The Effect of Choline and Resistance Training on Strength and Lean Mass in Older Adults.

Choline plays many important roles, including the synthesis of acetylcholine, and may affect muscle responses to exercise. We previously observed correlations between low choline intake and reduced gains in strength and lean mass following a 12-week resistance exercise training (RET) program for older adults. To further explore these findings, we conducted a randomized controlled trial. Three groups of 50-to-69-year-old healthy adults underwent a 12-week RET program (3x/week, 3 sets, 8-12 reps, 70% of maximum strength (1RM)) and submitted >48 diet logs (>4x/week for 12 weeks). Participants' diets were supplemented with 0.7 mg/kg lean/d (low, n = 13), 2.8 mg/kg lean/d (med, n = 11), or 7.5 mg/kg lean/d (high, n = 13) of choline from egg yolk and protein powder. The ANCOVA tests showed that low choline intake, compared with med or high choline intakes, resulted in significantly diminished gains in composite strength (leg press + chest press 1RM; low, 19.4 ± 8.2%; med, 46.8 ± 8.9%; high, 47.4 ± 8.1%; p = 0.034) and thigh-muscle quality (leg press 1RM/thigh lean mass; low, 12.3 ± 9.6%; med/high, 46.4 ± 7.0%; p = 0.010) after controlling for lean mass, protein, betaine, and vitamin B12. These data suggest that low choline intake may negatively affect strength gains with RET in older adults.

Assessment of Vascular Function in Response to High-Fat and Low-Fat Ground Beef Consumption in Men.

Red meat is stigmatized as an unhealthy protein choice; however, its impacts on vascular function have not been evaluated. We aimed to measure the vascular impact of adding either low-fat (~5% fat) ground beef (LFB) or high-fat (~25% fat) ground beef (HFB) to a habitual diet in free-living men. Twenty-three males (39.9 ± 10.8 years, 177.5 ± 6.7 cm, 97.3 ± 25.0 kg) participated in this double-blind crossover study. Assessment of vascular function and aerobic capacity were measured at entry and in the last week of each intervention and washout period. Participants then completed two 5-week dietary interventions (LFB or HFB; 5 patties/week) in a randomized order with a 4-week washout. Data were analyzed via 2 × 2 repeated-measures ANOVA (p < 0.05). The HFB intervention improved FMD relative to all other time points, while lowering systolic (SBP) and diastolic blood pressure (DBP) relative to entry. Neither the HFB nor the LFB altered pulse wave velocity. The addition of either low- or high-fat ground beef did not negatively alter vascular function. In fact, consuming HFB improved FMD and BP values, which may be mediated by lowering LDL-C concentrations.

Consuming High-Fat and Low-Fat Ground Beef Depresses High-Density and Low-Density Lipoprotein Cholesterol Concentrations, and Reduces Small, Dense Low-Density Lipoprotein Particle Abundance.

We hypothesized that consumption of high-fat (HF) ground beef (24% fat) would not affect plasma concentrations of high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein (LDL-C), whereas low-fat (LF) ground beef (5% fat) would decrease HDL-C and LDL-C concentrations. In a randomized 2-period crossover, controlled feeding trial, 25 men (mean age and body mass index, 40 years and 31.2) consumed 115-g HF or LF patties, 5/week for 5 weeks with a 4-week washout. The HF treatment increased % energy from fat (p = 0.006) and saturated fat (p = 0.004) and tended (p = 0.060) to depress % energy from carbohydrates. The HF and LF treatments decreased the plasma concentrations of HDL-C (p = 0.001) and LDL-C (p = 0.011). Both ground beef treatments decreased the abundance of HDL3a and increased the abundance of HDL3 (p ≤ 0.003); the LF treatment also decreased the abundance of HDL2b and HDL2a (p ≤ 0.012). The HF and LF treatments decreased the abundance of LDL3 and LDL4 (p ≤ 0.024) and the HF treatment also decreased LDL5 (p = 0.041). Contrary to our hypothesis, the HF treatment decreased plasma HDL-C and LDL-C concentrations despite increased saturated fat intake, and both treatments decreased the abundance of smaller, denser LDL subfractions.

