Fitness in the fit: does physical conditioning affect cardiovascular risk factors in middle-aged marathon runners?

OBJECTIVE: The study was designed to assess cardiovascular risk factorsin marathon runners with different degrees of fitness. DESIGN: A total of 30 male middle-aged marathon runners were dividedaccording to their marathon running time into fit (265 ±8 min), fitter (222 ± 5 min) and fittest (178 ±12 min). The three groups of 10 runners each were comparablein age, weight, and body surface area. Cardiovascular risk factorswere assessed by measuring arterial pressure before and duringexercise (150 watts) and determination of plasma lipoproteins,uric acid, glucose and white blood cell count before and aftera marathon run. RESULTS: All measured laboratory values such as high-density lipoproteincholesterol (P<0.05), low-density lipoprotein cholesterol(P <0.05), total cholesterol (non-significant), triglycerides(non-significant), blood sugar (non-significant), uric acid(P <0.05), and white blood cell count (P <0.05) indicateda lower cardiovascular risk in the fastest when compared withthe slowest runners. Resting blood pressure was similar in thethree groups but consistently lower at all levels of exercisein the fittest when compared with the less fit runners. Thefittest runners also showed greater increases in high-densitylipoprotein cholesterol after the marathon run (14% vs 8% inthe slowest runners, P<0.05). CONCLUSIONS: We conclude that even at the extreme end of a continuum suchas represented by well-conditioned, middle-aged marathon runners,cardiovascular risk factors are related to the degree of fitness,as measured by the marathon running time.     

Functional factors that are important correlates to physical activity in people with multiple sclerosis: a pilot study

Purpose: Identify functional factors that are important correlates to physical activity levels among people with multiple sclerosis.

Methods: A total of eight functional tests were conducted and physical activity was objectively measured (Actigraph GT3X accelerometer) for one week in 34 people with multiple sclerosis. A corrected Akaike Information Criterion analysis was performed to identify the strongest correlates with moderate-to-vigorous physical activity, total activity and sedentary time.

Results: The multiple regression analysis converged on a model for moderate-to-vigorous physical activity (R²?=?0.31, F?=?6.97, p=?0.003) that included total strength of the less-affected leg (partial r?=?0.46, p?=?0.007) and average peg test performance (partial r?=??0.30, p?=?0.087). The model for total activity (R²?=?0.40, F?=?10.51, p?<?0.001) included five times sit-to-stand performance (partial r=??0.44, p?=?0.010) and total strength of the less-affected leg (partial r?=?0.31, p?=?0.077). The model for sedentary time (R²=0.22, F?=?9.23, p?=?0.005) only included total strength of the more affected leg (r=??0.47, p?=?0.005).

Conclusion: These results suggest that leg strength, manual dexterity and the ability to perform functional tasks may be important correlates with physical activity levels in people with multiple sclerosis. The findings of this pilot study can inform future investigations aiming to increase physical activity levels or develop improved rehabilitation protocols for people with multiple sclerosis.

• Implications for Rehabilitation

• Physical activity is an effective means of improving the symptoms associated with multiple sclerosis.

• Participation in physical activity by people with multiple sclerosis may be affected by functional factors such as leg strength, manual dexterity and the ability to rise from a seated position.

• Bilateral leg strength differences should be assessed and addressed in people with multiple sclerosis.

     

Comparison of the antihypertensive effects of carvedilol and metoprolol on resting and exercise blood pressure

The present study was conducted to assess the efficacy and safety of carvedilol 50 mg as compared to metoprolol 200 mg at rest and during and after a standardized bicycle ergometric exercise test. Carvedilol is a novel non-selective -blocker without intrinsic sympathomimetic activity possessing vasodilatory properties primarily due to an ₁-antagonism in the same dose range. Both drugs were effective in reducing systolic and diastolic blood pressure at rest and during and after exercise. The reduction of diastolic blood pressure was much stronger under carvedilol treatment than under metoprolol treatment at all measurement points. Carvedilol was even effective in the treatment of patients whose blood pressure was unsatisfactorily controlled by metoprolol. This shows the importance of the vasodilation component of carvedilol. No serious adverse events were observed. Carvedilol therefore promises very well as a powerful and safe drug for the treatment of essential arterial hypertension.     

Preserved ventricular pump function after a marked reduction of left ventricular mass.

