Biomedical subjects

G Ziogas

Publications and source records attributed to G Ziogas.

8 recordsLinked to original sources

PubMed2006

Does the intensity of an exercise programme modulate body composition changes?

Exercise training is a useful component of weight maintenance programmes. Although energy expenditure, not intensity or duration, seems to determine the amount of weight loss attributable to exercise, it is not clear whether changes in the components of body mass are also insensitive to these parameters. Thus, the aim of the present study was to compare the effect of two isoenergetic exercise training programmes, one of low and one of high intensity, on body composition. Fourteen healthy premenopausal untrained women were divided into two equivalent groups, which exercised on treadmill at 45 or 72 % of V(O2max) four times a week for three months, spending 1548 kJ (370 kcal) per exercise session. No dietary intervention was applied. Body mass decreased significantly in both groups but more in the low-intensity than the high-intensity group (by mean +/- SD, 3.3 +/- 1.3 vs. 1.9 +/- 0.9 kg, p = 0.032). The decrease in fat mass was significant in both groups (3.1 +/- 1.2 vs. 2.4 +/- 1.5 kg, respectively) but not significantly different between them. Fat-free mass did not change significantly in either group, although the difference between groups tended to be significant (decrease by 0.2 +/- 0.7 kg in the low-intensity group vs. increase by 0.5 +/- 0.6 kg in the high-intensity group, p = 0.058). In conclusion, exercise training at 45 % of V(O2max) without dietary restriction produced a higher weight loss than at 72 % of V(O2max), whereas the higher intensity tended to maintain fat-free mass, possibly, in part, through the smaller weight loss. Thus, both programmes may prove useful in eliciting favourable changes depending on which target (weight loss or maintenance of fat-free mass) is of higher priority.

Adult↗

PubMed1998

Dietary preparation before rest and exercise testing.

To compare the effectiveness of four dietary preparations for stabilizing resting and exercise measurements, seven male recreational exercisers (27 +/- 4 y) participated in four dietary preparations, each repeated in successive weeks: (1) 24-h random diet including an overnight fast (RAN); (2) 24-h random diet, including fast, followed by a standard meal 3 h before testing (RANM); (3) 24-h prescribed diet including an overnight fast (PRES); and (4) 24-h prescribed diet, including fast, followed by a standard meal (PRESM). After each preparation, metabolic rate (VO2) and respiratory exchange ratio (RER) were measured at rest and in association with moderate treadmill exercise. Plasma was analyzed for glucose, cholesterol, and high-density lipoprotein (HDL)-cholesterol. Repeated measures analyses of variance (ANOVAs) followed by Tukey posthoc tests indicated that resting VO2, RER, and blood parameters were not different between the two trials on the same diet. Exercise RER, however, was slightly different in trial 1 than in trial 2 for all preparations except PRESM. Combining both trials, resting VO2 and exercise RER were higher when a pretesting meal was administered. Plasma values were not different for the four dietary preparations. These results suggest that a standard overnight fast appears to be adequate for establishing representative and reproducible rest and exercise values for the parameters measured, except possibly for exercise RER reliability.

Adult↗

PubMed1997

Influence of fitness status on very-low-density lipoprotein subfractions and lipoprotein(a) in men and women.

The purpose of this study was to examine the influence of the physical activity level of men and women on the very-low-density lipoprotein (VLDL) subfractions and lipoprotein(a) [Lp(a)]. Fifty-four men (n = 30) and women (n = 24) aged 30 to 53 years were recruited based on their level of activity over the past 2 years, and formed three groups: sedentary (S), no routine activity; recreational exercise (R), routine moderate exercise three to five times per week; and trained (T), competition-based, high-volume aerobic training five to seven times per week. Each subject underwent a maximal oxygen consumption (VO2max) test and was measured for body composition (skinfolds) and waist to hip ratio (WHR). Following a prescribed 24-hour diet and abstinence from activity, a blood sample was obtained from each subject and the plasma was analyzed for cholesterol and triglycerides (TGs) in VLDL1, VLDL2, and VLDL3 subfractions. High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and Lp(a) also were analyzed. Total VLDL-C was higher in men than in women, but no gender differences were observed in VLDL subfractions. VLDL1-TG and VLDL2-TG were elevated in the S group compared with groups R and T, even though total VLDL-TG, LDL-C, and HDL-C values were not different among the groups. Values for Lp(a) were not significantly different between men and women or among the groups. The two exercising groups were not different on any lipoprotein variable or WHR. VLDL1-TG was inversely correlated with VO2max and HDL-C. These results suggest that life-style activity is associated with a favorable VLDL subfraction pattern and WHR, but not Lp(a). In addition, long-term recreational activity is associated with a lipoprotein profile and WHR similar to those obtained with higher-volume exercise training.

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PubMed1996

Peak oxygen consumption and ventilatory thresholds on six modes of exercise.