Predicting muscular strength using demographics, skeletal dimensions, and body composition measures.

The purpose of this study was to develop an equation to predict strength for seven common resistance training exercises using anthropometric and demographic measures. One-hundred forty-seven healthy adults (74 males, 73 females, 35 ±â€¯12 yr, 174 ±â€¯10 cm, 88 ±â€¯19 kg) volunteered to participate. Body composition values (regional/total) and body dimensions were assessed using dual-energy x-ray absorptiometry (DEXA). Subjects underwent the following maximal strength assessments: Leg Press, Chest Press, Leg Curl, Lat Pulldown, Leg Extension, Triceps Pushdown, and Biceps Curl. Multiple linear regression with stepwise removal was used to determine the best model to predict maximal strength for each exercise. Independent predictor variables identified (p < 0.05) were height (cm); weight (kg); BMI; age; sex (0 = F,1 = M); regional lean masses (LM,kg); fat mass (FM,kg); fat free mass (FFM,kg); percent fat (%BF); arm, leg, and trunk lengths (AL, LL, TL; cm); and shoulder width (SW,cm). Analyses were performed with and without regional measures to accommodate scenarios where DEXA is unavailable. All models presented were significant (p < 0.05, R 2 = 0.68-0.83), with regional models producing the greatest accuracy. Results indicate that maximal strength for individual resistance exercises can be reasonably estimated in adults.

Effects of an Acute Strength and Conditioning Training Session on Dual-Energy X-Ray Absorptiometry Results.

Lytle, JR, Stanelle, ST, Kravits, DM, Ellsworth, RL, Martin, SE, Green, JS, and Crouse, SF. Effects of an acute strength and conditioning training session on dual-energy x-ray absorptiometry results. J Strength Cond Res 34(4): 901-904, 2020-The purpose of this study was to determine whether an athletic strength and conditioning (S&C) session will alter body composition estimates of a dual-energy x-ray absorptiometry (DXA) scan. Twenty-two strength-trained individuals (15 men, 7 women, 24 ± 2 years, 174.2 ± 8.5 cm, 83.5 ± 15.0 kg) volunteered to participate in the study. Each subject underwent 2 DXA scans, before and after completion of the S&C session, which consisted of upper- and lower-body resistance exercises and interval running. Subjects consumed a free-living meal before the first scan, after which only ad libitum water intake was consumed until completing the second scan. Results were analyzed through sex by time repeated-measures analysis of variance. If no interaction effect was observed, results were next analyzed through correlated t-test (α = 0.05). Significant sex by time interactions were observed for arm total and lean mass, as well as a significant main effect of time showing a decrease in arm lean mass after the S&C session. Values before and after the S&C session that resulted in significant differences via correlated t-test are displayed in Table 1. Results revealed a significant decrease in total mass, arm and leg percent fat, and trunk lean mass, and an increase in leg lean mass.

Wearable positive end-expiratory pressure valve improves exercise performance.

