Response of non-insulin-dependent diabetic patients to an intensive program of diet and exercise.

To assess the effectiveness of the Pritikin program of diet and exercise for treating patients with non-insulin-dependent diabetes mellitus (NIDDM), data were obtained from 60 patients who completed the 26-day residential program. Of the 23 patients who were taking oral hypoglycemic agents upon entry, all but 2 were off medication by the end of the program. Of the 17 patients who were taking insulin, all but 4 were off medication at discharge. Two of the four had their insulin reduced by 50% while the remaining two had no major change in their insulin dosage. Fasting blood glucose was reduced from 194.9 +/- 10.1 to 144.6 +/- 7.1 mg/dl. Serum cholesterol was reduced from 225.4 +/- 5.7 to 181.7 +/- 4.9 mg/dl while triglycerides were reduced from 283.7 +/- 28.8 to 186.2 +/- 11.6 mg/dl. The group as a whole lost an average of 4.3 kg/body wt and achieved 40.5% of their desired weight loss. Maximum work capacity increased from 5.6 +/- 0.3 to 7.9 +/- 0.4 METs, while daily walking increased from 11.7 +/- 2.4 to 102.8 +/- 4.8 min/day. The decrease in fasting glucose was not correlated with weight loss (r = 0.24), increase in walking time (r = 0.00), or increase in MET capacity (r = 0.05). We conclude that the total program is an effective means for treating NIDDM patients. We also feel that the high-complex-carbohydrate, high-fiber, low-fat diet is of primary importance.

Effects of cardiac stress during a very-low-calorie diet and exercise program in obese women.

To assess the safety of very-low-calorie diets (VLCDs), stress tests known to induce arrhythmias in susceptible patients were performed in 24 obese women on a VLCD (660-720 kcal/d) for 6 wk. Half of the subjects had diet only (DO) and half underwent supervised exercise (DE) four times weekly. Five control subjects ate a balanced, moderately low-calorie diet (approximately 1400 kcal/d). Stress tests included maximal and submaximal (85%) exercise, psychological stress, and isometric handgrip tests, all with constant electrocardiogram (ECG) monitoring. Twenty-four-hour Holter monitors at weeks 0 and 6 and weekly resting ECGs were obtained. DO and DE lost similar amounts of weight. There were no changes in QT intervals or in voltage or width of the QRS complex on resting ECG and no arrhythmias on Holter monitoring. These data support the safety of VLCDs containing greater than or equal to 650 kcal/d and adequate amounts of high-quality protein, vitamins, and minerals for use for periods of at least 6 wk in normal, healthy obese women.

Effect of cardiac rehabilitation on postprandial response to a high fat meal in patients with coronary artery disease.

Past studies have shown decreased lipemic responses to a high fat meal in healthy trained vs. untrained subjects. The purpose of this study was to characterize fasting lipid profiles and lipemic responses in 13 male cardiac patients (6 in cardiac rehabilitation (CR) and 7 controls (NONCR]. Body composition and dietary composition were assessed. Plasma total cholesterol (TC), HDL-cholesterol (HDL-C) and triglyceride (TG) were determined after a 12-h fast. Subjects consumed a high fat meal (60% of calories) and the lipemic response to the meal was assessed by determining plasma TG hourly for 8 h following the meal. CR had a lower percent body fat than NONCR (26% vs. 34%, P less than 0.05). CR consumed fewer calories from fat than NONCR (28% vs. 41%, P less than 0.05). There were no significant differences between groups in TC, HDL-C or TG, although the differences approached significance (P less than 0.10). CR had a lower TC/HDL-C ratio than NONCR (5.0 vs. 7.7, P less than 0.05). Lipemic responses between groups were similar. There was no significant difference in peak TG, time to peak TG, or area under the TG curve between CR and NONCR groups. Thus, subjects undergoing cardiac rehabilitation appear to have both a more favorable diet and fasting lipid profile than NONCR; however, both groups had a similar response to a high fat meal.

Effects of high resistance training in coronary artery disease.

