30 research outputs found
Influence of Xpand Nitric Oxide Reactor, L-Arginine Alpha-Ketoglutarate, and Caffeine Supplementation on Calf Muscle Re-Oxygenation During and after Acute Resistance Exercise
Xpand Nitric Oxide Reactor is a "cocktail" supplement proposed to improve skeletal muscle blood flow via arginine's effect on nitric oxide synthesis and vasodilation. Two other major ingredients, caffeine and creatine, cause vasoconstriction, which could potentially counteract the proposed hemodynamic effects of arginine. The purpose of this study was to examine the influence of Xpand Nitric Oxide Reactor on muscle re-oxygenation after resistance exercise compared to supplementation with constituent ingredients L-arginine alpha-ketoglutarate and caffeine. Nine recreationally active men (21±1y) performed 3 sets of 20 repetitions of seated single-leg calf raise at 60% 1-RM with 3 min rests. The same calf raise exercise was performed following 4 separate supplementation conditions: L-arginine alpha-ketoglutarate (AAKG), caffeine (CAFF), Xpand Nitric Oxide Reactor (XPAND), and placebo (PLAC). Soleus muscle re-oxygenation time was measured before, during, and immediately after exercise using near infrared spectroscopy. Supplementation with XPAND (0.43±0.03), AAKG (0.34±0.02), and CAFF (0.45±0.05) did not significantly affect muscle re-oxygenation halftime (minutes) compared to placebo (0.35±0.04). An arginine containing "cocktail" supplement did not affect skeletal muscle re-oxygenation after resistance exercise, possibly due to a wash-out effect caused by the multiple ingredients
Influence of Differences in Exercise-intensity and Kilograms/Set on Energy Expenditure During and After Maximally Explosive Resistance Exercise
With resistance exercise, greater intensity typically elicits increased energy expenditure, but heavier loads require that the lifter perform more sets of fewer repetitions, which alters the kilograms lifted per set. Thus, the effect of exercise-intensity on energy expenditure has yielded varying results, especially with explosive resistance exercise. This study was designed to examine the effect of exercise-intensity and kilograms/set on energy expenditure during explosive resistance exercise. Ten resistance-trained men (22±3.6 years; 84±6.4 kg, 180±5.1 cm, and 13±3.8 %fat) performed squat and bench press protocols once/week using different exercise-intensities including 48% (LIGHT-48), 60% (MODERATE-60), and 72% of 1-repetition-maximum (1-RM) (HEAVY-72), plus a no-exercise protocol (CONTROL). To examine the effects of kilograms/set, an additional protocol using 72% of 1-RM was performed (HEAVY-72MATCHED) with kilograms/set matched with LIGHT-48 and MODERATE-60. LIGHT-48 was 4 sets of 10 repetitions (4x10); MODERATE-60 4x8; HEAVY-72 5x5; and HEAVY-72MATCHED 4x6.5. Eccentric and concentric repetition speeds, ranges-of-motion, rest-intervals, and total kilograms were identical between protocols. Expired air was collected continuously throughout each protocol using a metabolic cart, [Blood lactate] using a portable analyzer, and bench press peak power were measured. Rates of energy expenditure were significantly greater (p≤0.05) with LIGHT-48 and HEAVY-72MATCHED than HEAVY-72 during squat (7.3±0.7; 6.9±0.6 \u3e 6.1±0.7 kcal/min), bench press (4.8±0.3; 4.7±0.3 \u3e 4.0±0.4 kcal/min), and +5min after (3.7±0.1; 3.7±0.2 \u3e 3.3±0.3 kcal/min), but there were no significant differences in total kcal among protocols. Therefore, exercise-intensity may not effect energy expenditure with explosive contractions, but light loads (~50% of 1-RM) may be preferred because of higher rates of energy expenditure, and since heavier loading requires more sets with lower kilograms/set
Energy Cost of Active and Sedentary Music Video Games: Handheld Gaming vs. Walking and Sitting
International Journal of Exercise Science 10(7): 1038-1050, 2017. To compare energy expenditure during and after active and handheld video game drumming compared to walking and sitting. Ten experienced, college-aged men performed four protocols (one per week): no-exercise seated control (CTRL), virtual drumming on a handheld gaming device (HANDHELD), active drumming on drum pads (DRUM), and walking on a treadmill at ~30% of VO2max (WALK). Protocols were performed after an overnight fast, and expired air was collected continuously during (30min) and after (30min) exercise. DRUM and HANDHELD song lists, day of the week, and time of day were identical for each participant. Significant differences (p \u3c 0.05) among the average rates of energy expenditure (kcal.min-1) during activity included WALK \u3e DRUM \u3e HANDHELD. No significant differences in the rates of energy expenditure among groups during recovery were observed. Total energy expenditure was significantly greater (p \u3c 0.05) during WALK (149.5 ± 30.6 kcal) compared to DRUM (118.7 ± 18.8 kcal) and HANDHELD (44.9±11.6 kcal), and greater during DRUM compared to HANDHELD. Total energy expenditure was not significantly different between HANDHELD (44.9 ± 11.6 kcal) and CTRL (38.2 ± 6.0 kcal). Active video game drumming at expert-level significantly increased energy expenditure compared to handheld, but it hardly met moderate-intensity activity standards, and energy expenditure was greatest during walking. Energy expenditure with handheld video game drumming was not different from no-exercise control. Thus, traditional aerobic exercise remains at the forefront for achieving the minimum amount and intensity of physical activity for health, individuals desiring to use video games for achieving weekly physical activity recommendations should choose games that require significant involvement of lower-body musculature, and time spent playing sedentary games should be a limited part of an active lifestyle