We tested a PEEP (4.2 cmH2O) mouthpiece (PMP) on maximal cycling performance in healthy adults. Experiment-1, PMP vs. non-PMP mouthpiece (CON) [n  = 9 (5♂), Age = 30 ±â€¯2 yr]; Experiment-2, PMP vs. no mouthpiece (NMP) [n = 10 (7♂), Age = 27 ±â€¯1 yr]. At timepoint 1 in both experiments (mouthpiece condition randomized) subjects performed graded cycling testing (GXT) (Corival® cycle ergometer) to determine V ˙ O2peak (ml∗kg∗min -1), O2pulse (mlO2∗bt -1), GXT endurance time (GXT-T(s)), and V ˙ O2(ml∗kg∗min -1)-at-ventilatory-threshold ( V ˙ O2 @VT). At timepoint 2 72 h later, subjects completed a ventilatory-threshold-endurance-ride [VTER(s)] timed to exhaustion at V ˙ O2 @VT power (W). One week later at timepoints 3 and 4 (time-of-day controlled), subjects repeated testing protocols under the alternate mouthpiece condition. Selected results (paired T-test, p<0.05): Experiment 1 PMP vs. CON, respectively: V ˙ O2peak â€‹= â€‹45.2 â€‹± â€‹2.4 vs. 42.4 â€‹± â€‹2.3 p<0.05; V ˙ O2@VT â€‹= â€‹33.7 â€‹± â€‹2.0 vs. 32.3 â€‹± â€‹1.6; GXT-TTE â€‹= â€‹521.7 â€‹± â€‹73.4 vs. 495.3 â€‹± â€‹72.8 (p<0.05); VTER â€‹= â€‹846.2 â€‹± â€‹166.0 vs. 743.1 â€‹± â€‹124.7; O2pulse â€‹= â€‹24.5 â€‹± â€‹1.4 vs. 23.1 â€‹± â€‹1.3 (p<0.05). Experiment 2 PMP vs. NMP, respectively: V ˙ O2peak â€‹= â€‹43.3 â€‹± â€‹1.6 vs. 41.7 â€‹± â€‹1.6 (p<0.05); V ˙ O2@VT â€‹= â€‹31.1 â€‹± â€‹1.2 vs. 29.1 â€‹± â€‹1.3 (p<0.05); GXT-TTE â€‹= â€‹511.7 â€‹± â€‹49.6 vs. 486.4 â€‹± â€‹49.6 (p<0.05); VTER 872.4 â€‹± â€‹134.0 vs. 792.9 â€‹± â€‹122.4; O2pulse â€‹= â€‹24.1 â€‹± â€‹0.9 vs. 23.4 â€‹± â€‹0.9 (p<0.05). Results demonstrate that the PMP conferred a significant performance benefit to cyclists completing high intensity cycling exercise.

One Week of L-Citrulline Supplementation Improves Performance in Trained Cyclists.

Stanelle, ST, McLaughlin, KL, and Crouse, SF. One week of L-citrulline supplementation improves performance in trained cyclists. J Strength Cond Res 34(3): 647-652, 2020-L-citrulline (CIT) is a nonessential amino acid that is touted as an ergogenic aid for athletic performance because of its purported ability to stimulate nitric oxide production. Although previous research has demonstrated that CIT supplementation over a period of days improves physiological factors such as V[Combining Dot Above]O2 kinetics, no studies to date have explored whether there is a direct benefit to endurance performance. This study used a randomized, double-blind, crossover design to test whether chronic supplementation with pure CIT improves cycling performance over a maltodextrin placebo (PLAC). Nine trained male cyclists (24 ± 3 years; 181 ± 7 cm; 76 ± 13 kg; 4.18 ± 0.51 L·min V[Combining Dot Above]O2max) completed two 7-day supplementation periods (6 g·d of CIT or PLAC) separated by a 7-day washout. Subjects consumed the final 6-g dose 2 hours before the cycling performance evaluation, which consisted of a 40-km time trial (TT) followed by a supramaximal sprint repeat task (SRT). Paired t-tests and repeated-measures analysis of variance (α = 0.05) were used to analyze TT and SRT data, respectively. CIT supplementation produced an improvement in TT time of 5.2% that trended toward significance (p = 0.08). Furthermore, CIT promoted a significant increase in average heart rate, average rating of perceived exertion, and average power throughout the TT (p < 0.05). However, supplementation with CIT did not prevent fatigue during the SRT. Overall, this study is the first to demonstrate that CIT supplementation may provide a modest improvement to endurance cycling performance in trained athletes.

Predicting V[Combining Dot Above]O2max From Treadmill Performance in American-Style Football Athletes.

