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BACKGROUND/OBJECTIVES: Moderate, long-term weight loss results in the loss of bone mass in overweight or obese premenopausal women. However, whether these changes persist during weight maintenance or regain remains to be determined. SUBJECTS/METHODS: Overweight or obese (body mass index: 25.8-42.5 kg/m(2)) women (n=40) with at least two risk factors for the metabolic syndrome participated in this 12-month study that examined the effects of prescribed weight loss and regain, with or without exercise, on bone turnover and on bone mineral density (BMD) in a subset of participants (n=24). During the first 6 month, participants lost ≈ 10% of their initial body weight via energy restriction and supervised aerobic exercise. Following weight loss, participants were randomly assigned to either an exercise or a no exercise treatment for the regain (+50% of weight lost) phase. A one-way (time) repeated measures one-factor analysis of variance (RMANOVA) tested the effects of weight loss on BMD and bone turnover, and a two-way RMANOVA (time, exercise) was used to examine the effects of exercise during weight regain. RESULTS: Hip (P=0.007) and lumbar spine (P=0.05) BMD decreased with weight loss, and remained reduced after weight regain with or without exercise. Likewise, the weight-loss-associated increases in osteocalcin (P<0.001) and C-terminal peptide of type I collagen (P<0.001) persisted following weight regain, independent of exercise. CONCLUSIONS: The results of the present study, which is the first to examine changes in bone mass and turnover during carefully controlled weight regain, suggest that weight-loss-induced perturbations in bone mass and turnover persist after partial weight regain, regardless of whether regular weight-bearing aerobic exercise was continued.

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The purpose of this study was to evaluate the effect of medium-chain triglycerides (MCT) with and without exercise on postprandial lipemia (PPL). Subjects were 25 young men and women. Each subject performed three trials: 1) control (fat meal only, 1.5 g fat/kg) 2) MCT (substitution of MCT oil, 30% of fat calories), and 3) MCT + Ex (exercise 12 h before the MCT meal). Before each trial, the subject underwent consistent dietary preparation. Blood was collected on 2 separate days for baseline measurements of postheparin lipases and, in each trial, at 0 h (premeal), at 2, 4, 6, and 8 h after the fat meal for triglycerides and cholesterol ester transfer protein (CETP), and at 8 h for postheparin lipoprotein lipase (LPL) and hepatic lipase activities (HL). ANOVA indicated that the partial substitution of MCT oil to the fat meal did not affect the PPL response. However, the PPL was significantly lower after the MCT + Ex trial vs. the other trials. LPL activity was significantly elevated after all trials compared with baseline, whereas HL was lower in the MCT + Ex trial only. CETP mass was significantly lower at 4 and 8 h than 0 h during all trials but relatively higher in the MCT + Ex trial vs. the nonexercise trials. These results suggest that MCT does not affect the TG response to a fat meal. LPL and CETP are affected by a fat meal with or without exercise, but HL is affected only when exercise is included.

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Because n-3 fatty acid ingestion and aerobic exercise each has been associated with diminished postprandial lipemia (PPL), the purpose of this study was to evaluate the effect of a combination of these two factors on PPL. Sedentary men underwent a standard dietary preparation, including a 12-h fast before each trial. Six subjects performed a control trial (fat meal, 100 g fat) and an n-3 fatty acid trial (fat meal after 3 wk of n-3 fatty acid supplementation at 4 g/day). In a parallel experiment, six different subjects underwent a control trial and n-3 fatty acid supplementation + 60 min of exercise before ingestion of the fat meal. Supplementation with n-3 fatty acid significantly decreased baseline triglyceride (TG) concentrations but did not significantly affect PPL. The combination of n-3 fatty acid and exercise had no effect on the postprandial TG response. The present study suggests that n-3 fatty acid supplementation lowers resting TG concentrations but inhibits the beneficial effect of aerobic exercise on the postprandial TG response.