In order to compare responses on six modes of exercise for maximal oxygen consumption (VO2peak) and ventilatory thresholds (VT-1, VT-2), 10 male recreational exercisers (23 +/- 3 yrs) completed incremental maximal tests on treadmill, stationary skier, shuffle skier, stepper, stationary cycle, and rower. After extensive habituation, VO2peak, VT-1, and VT-2 were determined during each maximal bout. A MANOVA followed by ANOVAs, Tukey post hoc tests, and noncentral F tests indicated that the treadmill elicited a significantly higher peak oxygen consumption than did the other modes, and the skier and stepper values were higher than the rower. VO2 at VT-1 was higher on the treadmill than cycle. The treadmill also elicited a higher VO2 at VT-2 than the shuffle skier, cycle, and rower. However, no differences were observed among modes for VT-1 and VT-2 when expressed as a percentage of VO2peak. These results suggest that the treadmill elicits a higher aerobic capacity measure than other modes, but the ventilatory threshold responses (% VO2peak) are similar among modes.

Adult↗

PubMed1995

Physiological and perceived exertion responses to six modes of submaximal exercise.

In order to compare the cardiovascular and perceived exertion responses to 6 modes of exercise, 10 male recreational exercisers were habituated to treadmill jogging, stationary skiing, shuffle skiing, stepping, stationary cycling, and stationary rowing. After following a specific dietary preparation, each participant performed a 20-min exercise bout at a constant 14-rating of perceived exertion (RPE) followed by a second exercise bout at 60% of mode-specific peak oxygen consumption (VO2peak). On the 14-RPE trial, oxygen consumption (VO2) and oxygen pulse were significantly higher during jogging than during other exercise modes, and oxygen pulse was higher during skiing than during shuffle skiing. On the 60% VO2peak bout, oxygen pulse was significantly higher during jogging than during shuffle skiing, cycling and rowing. Ratings of perceived exertion were significantly higher during cycling than during jogging. These results indicated that a variety of exercise modes can be used to develop fitness, but jogging may induce a slightly more favorable VO2-to-RPE relationship.

Adult↗

PubMed1995

%VO2max versus %HRmax regressions for six modes of exercise.

The purpose of the study was to compare the %VO2max versus %HRmax regression equations developed from data collected during incremental work on six exercise modes: treadmill (T), cycle (C), skier (S), shuffle skier (SS), stepper (ST), and rower (R). Ten active males were habituated to all modes and then performed an incremental test to maximum on each mode. Mode order was assigned by Latin square sequences and the tests were separated by at least 72 h. VO2 and HR were recorded at each increment. Regression analyses were performed using SAS-GLM. Regressions for T, S, SS, and ST were not significantly different. C had a lower intercept and higher slope, while R had a higher intercept and lower slope than the other exercise modes. These results suggest that weight bearing exercise modes have similar %VO2max-%HRmax regressions. However, weight supported and arm exercise modes appear to have different regressions.

Adult↗

PubMed1994

Physiological and psychological responses to eccentric exercise.

In order to compare the physiological and psychological responses to various levels of eccentric exercise, 7 active men (25 +/- 5 yrs) exercised for 60 min on separate days at 60% of apparatus specific VO2 max using downhill jogging (-5% 60DH), level jogging (60J), and cycling (60C). Virtually all of the responses to 60DH fell between 60J and 60C. Heart rate, O2 pulse, and respiratory exchange ratio were significantly different among modes, with the responses during 60DH falling between those during 60J and 60C. Fat energy expenditure during the 60-min exercise bout was significantly higher during 60J, followed by 60DH and then 60C. Ratings of perceived exertion followed the order of 60C > 60DH > 60J. Vigor and fatigue scores on the Profile of Mood States also followed a hierarchy that paralleled the physiological responses. These results suggest that downhill jogging elicits physiological and psychological responses that are between those elicited by level jogging and cycling.

Adult↗

PubMedDate not supplied

Influence of activity level on vitamin E status in healthy men and women and cardiac patients.

BACKGROUND: Plasma Vitamin E status may indicate protection against cholesterol oxidation. The purpose of this study was to determine if the plasma vitamin E status is influenced by exercise training status or a single session of submaximal exercise. METHODS: The 41 participants were categorized as sedentary, recreational endurance trained, competitive endurance trained, or cardiac rehabilitation patients. Subjects completed a 3-day dietary record. After a 24-hour diet and exercise control period, including a 12-hour fast, venous blood was collected. Plasma was analyzed for total cholesterol, high-density lipoprotein cholesterol (HDL-C), total lipid, vitamin E, and low-density lipoprotein (LDL) vitamin E concentrations. Each subject then exercised on a treadmill at 60% of measured maximal oxygen consumption for 30 minutes. Postexercise samples were collected 5 minutes after the activity. RESULTS: Multivariate analysis of variance and follow-up Tukey post hoc tests indicated that the cardiac rehabilitation group had lower total fat and monounsaturated fat intake in the diet than the other groups, and the competitive-endurance trained group had higher HDL-C levels. Plasma vitamin E was higher in the cardiac rehabilitation group, but the statistical differences disappeared when expressed per unit of plasma total lipid. The vitamin E content of LDL was not different among the groups. A single exercise session did not alter the plasma lipoprotein or vitamin E status. CONCLUSIONS: These results suggest that habitual activity level of healthy individuals or a single session of exercise does not influence the plasma vitamin E or LDL vitamin E concentrations. However, patients in an endurance cardiac rehabilitation program tend to show normal to elevated plasma vitamin E status.

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