Crouse, SF, Tolson, H, Lytle, J, Johnson, KA, Martin, SE, Green, JS, Oliver, J, Carbuhn, A, Lambert, B, and Bramhall, JP. Predicting V[Combining Dot Above]O2max from treadmill performance in American-style football athletes. J Strength Cond Res 33(4): 1028-1034, 2019-Prediction equations are often used to estimate V[Combining Dot Above]O2max in the general population but are lacking for American-style football (ASF) athletes. We sought to develop a regression model to estimate V[Combining Dot Above]O2max from treadmill exercise time in ASF athletes and compare our football V[Combining Dot Above]O2max model with 2 published prediction equations (Foster et al., 1984, and Bruce, 1973). American-style football athletes (N = 472, age = 18 ± 1 year, height = 186.1 ± 8.2 cm, and body mass = 101.8 ± 20.4 kg) underwent treadmill exercise to voluntary exhaustion (Bruce protocol). Maximal exercise time was recorded in minutes (Tmin), and V[Combining Dot Above]O2max was simultaneously measured (M-V[Combining Dot Above]O2max, mlO2·kg·min) by an automated gas-analysis system. Athletes were then randomly divided into validation and cross-validation groups (n = 236). Linear regression yielded estimates of V[Combining Dot Above]O2max from Tmin as follows: validation V[Combining Dot Above]O2max = 4.012 × Tmin - 4.628 (r = 0.678, p < 0.001, and SEE = 4.07); cross-validation V[Combining Dot Above]O2max = 4.025 × Tmin - 4.693 (r = 0.661, p < 0.001, and SEE = -4.16). These equations had a cross-validation coefficient of 0.813 and a double cross-validation coefficient of 0.823. Differences between the slopes of the 2 equations were not significant (t-test, p = 0.9603). Because validation and cross-validation groups were not statistically different on any variables measured (multivariate analysis of variance, p > 0.05), all athletes were combined to yield our final prediction equation: football V[Combining Dot Above]O2max = 4.017 × Tmin - 4.644 (r = 0.670, p < 0.001, and SEE = 4.11). Repeated-measures analysis of variance demonstrated significant differences (p < 0.001) in estimates of V[Combining Dot Above]O2max among Foster (44.1 ± 6.1), Bruce (47.1 ± 5.5), and our football (45.1 ± 5.8) equations. Foster and Bruce V[Combining Dot Above]O2max estimates were also significantly different from M-V[Combining Dot Above]O2max ((Equation is included in full-text article.)diff = -0.975 and 1.995, respectively, p < 0.001). V[Combining Dot Above]O2max of ASF athletes can be reasonably estimated by our football prediction equation using maximal treadmill time as the predictor.

Predicting Energy Expenditure of an Acute Resistance Exercise Bout in Men and Women.

The energy expenditure of resistance exercise (RE) is an important consideration for exercise prescription and weight management, yet prediction models are lacking. PURPOSE: This study aimed to develop regression equations to predict energy expenditure (kcal) for RE involving each major muscle group using commonly measured demographic and exercise variables as predictors. METHODS: Fifty-two healthy, active subjects (27 men, 25 women, age 20-58 yr, height 174.1 ± 10.5 cm, weight 188.7 ± 42.6 kg, V˙O2max 36.8 ± 9.2 mL·kg⋅min) were strength tested to estimate their one-repetition maximum 1 wk before their experimental RE bout. The experimental RE bout consisted of a warm-up set followed by 2-3 sets (2-min turnover) of 8-12 reps at 60%-70% of predicted one-repetition maximum for leg press, chest press, leg curl, lat pull, leg extension, triceps push down, and biceps curl. Kilocalories were estimated from V˙O2 measured continuously throughout the RE bout via an automated metabolic cart. Total exercise volume (TV) was calculated as sets × reps × weight lifted. Multiple linear regression (stepwise removal) was used to determine the best model (highest adjusted R) to predict the kilocalorie consumption of the total workout and of the individual RE lifts. RESULTS: The derived regression equation for the net kilocalorie consumption of an RE bout was as follows: total net kilocalorie = 0.874 (height, cm) - 0.596 (age, yr) - 1.016 (fat mass, kg) + 1.638 (lean mass, kg) + 2.461 (TV × 10) - 110.742 (R = 0.773, SEE = 28.5 kcal). Significant equations were also derived for individual lifts (R = 0.62 to 0.83). CONCLUSIONS: Net energy expenditure for a total RE bout and for individual RE can be reasonably estimated in adult men and women using commonly measured demographic and RE variables.

An Acute Bout of Aquatic Treadmill Exercise Induces Greater Improvements in Endothelial Function and Postexercise Hypotension Than Land Treadmill Exercise: A Crossover Study.