The relationships between workaholism and symptoms of psychiatric disorders: a large-scale cross-sectional study
Despite the many number of studies examining workaholism, large-scale studies have been lacking. The present study utilized an open web-based cross-sectional survey assessing symptoms of psychiatric disorders and workaholism among 16,426 workers (Mage = 37.3 years, SD = 11.4, range = 16–75 years). Participants were administered the Adult ADHD Self-Report Scale, the Obsession-Compulsive Inventory-Revised, the Hospital Anxiety and Depression Scale, and the Bergen Work Addiction Scale, along with additional questions examining demographic and work-related variables. Correlations between workaholism and all psychiatric disorder symptoms were positive and significant. Workaholism comprised the dependent variable in a three-step linear multiple hierarchical regression analysis. Basic demographics (age, gender, relationship status, and education) explained 1.2% of the variance in workaholism, whereas work demographics (work status, position, sector, and annual income) explained an additional 5.4% of the variance. Age (inversely) and managerial positions (positively) were of most importance. The psychiatric symptoms (ADHD, OCD, anxiety, and depression) explained 17.0% of the variance. ADHD and anxiety contributed considerably. The prevalence rate of workaholism status was 7.8% of the present sample. In an adjusted logistic regression analysis, all psychiatric symptoms were positively associated with being a workaholic. The independent variables explained between 6.1% and 14.4% in total of the variance in workaholism cases. Although most effect sizes were relatively small, the study’s findings expand our understanding of possible psychiatric predictors of workaholism, and particularly shed new insight into the reality of adult ADHD in work life. The study’s implications, strengths, and shortcomings are also discussed
Diagnosis and management of bone fragility in diabetes: an emerging challenge
Fragility fractures are increasingly recognized as a complication of both type 1 and type 2 diabetes, with fracture risk that increases with disease duration and poor glycemic control. Yet the identification and management of fracture risk in these patients remains challenging. This review explores the clinical characteristics of bone fragility in adults with diabetes and highlights recent studies that have evaluated bone mineral density (BMD), bone microstructure and material properties, biochemical markers, and fracture prediction algorithms (i.e., FRAX) in these patients. It further reviews the impact of diabetes drugs on bone as well as the efficacy of osteoporosis treatments in this population. We finally propose an algorithm for the identification and management of diabetic patients at increased fracture risk
Title from approval sheet: Effects of different resistance exercise protocols on Akt and ERK activation in human skeletal muscle
Akt activation mediates increases in glycogen synthesis in response to insulin in humans, while extracellular signal-regulated kinase (ERK) activation increases gene transcription and protein translation in response to endurance and resistance exercise. Akt activation increases only in response to intense muscle contractions and during hypertrophy in rats. No study has examined Akt and ERK activation with increasing numbers of intense muscle contractions in humans. Therefore, the primary objectives of this investigation were to determine if Akt activation increases in response to resistance exercise in humans, and to compare the changes in Akt and ERK activation in response to increasing numbers of muscle contractions.Akt and ERK activation were compared in muscle biopsy samples from 7 men before (Pre) and after (Post) knee extension and control protocols using enzyme linkedimmunosorbent assays. Baseline information was obtained including body composition and maximal strength (1-RM). Subjects were familiarized with knee extensions performed at 70% of 1-RM and a specified repetition cadence (2sec up, 2sec down). Once/wk, subjects performed one protocol in random order: 1 repetition (rep), 10reps, 3 sets of l0reps (3x10), or 6min of sitting. Akt activation decreased 42%, while ERK activation increased 108% in response to 3x10 (p<0.05). Akt and ERK activation did not change with 1 and 10reps, and thus their responses were not dose-dependent with resistance exercise in humans. The findings from this study represent the first indication that Akt activation is reduced in response to resistance exercise in human skeletal muscle, possibly to help mediate reductions in glycogen synthesis.Human Performance LaboratoryThesis (Ph.D.