OBJECTIVES. This study was designed to evaluate the long-term effects of combination therapy with an angiotensin-converting enzyme inhibitor and a beta-adrenergic blocking agent on the relation between the decrease in arterial pressure at rest and during exercise and the decrease in left ventricular mass. BACKGROUND. A variety of antihypertensive drugs including angiotensin-converting enzyme inhibitors and beta-blockers have been shown to reduce ventricular hypertrophy, although little is known about combination therapy and the time course of such a reduction. METHODS. Twenty-one patients with previously untreated essential hypertension were treated with a low dose combination of 50 mg of atenolol and 10 mg of enalapril once daily for 39 months. Cardiovascular findings were assessed by two-dimensionally guided M-mode echocardiography in the pretreatment phase and after 6 and 39 months of combination therapy. RESULTS. Combination therapy reduced arterial pressure at rest from 161/108 to 130/86 mm Hg (p less than 0.001) and exercise arterial pressure at 100 W from 192/112 to 167/95 mm Hg (p less than 0.001). After 6 months of treatment, significant decreases in interventricular septal thickness (9%, p less than 0.001), posterior wall thickness (9%, p less than 0.001) and left ventricular mass index (16%, p less than 0.001) were demonstrated on the echocardiogram. After 39 months of therapy, reductions in these values were 28% (p less than 0.001), 29% (p less than 0.001) and 40% (p less than 0.001), respectively. CONCLUSIONS. Long-term treatment with combination therapy of atenolol and enalapril produced significant reductions in arterial pressure at rest and during exercise accompanied by a marked reduction of left ventricular mass. However, whereas arterial pressure decreased immediately and remained unchanged, left ventricular mass decreased more gradually and continued to decrease throughout the treatment period of greater than 3 years. Despite this marked reduction in left ventricular mass, left ventricular pump function was well preserved during rest and exercise.     

Hypertension: left ventricular hypertrophy, ventricular ectopy, and sudden death.

Left ventricular hypertrophy (LVH) has been identified as a significant risk factor for future cardiovascular morbidity and mortality. LVH and its sequelae such as myocardial ischemia, impaired filling and contractility, ventricular arrhythmias, and congestive heart failure can be reduced by specific antihypertensive agents. Future clinical trials will determine whether a reduction of LVH will ultimately improve its inherent ominous prognosis.     

Two years of regular exercise decreases blood pressure and improves motor skills in early childhood

Purpose

Today’s children experience an increasing deficiency in physical activity accompanied by increasing evidence of cardiovascular risk factors such as overweight and elevated blood pressure. Therefore, 3-year-old children were included in a controlled prospective study to assess the efficacy of a preventive regular exercise program on blood pressure (BP) regulation and motor skills.

Methods

160 children (INT) in 17 nursery schools participated in a regular exercise program. 105 comparable individuals served as controls (CON). BP was measured at rest and during standardized ergometric exercise. Motor testing included jumping, running, and balance skills.

Results

Prior to intervention, both groups were comparable in all measurements. After 2 years, both groups improved in all tests with significant differences between the two groups. Diastolic BP (dBP) was significantly lower in INT when compared with CON at rest and during standardized exercise (62?±?11 vs. 68.8?±?11 mmHg). After 2 years, dBP decreased during exercise in INT when compared with dBP at rest. In contrast, there was an increase in dBP during exercise in CON. INT came off better in balance (195 vs. 139 cm; p?<?0.001), jumping (103.9 vs. 83.7 cm; p?<?0.001), and 6-m running (2.2 vs. 2.62 s; p?<?0.001).

Conclusions

In very young children, 2 years of regular exercise had beneficial effects on BP at rest and BP regulation during exercise and motor skills. Therefore, children should be encouraged to exercise regularly to prevent cardiovascular risk factors such as arterial hypertension and morbidity and mortality in later life.

     

Effectiveness of a physical activity intervention in preschoolers: A cluster‐randomized controlled trial

