No description available.

Hypothesis. We hypothesized that contrary to "normal aging," frail elderly women would have a heightened resting energy expenditure per kg fat free mass (REE/kg FFM) and thermic effect of food (TEF) response. / Methods. 13 healthy (H) [X +/- SEM: 81.4 +/- 1.1 yr] and 9 frail elderly women (F) [84.7 +/- 1.6 yr], free from acute conditions underwent REE and TEF measurements (liquid standard mixed meal: 720 kcal, 58% carbohydrate, 14% protein, 28% fat) using ventilated hood indirect calorimetry. Anthropometric and body composition measurements, thyroid hormones, cortisol, cytokines and catecholamine concentrations, and physical activity (PASE) and mobility ("time up and go" TUG) scores were related to the results obtained. / Results. H had a faster TUG: 10.2 +/- 1.6 vs. 21.0 +/- 9.3 s (p=0.001), greater PASE score: 179.2 +/- 116.1 vs. 47.1 +/- 26.2 (p=0.003), greater triiodothyronine [T3]: 5.1 +/- 0.6 vs. 4.3 +/- 0.4 rhomol/L (p=0.003) and lower cortisol concentrations: 351.1 +/- 19.9 vs. 474.5 +/- 43.6 nmol/L (p=0.011). In H vs. F: REE/kg FFM was 1044 +/- 20.4, 1021 +/- 23.7 kcal/day (NS) and TEF response as expressed as % of REE was 18.4 +/- 5.6, 19.5 +/- 4.2 (NS). The time course of glucose (p=0.043) and insulin from 90 minutes onwards (P=0.013) suggested insulin resistance in F. REE was positively correlated with FFM, percent body fat and [T3] (r>0.499, p<0.021). / Conclusion. REE/kg FFM and TEF response was not different between H and F and thus the greater prevalence of malnutrition in F, cannot be explained by these parameters.

This study examined and compared the effects of ingesting four different, isocaloric carbohydrate meals (460 kcals), two hour prior to a 60 minute bout of endurance cycling. The meals were chosen to represent a variety of types, forms and modes of delivery of carbohydrate: i) Banana Nut Bread®: semi-liquid, oat based carbohydrate-fat-protein combination, ii) Oatmeal: semi-liquid, oat based carbohydrate, iii) Cream of Wheat®: semiliquid, wheat based carbohydrate, iv) Power BarsTM: dense solid, fructose based carbohydrate-protein-vitamin combination. A standardized exercise and dietary regimen was followed prior to each performance trial. The purpose of the pre-trial preparation was to standardize each subjects endogenous carbohydrate stores thereby placing greater emphasis on the ability of each experimental meal to maintain blood glucose. Dependent variables were assessed at 15 minutes intervals during each performance trial to determine if any of the meals could elicit a different physiological response. No significant differences (treatment x trial) in blood glucose concentration, distance traveled, heart rate, V02, RER or RPE were observed (p > 0.05). It was concluded that none of the experimental meals conferred any particular advantage over the rest and due to this fact, issues such as personal preference, convenience and cost should be considered. / School of Physical Education

The purpose of this study was to determine if previously observed differences in ratings of perceived exertion (RPE) at the same intensities during two graded exercise tests (GXT) were the result of changes in blood lactate concentrations (BLC). Thirteen healthy males (25.3 ±53 yrs.) were maximally tested during two protocols (Bruce and Balke 3.0 mph/2.5 % grade changes every 2 minutes). Subjects were randomly assigned to one GXT and completed the second test after 48 hours; both were completed within one week. Ratings of perceived exertion (RPE) were recorded at the end of each 2 minute stage of the Balke and twice per stage during the Bruce protocol. Blood lactate concentrations (BLC) were collected each minute during both protocols.Results: RPE data was first analyzed using two-way ANOVA (protocol x intensity), and a significant interaction was observed with RPEs being higher at each intensity during the Balke protocol. Mean RPE differences were 1.4, 2.8, and 4.5 for 40, 60, 80% of VO2max respectively. The addition of the BLC at each relative exercise intensity as a covariate in the model suggested that BLC accounted for some of the protocol differences in RPE, at 60 and 80% of VOimax.Conclusion: Differences in RPEs between standard GXT protocols reported in previous studies were due, in part, to differences in BLC. / School of Physical Education