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The purpose of the study was to examine the effect of exercise timing on postprandial lipemia responses. Subjects were 21 recreationally trained men (ages 27 +/- 1.7 yr). Each subject performed four trials: 1) Control (fat meal only), 2) Post (exercise 1 h after a fat meal), 3) 1 h-Pre (exercise 1 h before a fat meal), and 4) 12 h-Pre (exercise 12 h before a fat meal). In each trial, subjects had a standard fat meal to induce postprandial hypertriglyceridemia. Blood samples were taken at 0 h (immediately before the fat meal) and at 2, 4, 6, 8, and 24 h after the meal. In the exercise trials, each subject exercised at 60% of maximal O2 consumption for 1 h. The results indicated that triglyceride area under the curve scores in premeal-exercise trials were lower (P < 0. 05) than those in Post and Control. At 24 h, total high-density lipoprotein (HDL)-cholesterol in the premeal-exercise trials was higher (P < 0.05) than that at 0 h, whereas total HDL-cholesterol was not changed in Control and Post. At 24 h, HDL subtype 2-cholesterol was higher (P < 0.05) in the premeal-exercise trials than in Control, which did not differ from Post. These results suggest that exercising before a fat meal may have a beneficial effect on the triglyceride response and HDL metabolism, which may blunt atherosclerotic process induced by the fat meal.

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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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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.

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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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The purpose of this study was to examine differences in postprandial hypertriglyceridemia (PP-HTG) and low density lipoprotein (LDL) subfraction distribution among groups of men and women with different fitness levels. Fifty-four men and women (ages 30-53 yr) were recruited based on their previous two-year activity level: sedentary (S), recreational exercisers (R), and endurance trained (T). After a 24-h dietary preparation, blood was collected, and LDL subfractions were separated and analyzed for cholesterol (C) and apoprotein B100. Plasma triglyceride (TG) concentration was assessed before and at 2, 4, 6, and 8 h after fat meal. PP-HTG was significantly higher for the S group compared with the two activity groups. LDL3-C and LDL3-apoprotein B100 were significantly higher for the S group compared with the T group and for men compared with women. These findings suggest that both recreational and competitive aerobic training are associated with a lower TG response after a fatty meal. However, higher volume aerobic training may be necessary to reduce the number of dense LDL molecules and their cholesterol content.

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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.

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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.

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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.

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The resting metabolic rate (RMR) following recovery from level jogging, which includes an eccentric component, was hypothesized to be greater and remain elevated longer than following concentric cycling due to repair of exercise-induced muscle damage. Nine males participated in both a jogging and cycling protocol. RMR measurements were determined by indirect calorimetry before and on the seven mornings following three consecutive days of 45-min exercise sessions performed at equal energy expenditures. Daily protein intake and urinary nitrogen (N) output were measured throughout both protocols. No differences were observed in the resting oxygen consumption, respiratory exchange ratio, or heart rate between baseline measurements and from any of the postexercise days following the third exercise bout. Urinary N and the estimated N balance during postexercise also did not change from baseline values over time or mode x time. However, the overall estimated N balance for the jogging protocol was less positive than for the cycling protocol (p < 0.05). Muscular soreness was greater (p < 0.05) and lasted longer from the jogging protocol. Although, muscle damage may have been more severe in the jogging protocol, RMR and N balance were not different between the two exercise modes.

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In order to determine whether exercise mode affects recovery energy expenditure, 7 active men (average age 25 yrs) performed a control rest and three submaximal exercise bouts in counterbalanced order in separate weeks. The bouts, designed to involve three levels of eccentric muscular activity, included 60% VO2max jog (60 J), 60% downhill (-5%) jog (60 DH), 60% cycling (60 C), and a control session. Following a 24-hr period of regulated activity and diet, subjects exercised for 60 min. VO2 and RER were assessed during 48 hrs of regulated recovery. Total energy use was elevated following 60 C and 60 DH versus control, and fat energy use was elevated following 60 J, 60 DH, and 60 C versus control. For combined trials, the total energy use was higher at 1, 2, and 9 hrs postexercise. These results do not support the hypothesis that eccentric muscular activity affects the magnitude of recovery energy expenditure.