Several activity interventions in preschool settings exist, but little attention has been paid to effects on hemodynamic factors. The study aimed to assess the effectiveness of an exercise program on health‐related outcomes including blood pressure (BP) and markers of vascular function in preschoolers, with focus on socioeconomic background. This study is a cluster‐randomized controlled trial, with preschool as unit of randomization and children as unit of analysis. Preschools with 3‐ to 6‐year‐old children, stratified by social area, were randomly allocated to: intervention (three clusters, n = 92) including 2 d·wk^?1/45 min (6 months) exercise lessons or control (two clusters, n = 43). In total, 135 children (4.8 ± 0.8 y) had minimum one outcome measurement at baseline and follow‐up. Primary outcome: peripheral BP. Secondary outcomes: central BP, pulse wave velocity (PWV), BMI, waist circumference, physical activity measures, motor skills. Maternal education was used as an indicator of socioeconomic status. Mixed models were applied to evaluate differences in mean change. Group allocation had no effect on primary or secondary outcomes. However, the intervention was effective in reducing increases in peripheral systolic BP (?3.4 mm Hg; 95% CI: ?6.6; ?0.2; P = 0.037), central systolic BP (?3.8 mm Hg; ?6.4; ?1.1; P = 0.006), and PWV (?0.1 m/s; ?0.2; ?0.0; P = 0.045) among children whose mothers had the lowest educational level. We found no evidence for effectiveness of a 6‐months preschool‐based exercise program on hemodynamics, anthropometrics, activity, or motor skills, but lack of process evaluations and poor fidelity preclude interpretation of the causal relation. However, the results indicate that children from lower social backgrounds could benefit from early exercise‐promoting interventions.     

FDG‐PET detects nonuniform muscle activity in the lower body during human gait

Introduction: Nonuniform muscle activity has been partially explained by anatomically defined neuromuscular compartments. The purpose of this study was to investigate the uniformity of skeletal muscle activity during walking. Methods: Eight participants walked at a self‐selected speed, and muscle activity was quantified using [¹⁸F]‐fluorodeoxyglucose positron emission tomography imaging. Seventeen muscles were divided into 10 equal length sections, and within muscle activity was compared. Results: Nonuniform activity was detected in 12 of 17 muscles (? > 4.074; P < 0.046), which included both uni‐ and multi‐articular muscles. Greater proximal activity was detected in 6 muscles (P < 0.049), and greater distal versus medial activity was found in the iliopsoas (P < 0.042). Conclusions: Nonuniform muscle activity is likely related to recruitment of motor units located within separate neuromuscular compartments. These findings indicate that neuromuscular compartments are recruited selectively to allow for efficient energy transfer, and these patterns may be task‐dependent. Muscle Nerve 54 : 959–966, 2016     

Regular exercise as an effective approach in antihypertensive therapy

PURPOSE: Exercise has been well documented to exert a beneficial effect on cardiovascular health. The effective control of arterial pressure (BP) is essential from the standpoint of cardiovascular prevention. So far, no study has determined the long-term effect of regular training as a monotherapy on both BP at rest and during exercise. METHODS: Therefore, 10 subjects with hypertension (aged 43 +/- 3 yr) were studied in order to define BP response to long-term aerobic training. BP measurements were obtained at rest and during ergometry (50-100 W). Patients were instructed to exercise weekly (2 x 60 min aerobic exercise). RESULTS: BP during exercise (100 W) did fall already after 6 months of regular training from 184 +/- 10/107 +/- 6 to 170 +/- 10/100 +/- 7, and this was associated with a 14% decrease in the rate-pressure product (at 100 W). After 18 months of training, there were further reductions in BP, at rest from 139 +/- 9/96 +/- 6 to 133 +/- 14/91 +/- 7 (P < 0.05) and during ergometry (100 W) from 184 +/- 10/107 +/- 6 to 172 +/- 8/96 +/- 6 mm Hg (P < 0.001). During a 3-yr follow-up, BP continued to decrease significantly to 130 +/- 13/87 +/- 7 mm Hg at rest and 167 +/- 9/92 +/- 6 mm Hg during exercise. No significant changes in body weight were documented during the training period. CONCLUSION: The data demonstrate that long-term aerobic exercise is associated with a decrease in BP at rest and during exercise, which is comparable to that of drug therapies. This antihypertensive effect of regular training can be maintained as long as 3 yr.     

Depressed systolic and diastolic cardiac function after prolonged aerobic exercise in healthy subjects.

We studied 11 healthy untrained volunteers (aged 28.9 +/- 4.6 years) during 60 minutes of aerobic ergometric exercise with constant heart rates of 130 to 140 beats/minute. We found a continuous and significant decrease in systolic and diastolic pressure from 175 +/- 18/77 +/- 7 mmHg in the 5th minute to 144 +/- 14/68 +/- 6 mmHg in the 60th minute of exercise. Cardiac function and structure were assessed by M-mode echocardiography before exercise, after 5 minutes and after 60 minutes of exercise at comparable heart rates. The results demonstrated significant decreases in cardiac output, ejection fraction, and diastolic posterior wall velocity and an increase in total peripheral resistance after 60 minutes of exercise. We conclude that the decrease in blood pressure during long-term aerobic exercise in healthy untrained subjects might be at least influenced by a decrease in left ventricular filling and contractility, possibly indicating cardiac fatigue.