Considerable research has been performed on the effects of exercise and glucose tolerance, however, most of this work has examined aerobic exercise designs. This study examines the immediate post-exercise glucose turnover in eight male subjects exposed to a single bout of running and PRE. Both exercise protocols were designed to be of similar duration and at an intensity representing a typical exercise session. This study was conducted in an effort to offer individuals with NIDDM an alternative to the established aerobic forms of exercise for improved glucose control. Each subject completed two preliminary procedures, which consisted of a maximal graded exercise test and a session where a 1 RM was established on six different Cybex variable resistance machines. Subjects then completed a baseline oral glucose tolerance test (OGTT) in which eight blood samples were analyzed for glucose, insulin, hemoglobin, and hematocrit. Two exercise protocols, separated by 3 to 10 days, consisting of a 40 minute treadmill run at 75% VO2max and a 40 minute, 3 set x 10 repetition based on 75% of the1 RM, were performed and followed 45 minutes later by another OGTT. The results demonstrated that there were no apparent differences in blood glucose or insulin levels post-exercise between the exercise modes. However, the form of exercise did seem to have a varied effect on insulin production. The results of the OGTT demonstrated an explicit difference in the insulin response between the lifting and running trials, with the lifting trial being significantly higher than the resting or running trials. The increased insulin levels observed in the lifting trial may be indicative of increased secretion from the pancreas or that the secreted insulin is simply not being used. The insulin resistance observed in the lifting trial may be due to the muscles inability to respond to insulin or some other metabolic factor(s) released during exercise. Additional studies should be performed on different populations to examine the effects of PRE and running in a effort to better understand the mechanisms responsible for glucose uptake. / School of Physical Education

Maintenance of adequate muscle glycogen stores has been shown to be essential for endurance performance. For athletes who train on successive days or twice in the same day it is especially important that feeding strategies result in optimal glycogen resynthesis between workouts. The purpose of this investigation was to determine if prior carbohydrate feedings and the form of the carbohydrate consumed affected subsequent endurance performance. Seven endurance trained male cyclists agreed to participate in this study. Each day of testing consisted of two exercise bouts. The first workout was an anaerobic workout consisting of five one minute efforts at 115% VO2max followed by a sprint ride to exhaustion. Each of the sprints was separated from the next by a four minute rest period. For the final ride, the subjects rode at 115% of VO2max. One hour following the completion of the first workout, the subjects began a feeding regimen in which one of four carbohydrate sources were ingested in an amount calculated to provide 1.5g carbohydrate/kg bodyweight/hr for the next four hours. The trials were grouped by carbohydrate forms, dense chewy solid (Powerbars) (DCS), liquid carbohydrate (Gatorlode) (LCHO), and semi-moist solid (Nabisco Snackwells and Fruit Newtons) (SMS). In addition, a water trial (W) was conducted to serve as a control The second workout occurred six hours after the completion of the anaerobic workout and consisted of a one-hour self-paced performance ride on a cycle ergometer. Performance was measured as work (U) performed during the ride. All carbohydrate forms (824.7±109.6 U) improved performance over water (782.0±121.7 U) (p<0.05). In addition, among the various carbohydrate forms, SMS (843.2±94.4 U) significantly improved performance over LCHO (807.3±141 U) and DCS (805.3±115 U) (p<0.05). Carbohydrate feedings between anaerobic and aerobic workouts in the same day improve performance. Also, the physical form of the carbohydrate influences performance. / School of Physical Education

The present study was designed to evaluate the influence of carbohydrate structure on muscle glycogen resynthesis. Eight college-aged male cyclists performed a depletion exercise protocol to decrease vastus lateralis glycogen concentration. This protocol consisted of 60 min of cycling at 75% V O2max, followed by 6 - one min sprints at 125 % V O2max, with a 1 min rest between each sprint. Following the depletion exercise, the subjects consumed - 3000 kcal over a 12 hour period, which was calculated to meet each subject's estimated daily energy expenditure. The carbohydrate (CHO), fat and protein content represented 65:20:15% of the calories consumed, respectively, and totaled 450 - 550 g of CHO. All of the CHO was derived from 1 of 4 solutions: 1) glucose, 2) maltodextrin (glucose polymer), 3) waxy starch (100% amylopectin), or 4) resistant starch (100% amylose). Muscle biopsies were taken after the depletion exercise protocol and 24 hours after the depletion protocol to determine glycogen concentrations. The postdepletion exercise glycogen concentration was similar in all 4 trials, and averaged 234.7 mmol/kg dry weight (d.w.) muscle. Twenty-four hours after exercise, the increase in muscle glycogen concentration was less in the resistant starch trial (90.8 f 12.8 mmol/kg d.w.) than in the glucose, maltodextrin and waxy starch trials, in which glycogen concentration increased 168.7 mmol/kg d.w. Following the 24 h post-depletion exercise biopsy, each subject performed a 30 min cycling time trial, so that the relationship between muscle glycogen concentration and performance could be examined. There were no differences in work output during the time trial or blood lactate concentration immediately following the time trial in any of the trials. In summary, glycogen resynthesis is attenuated following ingestion of carbohydrate with a high amylose content, relative to amylopectin or glucose; however, short duration performance at intensities < 75% VO2max is unaffected. / School of Physical Education