Resistive activities for cardiac patients have traditionally been discouraged. The purpose of this study was to assess the safety and efficacy of a 30 min/day, 3 day/week, 10-week strength training program in 9 stable, aerobically trained, male cardiac patients. The strength training program comprised lifting 80% of maximum voluntary contraction at 5 stations: quadriceps extension, bench press, standing biceps curl, hamstring curl and military press and performing 80% of the maximum number of sit-ups in 1 minute. Maximum voluntary contraction for each lift and body composition via body weight, hydrostatic weighing, skinfolds and girths were determined before and after training. The electrocardiogram was monitored during all maximum voluntary contraction lifts and heart rate and systolic and diastolic blood pressures were monitored during all activities. The only change in measures of body composition was an 11% increase in quadriceps girth (p less than 0.05). Maximum voluntary contraction increased 17, 12, 19, 53 and 46% for bench press, military press, standing biceps curl, quadriceps extension and hamstring curl, respectively (p less than 0.01), while the number of sit-ups performed in 1 minute increased 33% (p less than 0.05). No signs or symptoms of ischemia or abnormal heart rate or blood pressure responses were observed during the strength training program. Thus, resistive training at 80% of maximum voluntary contraction appears to be both safe and efficacious in stable, aerobically trained cardiac patients.

Physiologic responses to weight lifting in coronary artery disease.

This study assesses the safety of and physiologic responses to maximal repetition, dynamic, resistive weight lifting at 40, 60, 80 and 100% of maximal voluntary contraction compared with aerobic exercise using a maximal treadmill exercise test. Twelve men with coronary artery disease exercised to fatigue at 4 stations (overhead press, biceps curl, quadriceps extension and supine press). The electrocardiogram was monitored continuously. Heart rate and systolic and diastolic blood pressures (by sphygmomanometer) were measured at rest and during peak exercise. No symptoms or electrocardiographic evidence of ischemia occurred with weight lifting, whereas 5 of 12 patients had ischemic ST-segment depression (> or = 1 mm) with the treadmill. No significant ectopy occurred with either activity. Mean peak heart rates with all lifts were less (range 74 to 92 beats . min-1; p < or = 0.05) than with the treadmill (157 beats . min-1). Peak systolic blood pressures were similar, whereas peak diastolic blood pressures were greater with all lifts (range 93 to 117 mm Hg; p < or = 0.05), except 100% maximal contraction biceps curl and quadriceps extension, than with the treadmill (79 mm Hg). Peak rate pressure product was greater with the treadmill than with all lifts (p < or = 0.05). Diastolic time interval from the electrocardiograph was shorter with the treadmill (0.154 second) than with all lifts (range 0.323 to 0.448 second; p < or = 0.05). Diastolic pressure-time index was greater with all lifts than with the treadmill (p < or = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiographic alterations associated with the hearts of athletes.

Physical conditioning induces numerous cardiovascular adaptations, including vagotonia and increased cardiac volume and mass. These adaptations characterise the 'athletic heart' and account for most of the normal variants in the athlete's electrocardiogram. Common alterations associated with vagotonia include sinus bradycardia, sinus arrhythmia, junctional escape beats, first degree atrioventricular block and second degree (Mobitz type I) atrioventricular block. Common electrocardiographic variants associated with increased cardiac mass and volume include increased voltage, prominent U waves, intraventricular conduction delays, early repolarisation and increased QT intervals. It is sometimes difficult to differentiate the healthy athlete with an athletic heart from the athletic patient with a diseased heart. Thus, further evaluation may be warranted, especially when the athlete also presents with hypertension and/or abnormalities of the cardiovascular physical examination.

Physiological response to circuit weight training in borderline hypertensive subjects.

Male subjects (10 experimental, 16 control) with borderline hypertension (140/90 to 160/95 mm Hg) participated in a circuit weight training program for 9 wk to assess its efficacy and safety. Resting blood pressure and heart rate were measured under standardized conditions prior to and following each session and at several locations in the circuit. Subjects were assessed pre- and post-training. Upper and lower body strength increased 12.5 and 53% when assessed by one-repetition maximum lifts for bench press (57 to 64 kg) and leg press (134 to 205 kg), respectively. Total weight lifted per circuit increased 57% (4,374 to 6,866 kg). Lean body mass increased 2.2% (64.0 to 65.4 kg), skinfold thicknesses decreased, and other measures of body composition remained unchanged. Cardiovascular endurance as assessed by arm ergometry maximal oxygen uptake increased 21.1% (1.9 to 2.3 1 X min-1), and by 7.8% as assessed by treadmill maximal oxygen uptake (40.9 to 44.1 ml X kg-1 X min-1). Resting heart rate and systolic blood pressure did not change. Diastolic blood pressure fell from 95.8 to 91.3 mm Hg. All changes were significant to at least P less than 0.05. Thus, circuit weight training can elicit marked improvements in muscular strength and modest improvements in body composition and cardiorespiratory endurance. Circuit weight training does not exacerbate resting or exercise blood pressure and may have beneficial effects.