OBJECTIVE: The purpose of the study was to compare acute bouts of aquatic treadmill (ATM) and land treadmill (LTM) exercise on flow-mediated dilation, postexercise blood pressure, plasma nitrate/nitrite, and atrial natriuretic peptide in untrained, prehypertensive men. DESIGN: In a counterbalanced, crossover design, 19 untrained, prehypertensive men completed bouts of ATM and LTM on separate days. Flow-mediated dilation was measured pre-exercise and 1-hr postexercise. Blood samples were obtained pre-exercise and immediately postexercise and analyzed for plasma nitrate/nitrite and atrial natriuretic peptide. A magnitude-based inference approach to inference was used for statistical analysis. RESULTS: A possible clinically beneficial increase in flow-mediated dilation (1.2%, 90% confidence interval = -0.07% to 2.5%) was observed 1 hr after ATM. In contrast, a possible clinically harmful decrease in flow-mediated dilation (-1.3%, 90% confidence interval = -2.7% to 0.2%) was observed 1 hr after LTM. The magnitude of the postexercise systolic blood pressure reduction was greater after ATM (-4.9, SD = 2.9 mm Hg) than LTM (-2.6, SD = 2.5 mm Hg). Atrial natriuretic peptide increased 34.3 (SD = 47.0%) after ATM and decreased -9.0 (SD = 40.0%) after LTM. CONCLUSIONS: An acute bout of ATM induced a more favorable endothelial response and greater postexercise hypotensive response than LTM. These changes were associated with increased atrial natriuretic peptide levels after ATM.

Fatty Acid Blood Levels, Vitamin D Status, Physical Performance, Activity, and Resiliency: A Novel Potential Screening Tool for Depressed Mood in Active Duty Soldiers.

This study examined whether blood fatty acid levels, vitamin D status, and/or physical activity are associated with physical fitness scores; a measure of mood, Patient Health Questionnaire-9; and a measure of resiliency, Dispositional Resiliency Scale-15 in active duty Soldiers. 100 active duty males at Fort Hood, Texas, underwent a battery of psychometric tests, anthropometric measurements, and fitness tests, and they also provided fasting blood samples for fatty acid and vitamin D analysis. Pearson bivariate correlation analysis revealed significant correlations among psychometric tests, anthropometric measurements, physical performance, reported physical inactivity (sitting time), and fatty acid and vitamin D blood levels. On the basis of these findings, a regression equation was developed to predict a depressed mood status as determined by the Patient Health Questionnaire-9. The equation accurately predicted depressed mood status in 80% of our participants with a sensitivity of 76.9% and a specificity of 80.5%. Results indicate that the use of a regression equation may be helpful in identifying Soldiers at higher risk for mental health issues. Future studies should evaluate the impact of exercise and diet as a means of improving resiliency and reducing depressed mood in Soldiers.

Exercise raises high-density lipoprotein cholesterol in men after consumption of ground beef with a high but not low monounsaturated fatty acid-saturated fatty acid ratio.

Exercise and diets with higher monounsaturated fatty acid (MUFA):saturated fatty acid (SFA) ratios are independently linked to improved blood lipid profiles, yet interactive effects in men have not been studied. We hypothesized that dietary ground beef with a high MUFA:SFA ratio (HR = 1.1) would augment the beneficial changes in the lipid profile induced by exercise compared to dietary ground beef with a lower MUFA:SFA ratio (LR = 0.71). Untrained men (n = 13, age = 35 ± 12 y, weight = 91.4 ± 14.2 kg, body mass index = 27.8 ± 3.3kg/m(2)) consumed 5 HR or LR 114 g ground beef patties weekly for 5 weeks (random order) interspersed with a 4-week self-selected (SS) washout diet. One session of exercise (70% VO2max, 1675 kJ) was completed at the end of HR and LR diets, and again after a 5-week SS diet. Diets and physical activity were otherwise not controlled. Fasting blood samples for lipid and lipoprotein analyses were obtained 30 min before and 24 h after exercise. Subjects reported no other changes in diets or physical activity patterns, and body weight and body mass index did not change over the study duration. Diet (3) × Exercise Time (2) repeated measures analysis of variance (α = .05) and follow-up analyses revealed that blood concentrations (mmol/L ± SD) of total cholesterol (5.07 ± 1.16 to 5.73 ± 1.36), high-density lipoprotein cholesterol (HDL-C) (1.19 ± 0.20 to 1.36 ± 0.29), HDL2-C (0.24 ± 0.08 to 0.28 ± 0.11), HDL3-C (0.94 ± 0.14 to 1.08 ± 0.20), and non-HDL-C (3.88 ± 1.24 to 4.37 ± 1.38) were significantly elevated with exercise after the HR beef diet, but not after LR and SS diets. Thus, in healthy, untrained men the dietary beef MUFA:SFA ratio affects the blood lipid response to a single session of aerobic exercise.

