-specific pathways, compared to GLY-EV. OXI-EV improved in vitro angiogenesis, which may have been mediated through nitric oxide synthase (NOS) related pathways, as treatment of endothelial cells with a non-selective NOS inhibitor abolished the angiogenic benefits of OXI-EV. This is the first report to show widespread differences in miR contents between SkM-EV isolated from metabolically different muscle tissue and the first to demonstrate that oxidative muscle tissue secretes EV with greater angiogenic signaling potential than glycolytic muscle tissue.