Estimates of Type A behavior do not predict perceived exertion during graded exercise.

Earlier studies have concluded that exercise tolerance during graded stress testing is overestimated in males showing the Type A Behavior Pattern (TABP) because of high motivation and suppressed ratings of perceived exertion (RPE). However, the studies used the Jenkins Activity Survey (JAS) to assess TABP and employed exercise protocols that were unstandardized or uninterpretable for clinical prescription. Because the JAS lacks validity for predicting the criterion Structured Interview (SI) for TABP, the usefulness of concurrent self-report estimates of TABP for predicting RPE during standard exercise testing warrants additional study. During clinical treadmill testing of 86 asymptomatic Caucasian men (45 +/- 9 yr), we examined three standard estimates of TABP (JAS, Bortner, Framingham) as predictors of: 1) the covariance (RPE') of RPE (Borg Category Scale) with VO2 (ml.kg-1.min-1) during 5 min of graded walking (5.47 km.h-1, 2.25%.min-1); 2) VO2 and RPE (11.6 +/- 2.2) at a preferred level of exertion (approximately 65% +/- 10% VO2PEAK); 3) VO2PEAK and RPE at VO2PEAK. Multiple linear regression analyses found no relations (P greater than 0.10) between estimates of TABP and treadmill responses. Discriminant analyses of Type A and Type B groups formed from tertiles consistent with population norms showed no differences (P greater than 0.01) for RPE of treadmill performance. Our findings question prior reports of RPE suppression associated with TABP estimates. We conclude that practically implementable estimates of TABP do not offer useful information for clinical predictions of RPE, preferred exertion level, or VO2PEAK in asymptomatic middle-aged Caucasian men.

Triathlete characterization and response to prolonged strenuous competition.

The purpose of this study was to characterize triathletes and to assess their responses to prolonged, strenuous competition. Nine triathletes (6 males, 3 females) participated. Mean V0(2)max and percentage of body fat were 72.0 ml X kg-1 X min-1 and 7.1%, respectively, in the four males who finished in the top 15. This compared to values of 58.4 ml X kg-1 X min-1/10.2% and 58.7 ml X kg-1 X min-1/12.6% in the other males and females, respectively. In the 5 wk preceding competition (Hawaii "Ironman Triathlon World Championship") the average daily training of the four top 15 male competitors consisted of swimming 2720 m, running 13.6 km, and biking 84.0 km. This was approximately 1.5 times greater than that of the other athletes. The average training diet was 59% carbohydrate, 21% fat, and 20% protein. Immediately following competition, SGOT, SGPT, and serum LDH were increased 700, 262, and 222% (P less than 0.004), respectively, and still remained marginally elevated 5-6 d later (P less than 0.02). Immediately following competition, serum triglycerides remained unchanged, while serum glucose, glycerol, and nonesterified fatty acids increased 52, 248, and 191% (P less than 0.005), respectively. By 5-6 d post-competition glucose had returned to normal, while triglycerides were elevated 94% (P less than 0.005) and nonsterified fatty acids were decreased 58% (P less than 0.01).

Postprandial effect of a high fat meal on plasma lipid, lipoprotein cholesterol and apolipoprotein measurements.

We investigated the effect of a fatty meal on plasma concentrations of lipids, apolipoproteins, and the cholesterol component of lipoproteins. Sixteen nonobese, healthy, asymptomatic males, 22-34 years of age, served as subjects for this study. None smoked, consumed more than two alcoholic drinks per day, or took any medication known to alter plasma lipids. After a 12 h fast, baseline plasma samples were obtained just before subjects consumed a high fat meal. The meal, standardized to a 70 kg individual, contained approximately 70 g fat, 580 mg cholesterol, and 1,100 cal, with 56% of the calories coming from fat. During the 8 h following consumption of the meal, subjects rested quietly and consumed no food or beverages except water. Blood specimens were obtained hourly. There was a significant increase in plasma triglyceride (150% from baseline at 3 h, P less than 0.0005). Very low density lipoprotein cholesterol (VLDL-C) concentrations increased 150% at 3 h (P less than 0.0005) while low density lipoprotein cholesterol (LDL-C) concentration decreased 37% at 3 h (P less than 0.005) when estimated by Friedewald's formula. No statistically significant differences were observed between fasting total cholesterol, high density lipoprotein cholesterol (HDL-C). HDL2-C, and HDL3-C, apolipoprotein AI (apo AI, AII), and B-100 concentrations and non-fasting samples. We conclude that plasma triglyceride concentration is significantly affected in the post-prandial state. As a result, VLDL-C and LDL-C when assessed by the Friedewald formula are also altered. A minimum of 8 h fasting is required to assess these concentrations accurately in this population.(ABSTRACT TRUNCATED AT 250 WORDS)