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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.

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Investigations on resting and recovery metabolism have used both preexercise and separate control-day measurements as a baseline for comparisons. The purpose of this study was to compare preexercise resting data with nonexercise control-day resting data. Seven active men aged 25 +/- 5 y and weighing 83.2 +/- 15.4 kg followed prescribed dietary (12-h fast) and activity (48-h abstinence) preparatory protocols and were scheduled to exercise for 60 min on three separate occasions. A fourth session involved no exercise (control) and included an extended rest period. Resting metabolic rate (RMR) and heart rate measured in a semirecumbent position were not significantly different among preexercise and control conditions. Respiratory exchange ratio (RER) increased as the control rest was extended to 120 min. Reliabilities for both RMR and RER were initially high but were decreased at the end of the extended rest. These results suggest that preexercise RMR data can be used as a baseline for comparison purposes. In addition, prolonging the rest period does not appear to improve the RMR or RER values.

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To compare the cardiovascular and metabolic responses to different exercise modes, ten healthy, elderly men (aged 71.4 +/- 4.2 yr) walked and cycled in the low-sit position for 15 min each at 70% of peak heart rate. Fifteen minutes of recovery separated the exercise bouts. Analysis of expired air was used to calculate oxygen consumption (VO2), respiratory exchange ratio (RER), O2 pulse, total energy expenditure (TE) and fat oxidation (FO). Ratings of perceived exertion (RPE) were recorded for both legs and breathing. Each subject maintained similar heart rates on each of the exercise bouts (mean = 108 beats.min-1). No significant differences were found in VO2, O2 pulse and TE. RPE's were significantly lower during walking than cycling (P < 0.05). FO was 42% higher during walking than cycling (P < 0.05). These results suggest that although the cardiovascular response and TE use during these two modes are similar, elderly men burn more fat during walking than low-sit cycling.

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This paper describes a method for inferring articulatory parameters from acoustics with a neural network trained on paired acoustic and articulatory data. An x-ray microbeam recorded the vertical movements of the lower lip, tongue tip, and tongue dorsum of three speakers saying the English stop consonants in repeated Ce syllables. A neural network was then trained to map from simultaneously recorded acoustic data to the articulatory data. To evaluate learning, acoustics from the training set were passed through the neural network. To evaluate generalization, acoustics from speakers or consonants excluded from the training set were passed through the network. The articulatory trajectories thus inferred were a good fit to the actual movements in both the learning and generalization conditions, as judged by root-mean-square error and correlation. Inferred trajectories were also matched to templates of lower lip, tongue tip, and tongue dorsum release gestures extracted from the original data. This technique correctly recognized from 94.4% to 98.9% of all gestures in the learning and cross-speaker generalization conditions, and 75% of gestures underlying consonants excluded from the training set. In addition, greater regularity was observed for movements of articulators that were critical in the formation of each consonant.

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Twenty novice male weight lifters performed resistance exercises using three different breathing techniques to determine the effects on blood pressure. Systolic and diastolic blood pressures were measured by an automated non-invasive method while subjects performed the single arm curl and double knee extension using the different breathing techniques. Performing the Valsalva manoeuvre (breath-holding) during either the single arm curl or double knee extension produced the highest blood pressure responses. Inhaling during the concentric phase of the exercise was associated with blood pressure elevations that were similar to the elevations observed with exhaling during the concentric phase. The heart rate response was slightly higher with inhalation. These results suggest that performing the Valsalva manoeuvre exaggerates the blood pressure response to resistance exercise. In addition, coupling inhalation with the concentric phase of the lift offers no cardiovascular advantage over coupling exhalation with the concentric phase of the lift.

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