Title from approval sheet: Effects of different resistance exercise protocols on Akt and ERK activation in human skeletal muscle
Akt activation mediates increases in glycogen synthesis in response to insulin in humans, while extracellular signal-regulated kinase (ERK) activation increases gene transcription and protein translation in response to endurance and resistance exercise. Akt activation increases only in response to intense muscle contractions and during hypertrophy in rats. No study has examined Akt and ERK activation with increasing numbers of intense muscle contractions in humans. Therefore, the primary objectives of this investigation were to determine if Akt activation increases in response to resistance exercise in humans, and to compare the changes in Akt and ERK activation in response to increasing numbers of muscle contractions.Akt and ERK activation were compared in muscle biopsy samples from 7 men before (Pre) and after (Post) knee extension and control protocols using enzyme linkedimmunosorbent assays. Baseline information was obtained including body composition and maximal strength (1-RM). Subjects were familiarized with knee extensions performed at 70% of 1-RM and a specified repetition cadence (2sec up, 2sec down). Once/wk, subjects performed one protocol in random order: 1 repetition (rep), 10reps, 3 sets of l0reps (3x10), or 6min of sitting. Akt activation decreased 42%, while ERK activation increased 108% in response to 3x10 (p<0.05). Akt and ERK activation did not change with 1 and 10reps, and thus their responses were not dose-dependent with resistance exercise in humans. The findings from this study represent the first indication that Akt activation is reduced in response to resistance exercise in human skeletal muscle, possibly to help mediate reductions in glycogen synthesis.Thesis (Ph.D.)Human Performance Laborator
Acute hormonal responses to a single bout of heavy resistance exercise in trained power lifters and untrained men
This is the publisher's version, also found at http://ehis.ebscohost.com/ehost/detail?sid=c58e4c93-cdad-411e-8971-ff871436da4b%40sessionmgr14&vid=1&hid=17&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=s3h&AN=SPHS-157498The purpose of this study was to investigate the acute responses of both stress and fluid regulatory hormones to a single bout of resistance exercise in both trained and untrained men. Seven competitive power lifters (PL) and 12 untrained subjects (UT) performed one set of the leg press exercise to exhaustion at 80 % of their respective one-repetition maximum. Blood samples were obtained twice prior to exercise (at P1 and P2), immediately postexercise (IP), and at 5 minutes postexercise (5PE). Compared to P1 and P2, plasma epinephrine, norepinephrine, dopamine, atrial peptide, osmolality, and blood lactic acid increased significantly (p less than or equal to 0.05) at IP. Plasma epinephrine, norepinephrine, atrial peptide, and blood lactic acid concentrations remained elevated at 5PE compared to P1 and P2. Plasma renin activity and angiotensin II were significantly elevated at 5PE compared to P1, P2, and IP, and this increase was significantly greater in PL compared to UT at 5PE. These data indicate that an acute bout of resistance exercise dramatically affects secretion of stress and fluid regulatory hormones