The purpose of this study was to examine if measurements of submaximal blood lactate may improve the prediction of VO2max from submaximal exercise tests. Subjects (39 men & 21 women, age 20-44 yrs) completed a branching protocol on a cycle ergometer which consisted of 3 submaximal stages of 4 minutes each followed by a maximal effort. During the last minute of each stage heart rate (HR) was recorded from telemetry and a capillary blood sample was obtained from a finger puncture. Maximal power output was estimated from the extrapolation of the 3 submaximal HRs to age predicted HRmax and blood lactate concentration was measured using a Yellow Springs analyzer (Yellow Springs, OH). Data were analyzed using multiple regression procedures. Estimated maximal power output (238 ± 56 W) was significantly related to measured VOzmaX (p < 0.001, r2= .523). Mean values for ACSM estimated, ACSM-revised and measured VOz.X were not significantly different (3.170 vs. 3.140 vs. 3.260 L/min respectively), however the SEE % for the ACSM and ACSM revised estimated VOz,. were 13.4% and 12.1%, respectively. When the change in power output relative to the change in blood lactate concentrations (po/BL) from stage 1 to stage 2 and the estimated maximal power output from 3 submaximal heart rates were added as independent variables to the regression model with measured VO2,t as the dependent variable, po/BL was significantly correlated with VO X , accounting for 7.6% of the variance in VOz... In conclusion, only the relative change in power output to the relative change in blood lactate measure from stage 1 to _2 were significant in improving the estimation of VO2 during submaximal exercise tests using a branching protocol. Other blood lactate measures did not improve the estimation of VOA,. in this study. / School of Physical Education

Insulin-like growth factor-I (IGF-I) is a known stimulator of glucose transport. IGF binding protein 1 (IGFBP1) is a protein that regulates the actions of IGF-I by binding to IGF-I which alters it's ability to bind to the IGF-I receptor. Diet and exercise may influence this system. While IGFBP1 levels increase with fasting or prolonged exercise, feeding will reverse this elevation. The intent of this study was to determine if an in vivo manipulation of IGFBP1 affects in vitro glucose transport in the rat soleus. Sixteen male Spaque Dawley rats were fasted for 12 hours. Half of the animals were then allowed a two hour ad libitum refeeding period. Animals were anesthetized and had their soleus muscles removed. Muscles were then randomly assigned to one of four treatment groups. Treatments involved an incubation in either 4 or 8 mM glucose in either the presence or absence of IGF-I (75 ng x ml"'). Final incubation for all treatment groups included [3H]-3-O-methylglucose (437 µCi x mM-) for the measurement of glucose transport. Following incubation, muscles were weighed, homogenized in 1 ml of 10% trichloroacetic acid, and centrifuged to precipitate out protein. 100 µl of the supernatant was added to 3 ml of scintillation fluid and analyzed in a scintillation counter. Glucose transport was determined by 3H activity. A statistical analysis of the various groups shows that there is no significant difference between fasted and refed animal for any specific treatment. However, when all the fasted and refed animals area grouped, glucose transport rate is significantly greater (p<0.05) in fasted (3.59 ± 0.44 µM x ml"' x hr) animals than in refed animals (2.56 ± 0.27 µM x ml"' x hr'). Additionally, muscles that were treated with IGF-I in 8 mM glucose demonstrated a greater rate of glucose transport (5.12 ± 0.68 µM x ml-1 x hr') than all other treatments (2.13 ± 0.39 to 2.90 ± .33 µM x ml-' x hr'). This study showed that IGF-I is a stimulator of glucose transport in an 8 mM glucose media. Additionally, the results show that glucose transport is greater if the animals are fasted. The differences between fasted and refed animals demonstrated in this study supports the hypothesis that diet manipulated IGFBP1 levels are able to alter the biological effects of IGF-I. / School of Physical Education

The purpose of this study was to examine the effects of warm-up intensity on anaerobic performance and recovery in children. Six male children (11.0 ± 0.6 yr) performed an IAT following a mild (85% of VAT), intense (115% of VAT), or no warm-up protocol. VAT was determined during a previously performed GXT. A catheter allowed for multiple blood samples drawn thoughout each trial. Performance indices, PP, MP, TW, and FI%, were not significantly different across trials. Blood analysis revealed significant interactions for recovery [LA] and [HC03-], although no significant interaction for pH values. There was also a significant interaction for V02 recovery pattern. The ALA (5.2 vs. 7.1 mmol•1-1, respectively) and AHC03- (6.1 vs. 8.4 mmol-l-1, respectively) were significantly lower for the AVAT trial compared to NWU trial. These data indicate that the AVAT warm-up resulted in less acid-base balance disturbance suggesting greater dependence on aerobic metabolism during the IAT. / School of Physical Education