Exercise Time Duration Research Articles

Cross-sectional associations of weekly time, social context, and motivation of exercise with mental health among workers.

Exercise is considered a strategy to promote mental health among workers. However, the optimal exercise conditions that promote mental health benefits for workers are still unclear. This study examined the cross-sectional associations of weekly exercise time duration, social context of exercise, and exercise motivation levels with the mental health among Japanese workers. A web-based cross-sectional questionnairesurvey was conducted among 18,902 workers, aged 20-59 years. The mental health variables (psychological distress, psychological stress reaction, physical stress reaction, job satisfaction, and work engagement), exercise participation (non-exercisers, exercisers), and demographic factors of all responders were measured. Weekly exercise time, social context of exercise (alone only, with others only, both alone and with others), and exercise motivation (non-regulation, external/introjected regulation, identified regulation, integrated regulation, and internal regulation) were also measured amongst exercisers. After adjusting for demographic factors, multiple regression analyses were conducted. Exercisers had significantly lower psychological distress, lower psychological and physical stress reactions, higher job satisfaction, and higher work engagement than non-exercisers. Among exercisers, while weekly exercise time duration and social context of exercise were not clearly and robustly associated with mental health variables, respondents with intrinsic regulation had significantly lower psychological distress, lower psychological and physical stress reaction, higher job satisfaction, and higher work engagement than those with lower self-determined motivations. This study found that more self-determined exercise motivation is closely associated with advantageous mental health variables, than the duration or the social context of exercise among Japanese workers.

Aerobic Capacity in Adults with Congenital Heart Disease: More than VO2peak, a Follow-Up Study.

To control the development of people with congenital heart disease (CHD), it is important to follow their aerobic capacity (AC), especially when they exercise. This research aimed to study the progress of AC during a follow-up of adults with CHD. This is a longitudinal study which involved 127 adults with a mean age of 33.8 (11.1) years (57.5% female; 75 moderate CHD and 52 complex CHD) who had undergone two cardiopulmonary exercise tests (CEPT) in at least one year between the first and the second test. The AC and exercise performance (EP) (duration of exercise time, velocity and percentage of grade) were assessed using a ramp protocol over a treadmill. In a mean of 4.5 (2.0) years of follow-up, there was a significant decrease in AC. The VO2peak at baseline was 27.8 (27.7) mL/kg/min (82.9% (20.3%) predicted) versus 26.6 (7.8) mL/kg/min (79.3% (20.8%) predicted) at the end of follow-up. This decline was independent of the body weight increase. There was no significant difference in HRpeak and EP among periods. These results suggest a sign of favorable evolution of adults with CHD. More research is needed to study different factors that could contribute to AC reduction.

Exercise Performance And Aerobic Capacity In Adults With Congenital Heart Disease: A Follow-up Study

In order to control de development of persons with congenital heart disease, it is important to follow their aerobic capacity (AC), especially when they exercise. PURPOSE: To study the progress of Exercise Performance (EP) and AC in the follow-up of adults with congenital heart disease (CHD). METHODS: A longitudinal study with 127 adults with a mean age of 33.77 years (11.57) (71 women; and 56 men) who have undergone two cardiopulmonary exercise test (CEPT) in at least one year between the first and the second test. The AC and EP were assessed by a CPET using a ramp protocol over a treadmill obtaining cardiovascular and metabolic data. Participants started walking at 3 km/h and 0% grade for two minutes, increasing the speed 0.3 km/h, and 1.4% grade every minute to a maximum of 12% until exhaustion. Descriptive for all variables were obtained, and an analysis of variance (ANOVA one way; post-hoc Bonferroni) to evaluate significant differences among the first and the second CPET in the VO2Peak, body weight, time of effort, maximal velocity and % grade was applied. RESULTS: A significant decrease of AC appeared, where the VO2Peak in the first CPET was 27.73 (0.68) ml/kg/min versus in the second CPET was 26.62 (0.69) (P = 0.015). A significant increase was observed in the body weigh 64.98 (1.13) versus 66.55 (1.17) (P = 0.001). No significant differences were observed in terms of EP. Comparing the first with the second CPET, the mean exercise time was 12.75 min (3.11) versus 12.46 min (2.62) (P = 0.420); the mean maximal velocity was 6.2 km/h (0.8) versus 6.1 km/h (0.8) (P = 0.114); and the maximum % grade was 11.45% (0.11) versus 11.62% (0.09) (P = 0.159). CONCLUSIONS: The results suggest that despite observed decline in VO2Peak and an increase in the body weight the EP (duration of exercise time, velocity and percentage of grade) has been maintained without a deterioration along the time, sign of favorable evolution of the CHD in adults. More research is needed to find the reason why the EP does not correspond to the AC. Supported by SUR of DEC Generalitat de Catalunya and European Union 2020FI_B200128.