Echocardiographic and Blood Pressure Characteristics of First-Year Collegiate American-Style Football Players.

Echocardiographic (echo) and blood pressure (BP) reference values may help identify athletes at cardiovascular risk, yet benchmarks are inadequate for collegiate American-style football (ASF) players. Our purpose was to describe echo characteristics and BP values in collegiate ASF athletes compared with normal. First-year players (n = 80, age = 18 ± 1 years, height = 186 ± 7 cm, weight = 100.1 ± 22.0 kg, body mass index = 28.7 ± 5.0), body surface area [BSA] = 2.24 ± 0.25; percentage fat = 16.5 ± 9.7%) were measured for systolic and diastolic BP, and underwent echo procedures by a certified sonographer. Data analyses included simple statistics, Pearson r, frequencies in normal ranges, and t test; α = 0.05. Selected echo measurements (and indexed by BSA) were: left ventricular (LV) internal diameter diastole = 5.3 ± 0.5 cm (2.4 ± 0.3); left atrial diameter = 3.9 ± 0.5 cm (1.8 ± 0.2): LV end-diastolic volume = 138 ± 30 ml (62 ± 11); septal wall thickness = 1.0 ± 0.2 cm (0.5 ± 0.1); LV posterior wall thickness = 1.0 ± 0.1 cm (0.5 ± 0.1), LV mass = 212 ± 46 g (95 ± 18); and relative wall thickness = 0.39 ± 0.07. Correlations between BSA and echo variables were significant (r = 0.26 to 0.50). Indexing by BSA reduced percentages above reference ranges from 36% to 7%. Septal wall thickness index was significantly greater in black (0.5 ± 0.1) than nonblack (0.4 ± 0.1) athletes. Fifty-nine athletes were hypertensive or prehypertensive, and diastolic BP was significantly greater in black (76 ± 10 mm Hg) compared with nonblack athletes (71 ± 8 mm Hg). ASF athletes demonstrated LV wall thicknesses and cavity sizes consistent with sport-training hypertrophy but which were unremarkable when indexed by BSA. Ethnicity generally did not influence echo variables. No ASF players were identified with cardiac dysfunction or disease.

microRNA-16 Is Downregulated During Insulin Resistance and Controls Skeletal Muscle Protein Accretion.

Insulin resistant diabetes, currently at epidemic levels in developed countries, begins in the skeletal muscle and is linked to altered protein turnover. microRNAs downregulate targeted mRNA translation decreasing the amount of translated protein, thereby regulating many cellular processes. Regulation of miRNAs and their function in skeletal muscle insulin resistance is largely unexplored. The purpose of this study was to identify the effects of insulin resistance on contents of skeletal muscle miRNAs with potential functions in protein turnover. We examined miRs -1, -16, -23, -27, -133a, -133b, and -206 in muscles of Zucker rats. miR-1 was 5- to 10-fold greater in obesity, whereas miRs-16 and -133b were repressed ∼50% in obese compared to lean rats, with no other alterations in miRNA contents. miR-16 correlated to protein synthesis in lean, but not obese rats. miR-16 reduction by lipid overload was verified in-vivo by diet-induced obesity and in-vitro using a diacylglycerol analog. A role for miR-16 in protein turnover of skeletal myocytes was established using transient overexpression and anti-miR inhibition. miR-16 overexpression resulted in lower protein synthesis (puromycin incorporation, ∼25-50%), mTOR (∼25%), and p70S6K1 (∼40%) in starved and insulin stimulated myoblasts. Conversely, anti-miR-16 increased basal protein synthesis (puromycin incorporation, ∼75%), mTOR (∼100%), and p70S6K1 (∼100%). Autophagy was enhanced by miR-16 overexpression (∼50% less BCL-2, ∼100% greater LC3II/I, ∼50% less p62) and impaired with miR-16 inhibition (∼45% greater BCL-2, ∼25% less total LC3, ∼50% greater p62). This study demonstrates reduced miR-16 during insulin resistance and establishes miR-16 control of protein accretion in skeletal muscle. J. Cell. Biochem. 117: 1775-1787, 2016. © 2015 Wiley Periodicals, Inc.