High-Frequency, Moderate-Intensity Training in Sedentary Middle-aged Women.

In brief: The effects of a five-day-a-week, moderate-intensity aerobic training program were studied in previously sedentary middle-aged women. The subjects trained for ten weeks, and the periods of continuous exercise within each training session were lengthened gradually to allow them to adapt physiologically. Afterward the subjects showed a 20% improvement in V o2 max but no change in body weight or compsition. None of the women suffered an orthopedic injury. The study suggests that this type of program is a safe and effective exercise prescription for sedentary middle-aged women.

Stretch-induced growth in chicken wing muscles: biochemical and morphological characterization.

Skeletal muscle growth induced by passive stretch was characterized in chicken wing muscles. Within 24 h after installing the stretch apparatus on the birds, the sarcomere length of the stretched patagialis was 40% greater than control. This was accompanied by increasing muscle wet weight, protein content, DNA and RNA concentrations. Sarcomere length returned to near control values by 3 days, but muscle wet weight and protein content continued to increase through 10 days. DNA and RNA concentrations reached a peak after 5-7 days and began to decline. Histological examination after 7 days revealed no change in the concentration of nuclei inside the basement membrane surrounding the muscle fibers, but the concentration of nuclei outside the basement membrane had increased. Therefore, the ratio of protein to DNA can be a poor index of muscle fiber DNA unit size. Additionally, no evidence of new muscle fiber formation was found. Electron microscopy demonstrated that passive stretch destroyed sarcomere registration between adjacent myofibrils. We concluded that passive stretch is a powerful inducer of muscle growth.

Effects of graded duration of stretch on normal and dystrophic skeletal muscle.

Daily passive stretch for six weeks ranging from 30 minutes to 24 hours per day was studied in the patagialis (PAT) muscle of normal and dystrophic chickens. Significant increases in wet weight, cross-sectional area, and mean fiber cross-sectional area occurred in both normal and dystrophic PAT in response to stretch of all daily durations tested. More than 50% of the growth occurring in response to continuous stretch was elicited by as little as 30 minutes of stretch per day. Oxidative enzyme capacity increased proportionately with increasing durations of stretch in the normal PAT. Similarly, increasing duration of stretch progressively retarded the onset of histopathological signs in the dystrophic PAT. We conclude that daily stretching for as little as 30 minutes per day is a powerful inducer of growth in normal and dystrophic muscle and that the progress of the histopathology in dystrophic muscle is delayed in proportion to the daily duration of stretch.

The value of chest pain during the exercise tolerance test in predicting coronary artery disease.

UNLABELLED: The predictive power of 10 common exercise test parameters compared with coronary angiography was studied. Only the exercise electrocardiogram (EXECG), maximal rate pressure product (MAXRPP), and exercise chest pain (EXCP) contributed unique predictive information with the emergence of two interactions involving EXCP (EXCP.EXECG and EXCP.MAXRPP). IN CONCLUSION: (1) EXCP appears to be a more serious finding only in those higher risk individuals with either a positive EXECG or lower MAXRPP; (2) EXCP and its interactions may help discriminate between anginal and nonanginal, exertional chest pain, and (3) the contradictory results found when EXCP was allowed to interact may explain conflicting results in previous multivariate models regarding the predictive significance of EXCP.

Effects of Hatha Yoga Practice on the Health-Related Aspects of Physical Fitness.