ANTHROPOLOGICAL, HEMATOLOGICAL AND CARDIO-PHYSIOLOGICAL VARIABLES IN PHYSICALLY ACTIVE BOYS AND GIRLS

Physical activity (PA) is stimulatory physiologic stress for the human body and regular PA induces significant changes in many physiological, biochemical and anthropological parameters. The aim of this study is to determine the values and the differences among the cardio-physiological, hematological and anthropological parameters for different age and gender subgroups in healthy physically active children and an adolescent population. An anthropometric evaluation (Matiegka protocol), hematological analysis i.e., red blood cells count (RBC), hemoglobin level, hematocrit, and ergometrical testing (Brus protocol) were made. Regarding mass and height until the age of 12 (U12), girls were heavier and taller than boys. The mean values for relative muscle mass in all the groups of boys and girls of different ages are in the optimal range (>50%) and indicate well developed muscle mass. There are no differences between the same age subgroups for this anthropometric parameter between the boys and girls. All the subgroups of girls of different ages showed higher body fat percent than their male siblings. Among the girls, RBC variables did not show a difference in the age subgroups. Regarding gender, all RBC variables were significantly higher among the male groups, except the U12. Cardio-physiological parameters of heart frequency at rest, exercise time duration and maximal oxygen consumption (VO2max), were significantly higher among the boys. In all age-based male subgroups VO2max was higher among the older boys. Conclusion: This study has shown age related changes in anthropological, hematological and ergometrical parameters in a male and female young active population. The girls showed significantly lower levels of cardio-physiological fitness which can be contributed either to gender and lower volume of PA.

EFFECTS OF VARIOUS HYPOBARIC HYPOXIA ON METABOLIC RESPONSE, SKELETAL MUSCLE OXYGENATION, AND EXERCISE PERFORMANCE IN HEALTHY MALES

Objective This study aimed to evaluate the effect of various levels of hypoxia versus normoxia on exercise perfor-mance, measured by metabolic parameters and skeletal muscle oxygenation profiles during graded exercise test (GXT) in healthy men. Methods In this randomized crossover trial, 11 healthy male participants (age 21.5 ± 2.3 years) performed the GXT using a cycle ergometer at sea-level (760 torr) and at various hypobaric hypoxia: 633, 526, and 433 torr, corresponding to simulated altitudes of 1500, 3000, and 4500 m, respectively. The GXT was started at 50 W and increased by 25 W every 2 min until the participants were exhausted. The pedal frequency was set to 60 rpm. Metabolic parameters (heart rate, HR; minute ventilation, VE; carbon dioxide excretion, VCO2; respiratory exchange ratio, RER; peripheral capillary saturation, SpO2; oxygen consumption, VO2; and blood lactate, O2 pulse) and skeletal muscle oxygen profiles (oxygenated hemoglobin and myoglobin, OxyHb; deoxygenated hemoglobin and myoglobin, DeoxyHb; and tissue oxygen saturation, StO2) were measured for every 2 min during the GXT. Exercise performance was evaluated by maximal oxygen con-sumption, peak power, and duration of exercise time obtained through GXT. Results Regarding metabolic parameters, HR (P < 0.05), VE, (P < 0.05), VCO2 (P < 0.05), RER (P < 0.05), and blood lactate (P < 0.05) showed significant increase under hypoxia compared to normoxia. Moreover, the increase was more pronounced as hypoxia became more severe. However, the SPO2 (P < 0.05) and O2 pulse (P < 0.05) presented a significant decrease under hypoxia compared to normoxia. Similarly, the decrease was more pronounced as hypoxia became more severe. VO2 (P > 0.05) did not show significant difference under different environmental conditions. In skeletal muscle oxygen profiles, none of the param-eters showed noticeable changes. Regarding exercise performance, VO2max (P < 0.05) and exercise time (P < 0.05) decreased significantly as hypoxia became more severe, and peak power (P < 0.05) decreased significantly at simulated altitudes of 3000 and 4500 m compared to normoxia. Conclusion A decrease in exercise performance is due to a decrease in metabolic function under various hypoxia compared to normoxia and the decrease was more pronounced as hypoxia became more severe.