A longitudinal study examining the effects of a season of American football on lipids and lipoproteins.

BACKGROUND: Dyslipidemia is one factor cited for increased risk of cardiovascular disease (CVD) in American football players. However, American football players undergo physical conditioning which is known to influence lipids. This study examined if the physical activity of an American football season is associated with changes in lipids and if a relationship exists between lipids and body composition. METHODS: Fourteen division I freshmen American football players had blood drawn prior to summer training (T1), end of competition (T2), and end of spring training (T3). Samples were analyzed for total cholesterol (TCHL), HDL-C, LDL-C, and triglycerides (TG). Body composition was assessed via dual-x-ray absorptiometry. National Cholesterol Education Program (NCEP) lipid categorization was used to characterize participants. Pearson correlations were computed to determine relationships. RESULTS: Body mass increased T2 (p=0.008) as a result of increase in fat mass (p=0.005) and remained high despite a decrease T3. Lean mass did not differ significantly at any time. No significant time effects were observed for lipids measured. The number of participants presenting with risk factors attributed to dyslipidemia varied. By T3, no participant was categorized as "low" for HDL-C. TCHL was moderately correlated (r=0.60) with fat mass at T1; whereas a moderate correlation (r=-0.57) was observed between BMI and HDL-C at T2. TG was strongly correlated with fat mass at each time point (T1, r=0.83; T2, r=0.94; T3, r=0.70). CONCLUSION: The physical activity associated with a season of football results in little change in blood lipids and CVD risk. Further, TG are strongly related to fat mass. Future research should focus on examining the cause of dyslipidemia in American football players.

Anabolic responses to acute and chronic resistance exercise are enhanced when combined with aquatic treadmill exercise.

Aquatic treadmill (ATM) running may simultaneously promote aerobic fitness and enhance muscle growth when combined with resistance training (RT) compared with land-treadmill (LTM) running. Therefore, we examined acute and chronic physiological responses to RT, concurrent RT-LTM, and concurrent RT-ATM. Forty-seven untrained volunteers (men: n = 23, 37 ± 11 yr, 29.6 ± 4.6 kg/m(2); women: n = 24, 38 ± 12 yr, 27.53 ± 6.4 kg/m(2)) from the general population were tested for V̇o2max, body composition, and strength before and after training. All groups performed 12 wk of RT (2 wk, 3 × 8-12 sets at 60 to approximately 80% 1-repetition maximum). The RT-LTM and RT-ATM groups also performed 12 wk of LTM or ATM training (2 wk immediately post-RT and 1 wk in isolation, 60-85% V̇o2max, 250-500 kcal/session). Additionally, 25 subjects volunteered for muscle biopsy prior to and 24 h post-acute exercise before and after training. Stable isotope labeling (70% (2)H2O, 3 ml/kg) was utilized to quantify 24 h post-exercise myofibrillar fractional synthesis rates (myoFSR). Mixed-model ANOVA revealed that RT-ATM but not RT-LTM training produced greater chronic increases in lean mass than RT alone (P < 0.05). RT-LTM training was found to elicit the greatest decreases in percent body fat (-2.79%, P < 0.05). In the untrained state, acute RT-ATM exercise elicited higher 24-h myoFSRs compared with RT (+5.68%/day, P < 0.01) and RT-LTM (+4.08%/day, P < 0.05). Concurrent RT-ATM exercise and training elicit greater skeletal muscle anabolism than RT alone or RT-LTM.