Ten healthy, untrained volunteers (nine females and one male), ranging in age from 18-27 years, were studied to determine the effects of hatha yoga practice on the health-related aspects of physical fitness, including muscular strength and endurance, flexibility, cardiorespiratory fitness, body composition, and pulmonary function. Subjects were required to attend a minimum of two yoga classes per week for a total of 8 weeks. Each yoga session consisted of 10 minutes of pranayamas (breath-control exercises), 15 minutes of dynamic warm-up exercises, 50 minutes of asanas (yoga postures), and 10 minutes of supine relaxation in savasana (corpse pose). The subjects were evaluated before and after the 8-week training program. Isokinetic muscular strength for elbow extension, elbow flexion, and knee extension increased by 31%, 19%, and 28% (p<0.05), respectively, whereas isometric muscular endurance for knee flexion increased 57% (p<0.01). Ankle flexibility, shoulder elevation, trunk extension, and trunk flexion increased by 13% (p<0.01), 155% (p<0.001), 188% (p<0.001), and 14% (p<0.05), respectively. Absolute and relative maximal oxygen uptake increased by 7% and 6%, respectively (p<0.01). These findings indicate that regular hatha yoga practice can elicit improvements in the health-related aspects of physical fitness. (c)2001 CHF, Inc.

The value of ten common exercise tolerance test measures in predicting coronary disease in symptomatic females.

The diagnostic contribution of ten common exercise tolerance test (ETT) measures compared with coronary angiography was studied in 62 symptomatic females (mean age = 53 +/- 9 years). Logistic regression revealed that maximal ST-segment depression, the percent of predicted maximal heart rate achieved, and test chest pain all contributed unique predictive information and formed a model generating probabilities for coronary disease (CAD). Using a predicted probability for the presence of CAD of 0.50 as a cutpoint, test accuracy was markedly improved (sensitivity = 73%, specificity = 94%, and overall correct classification rate = 90%) over the standard ST response. We conclude that multivariate analysis using these three easily assessed ETT measures provides superior discrimination between symptomatic women with and without CAD when compared to changes in the ST-segment alone.

Hyperlipemic response of young trained and untrained men after a high fat meal.

To test the hypothesis that endurance training is associated with a decreased lipemia after a high fat meal, 16 young men [22 to 34 years old, nine of whom were trained (T) and seven of whom were untrained (UT)] were recruited. T ran greater than 30 or biked greater than 100 miles a week, while UT had been sedentary for at least the preceding 3 months. Daily caloric intake and daily caloric expenditure during exercise were 35% and 704% greater, respectively, in T than in UT. VO2max was 31% greater, while percent body fat was 36% lower in T than in UT. Dietary composition and body height and weight were similar. After a fasting blood sample was taken, the men ate a high fat meal (approximately 56% of total calories as fat in 1100 kcal adjusted to body weight), and additional blood samples were taken hourly for 8 hours. Fasting lipids were similar. Postprandial peak triglyceride (TGmax), percent TG increase (%TGI), and total lipemic response (TLR, the area under the lipemia curve in excess of fasting TG) were 42%, 54%, and 75% greater, respectively, in UT vs. T. Stepwise regression analysis showed that the same three-variable model (training status, fasting TG, and VO2max) described the variation in TGmax (R2 = 0.97), %TGI (R2 = 0.75), and TLR (R2 = 0.92). Furthermore, this same analysis showed that after adjustment for fasting TG and VO2max, the UT group had a significantly greater postprandial lipemia whether expressed as TGmax (p less than 0.0001), %TGI (p = 0.0002), or TLR (p = 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

Stretch-induced growth in chicken wing muscles: a new model of stretch hypertrophy.

A new model of stretch-induced growth is evaluated in four chicken wing muscles stretched to different extents by a spring-loaded tubular assembly. Muscles grew in length and cross section in proportion to the extent to which they were stretched. Longitudinal growth was essentially completed within 1 wk, while muscles grew in cross section through at least 5 wk of stretch. The muscles were neither denervated nor immobilized, and muscle activity as measured by EMG was not increased. Oxidative enzyme activities increased substantially with stretch in the patagialis (PAT), a twitch muscle, but were relatively unchanged in the slow-tonic anterior latissimus dorsi (ALD). Stretch altered mitochondrial enzyme proportions in the PAT, but had little effect in the ALD. Capillary density was unchanged with stretch in the PAT, but decreased in the ALD. Capillary density was unchanged with stretch in the PAT, but decreased in the ALD. Capillary-to-fiber ratio, however, increased in both muscles. We conclude that muscles grow and adapt enzymatically due to stretch, but that these responses are dissimilar in twitch and tonic muscles.