The role of skeletal muscle contractile duration throughout the whole day: reducing sedentary time and promoting universal physical activity in all people.

A shared goal of many researchers has been to discover how to improve health and prevent disease, through safely replacing a large amount of daily sedentary time with physical activity in everyone, regardless of age and current health status. This involves contrasting how different muscle contractile activity patterns regulate the underlying molecular and physiological responses impacting health‐related processes. It also requires an equal attention to behavioural feasibility studies in extremely unfit and sedentary people. A sound scientific principle is that the body is constantly sensing and responding to changes in skeletal muscle metabolism induced by contractile activity. Because of that, the rapid time course of health‐related responses to physical inactivity/activity patterns are caused in large part directly because of the variable amounts of muscle inactivity/activity throughout the day. However, traditional modes and doses of exercise fall far short of replacing most of the sedentary time in the modern lifestyle, because both the weekly frequency and the weekly duration of exercise time are an order of magnitude less than those for people sitting inactive. This can explain why high amounts of sedentary time produce distinct metabolic and cardiovascular responses through inactivity physiology that are not sufficiently prevented by low doses of exercise. For these reasons, we hypothesize that maintaining a high metabolic rate over the majority of the day, through safe and sustainable types of muscular activity, will be the optimal way to create a healthy active lifestyle over the whole lifespan.

Relationship between exercise induced elevation of left ventricular filling pressure and exercise intolerance in patients with atrial fibrillation.

BackgroundElevated left ventricular filling pressure (LVFP) is an important cause of exercise intolerance in patients with atrial fibrillation (AF). Exercise stress echocardiography could assess LVFP during exercise. The objective of this study was to investigate the relationship between exercise induced elevation of LVFP and exercise capacity in patients with AF.MethodsThis study included 145 consecutive patients (81 men and 64 women; mean age 65.5 ± 8.0 years) with persistent non-valvular AF and normal left ventricular systolic function (left ventricular ejection fraction ≥ 50%). All patients underwent a symptom-limited cardiopulmonary exercise test (CPET). Doppler echocardiography was performed both at rest and immediately after exercise. Five consecutive measurements of early diastolic mitral inflow velocity (E) and early diastolic mitral annular velocity (e') were taken and averaged. E/e' ratio was calculated. Elevated LVFP was defined as E/e' > 9, and patients with elevated LVFP at rest were excluded.ResultsPatients were classified into two groups according to LVFP estimated by E/e' ratio after exercise: 39 (26.9%) with elevated LVFP after exercise and 106 (73.1%) with normal LVFP. As compared with patients with normal LVFP, the ones with elevated LVFP after exercise had significantly lower peak oxygen uptake (VO2 peak) (21.7 ± 2.3 vs. 26.4 ± 3.8 mL/min per kilogram, P < 0.001), lower anaerobic threshold (19.9 ± 2.5 vs. 26.0 ± 4.0 mL/min per kilogram, P < 0.001), and shorter exercise time duration (6.2 ± 0.8 vs. 7.0 ± 1.3 min, P < 0.001). Multivariate analysis showed that age, gender and E/e' after exercise were significantly correlated with VO2 peak.ConclusionElevated LVFP estimated by E/e' ratio after exercise is independently associated with reduced exercise capacity in AF patients.

Relationship between E/Em ratio and exercise capacity in patients with atrial fibrillation

To explore the relationship between the ratio of early diastolic transmitral velocity to early diastolic mitral annular velocity (E/Em) and exercise capacity in patients with atrial fibrillation. A total of 94 consecutive patients with non-valvular atrial fibrillation and preserved left ventricular ejection fraction admitted into our department from December 2011 to June 2013 were included. Echocardiography and cardiopulmonary exercise test were performed. According to E/Em, they were divided into two groups of normal E/Em (E/Em ≤ 9) and elevated E/Em (E/Em>9). The parameters of exercise capacity, including VO2max/kg, anaerobic threshold/kg (AT/kg) and exercise time duration were compared between two groups. And the determinants of VO2max/kg were identified by multivariate regression analysis. The number of patients was 57(60.6%) with normal E/Em and 37 (39.4%) with elevated E/Em. As compared to those with normal E/Em, the patients with elevated E/Em had lower VO₂max/kg [(26 ± 4) vs (20 ± 4) ml × min⁻¹ × kg⁻¹, P < 0.001], lower AT/kg [(25 ± 4) vs (19 ± 5) ml ×min⁻¹ × kg⁻¹, P < 0.001] and shorter exercise time duration [(7.2 ± 1.3) vs (5.8 ± 1.3) min, P < 0.001]. Multivariate regression analysis revealed that three significant variables were independently associated with VO₂max/kg: age (r = -0.412, P < 0.001), gender ((25 ± 5) and (21 ± 4) ml × min⁻¹ × kg⁻¹ for males and females separately, P < 0.001) and E/Em (r = -0.535, P < 0.001). E/Em was independently associated with exercise capacity in patients with atrial fibrillation.

The Metabolic Costs of Reciprocal Supersets vs. Traditional Resistance Exercise in Young Recreationally Active Adults

An acute bout of traditional resistance training (TRAD) increases energy expenditure (EE) both during exercise and in the postexercise period. Reciprocal supersets (SUPERs) are a method of resistance training that alternates multiple sets of high-intensity agonist-antagonist muscle groups with limited recovery. The purpose of this study was to compare the energy cost of SUPERs and TRAD both during and in the postexercise period. We hypothesized that SUPERs would produce greater exercise EE relative to the duration of exercise time and greater excess postexercise oxygen consumption (EPOC) than TRAD of matched work. Ten recreationally active, young men each participated in 2 exercise protocols: SUPER, followed 1 week later by TRAD matched within using a 10-repetition maximum load for 6 exercises, 4 sets, and repetitions. Participants were measured for oxygen consumption and blood lactate concentration during exercise and 60 minutes postexercise after each exercise bout. No significant differences were observed in aerobic exercise EE between trials (SUPER 1,009.99 +/- 71.42 kJ; TRAD 954.49 +/- 83.31 kJ); however, when expressed relative to time, the exercise EE was significantly greater during SUPER (34.70 +/- 2.97 kJ.min) than TRAD (26.28 +/- 2.43 kJ.min). Excess postexercise oxygen consumption was significantly greater after SUPER (79.36 +/- 7.49 kJ) over TRAD (59.67 +/- 8.37 kJ). Average blood lactate measures were significantly greater during SUPER (5.1 +/- 0.9 mmol.L) than during TRAD (3.8 +/- 0.6 mmol.L). Reciprocal supersets produced greater exercise kJ.min, blood lactate, and EPOC than did TRAD. Incorporating this method of resistance exercise may benefit exercisers attempting to increase EE and have a fixed exercise volume with limited exercise time available.

Exercise-induced asthma screening of elite athletes: field versus laboratory exercise challenge.

The purpose of this study was to compare a laboratory based exercise challenge (LBC) to a field based exercise challenge (FBC) for pulmonary function test (PFT) exercise-induced asthma (EIA) screening of elite athletes. Twenty-three elite cold weather athletes (14 men, 9 women) PFT positive for EIA (FBC screened) served as subjects. Twenty-three gender and sport matched controls (nonasthmatics) were randomly selected to establish PFT reference values for normal elite athletes. Before FBC, athletes completed a medical history questionnaire for EIA symptoms. FBC evaluations consisted of baseline spirometry, actual or simulated competition, and 5, 10, and 15 min postexercise spirometry. PFT positive athletes were evaluated in the laboratory using an exercise challenge simulating race intensity (ambient conditions: 21 degrees C, 60% relative humidity). PFT procedures were identical to FBC. 91% of PFT positive and 48% of PFT normal athletes reported at least one symptom of EIA, with postrace cough most frequent. Baseline spirometry was the same for PFT positives and normal controls. Lower limit reference range (MN - 2 SD) of FEV1 for controls suggests that postexercise decrements of greater than approximately -7% indicate abnormal airway response in this population. Exercise time duration did not effect bronchial reactivity; 78% of FBC PFT positives were PFT normal post-LBC. Self-reported symptoms by elite athletes are not reliable in identifying EIA. Reference range criterion for FEV1 decrement in the elite athlete postexercise contrasts current recommended guidelines. Moreover, a large number of false negatives may occur in this population if EIA screening is performed with inadequate exercise and environmental stress.

A New Transmucosal Therapeutic System: Overview of Formulation Development and in Vitro/in Vivo Clinical Performance

A new transmucosal therapeutic system (TmTs) was developed for controlled systemic delivery of drugs, which are labile to hepatic “first-pass” metabolism, through oral mucosa. It consists of a fast-release layer, which provides a rapid release of drug for prompt rise in blood drug concentration to reach the therapeutic level, and a sustained-release layer, which releases the drug continuously for sustained duration to maintain the therapeutic level for up to 12 hrs. The sustained-release layer also contains mucoadhesive composition, so TmTs can be applied on gingival mucosa for continuous transmucosal controlled administration of drugs. Using isosorbide dinitrate (ISDN), a well-known antianginal drug which is known to be subjected to extensive presystemic elimination when taken orally, the systemic bioavailability has been improved by 37 fold in beagle dogs and by almost 5 fold in humans compared to that of marketed oral sustained-release tablet and the plasma concentration profile has also been prolonged to 12 hrs from less than 1 hr for marketed sublingual tablet and spray products in both beagle dogs and in human volunteers. Multi-fractional absorption model has been successfully applied for pharmacokinetic analysis, which demonstrates that the rate-limiting step for the transmucosal systemic delivery is the release of ISDN from the TmTs. Clinical studies performed in the anginal patients for up to one year have demonstrated the therapeutic benefits of this TmTs in achieving a substantial reduction in the frequency of anginal attacks and prolongation in the duration of exercise time.

Alterations in myocardial perfusion during exercise after isosorbide dinitrate infusion in patients with coronary disease: Assessment by thallium-201 scintigraphy

We studied the effect of intravenous isosorbide dinitrate (ISDN) on myocardial perfusion of patients with coronary artery disease, by using exercise thallium-201 (TI-201) myocardial scintigraphy. A control study was conducted initially to assess regional myocardial perfusion rate. Left ventricular myocardium was divided into six parts: anterior, lateral, apical, inferior, posterior, and septal segments. The segmental myocardial perfusion was characterized according to TI-201 initial uptake index (IUI) of relative distribution and redistribution index (RDI) of TI-201 washout. The normal limit of IUI and RDI was established from the data of 17 persons with normal coronary arteries, and then the IUI ≤ 84% and the RDI ≥ 1.12 was defined as abnormal. Based on IUI and RDI, each segment was characterized into three types: A type = IUI ≦ 84%, RDI ≧ 1.12; B type = IUI ≦ 84%, RDI < 1.12; and C type = IUI > 84%, RDI < 1.12. ISDN was given as a dose of 0.1 mg/kg/hr, and then treadmill testing was repeated for the same duration of exercise time using the same protocol as in the control period. The segments of A type showed a significant improvement in IUI and RDI after receiving ISDN infusion, while the B and C type segments showed no change. It was also shown that the improvement of IUI and RDI of the A type segments was not as marked in multivessel disease as in cases of single-vessel disease. The results of our study suggest that ISDN particularly improves myocardial perfusion in ischemic myocardium, and the degree of improvement is influenced by myocardial viability and the severity of coronary artery disease.