Impaired exercise-induced mitochondrial biogenesis in the obese Zucker rat, despite PGC-1α induction, is due to compromised mitochondrial translation elongation.

Previously, we demonstrated that high-volume resistance exercise stimulates mitochondrial protein synthesis (a measure of mitochondrial biogenesis) in lean but not obese Zucker rats. Here, we examined factors involved in regulating mitochondrial biogenesis in the same animals. PGC-1α was 45% higher following exercise in obese but not lean animals compared with sedentary counterparts. Interestingly, exercised animals demonstrated greater PPARδ protein in both lean (47%) and obese (>200%) animals. AMPK phosphorylation (300%) and CPT-I protein (30%) were elevated by exercise in lean animals only, indicating improved substrate availability/flux. These findings suggest that, despite PGC-1α induction, obese animals were resistant to exercise-induced synthesis of new mitochondrial and oxidative protein. Previously, we reported that most anabolic processes are upregulated in these same obese animals regardless of exercise, so the purpose of this study was to assess specific factors associated with the mitochondrial genome as possible culprits for impaired mitochondrial biogenesis. Exercise resulted in higher mRNA contents of mitochondrial transcription factor A (∼50% in each phenotype) and mitochondrial translation initiation factor 2 (31 and 47% in lean and obese, respectively). However, mitochondrial translation elongation factor-Tu mRNA was higher following exercise in lean animals only (40%), suggesting aberrant regulation of mitochondrial translation elongation as a possible culprit in impaired mitochondrial biogenesis following exercise with obesity.

Aquatic treadmill training reduces blood pressure reactivity to physical stress.

PURPOSE: Endurance exercise may reduce blood pressure and improve vasodilatory capacity, thereby blunting the hypertensive response to stress. Therefore, we sought to test the efficacy of a novel model of low-impact endurance training, the aquatic treadmill (ATM), to improve blood pressure (BP) parameters. METHODS: Sixty sedentary adults were randomized to 12-wk of either ATM (n = 36 [19 males and 17 females], 41 ± 2 yr, 173.58 ± 1.58 cm, 93.19 ± 3.15 kg) or land-based treadmill (LTM, n = 24 [11 males, 13 females], 42 ± 2 yr, 170.39 ± 1.94 cm, 88.14 ± 3.6 kg) training, three sessions per week, progressing to 500 kcal per session, 85% VO2max. The maximal Bruce treadmill test protocol was performed before and after training with BP measured before, at the end of each stage, and for 5 min after exercise testing. Twelve subjects (five ATM and seven LTM) volunteered for biopsies of the vastus lateralis before and after training, and muscle samples were assessed for endothelial nitric oxide synthase content. Data collected during exercise testing were analyzed using group by training ANCOVA repeated across training, α = 0.05. RESULTS: ATM but not LTM training significantly reduced resting diastolic BP (-3.2 mm Hg), exercise systolic BP (range 9-18.2 mm Hg lower for each exercise stage), diastolic BP (3.2-8.1 mm Hg), mean arterial pressure (4.8-8.3 mm Hg, lower than LTM posttraining), and pulse pressure (7.5-15 mm Hg) during stages of exercise stress and recovery (P < 0.05). In addition, an increase (+31%) in skeletal muscle endothelial nitric oxide synthase content after training (P < 0.05) occurred in only the ATM group. Body mass (-1.27 kg) and VO2max (+3.6 mL · kg(-1) · min(-1)) changes were significant for both groups (P < 0.001). CONCLUSION: ATM training can reduce BP reactivity to physical stress.

Exercise attenuates the increase in plasma monounsaturated fatty acids and high-density lipoprotein cholesterol but not high-density lipoprotein 2b cholesterol caused by high-oleic ground beef in women.

We hypothesized that dietary monounsaturated fatty acids (MUFA) and exercise increase high-density lipoprotein cholesterol (HDL-C) by independent mechanisms, so there would be additive effects between a single, intensive session of exercise and high-MUFA ground beef on HDL-C and blood risk factors for cardiovascular disease. Seventeen postmenopausal women completed a 2-way crossover design in which they consumed five 114-g ground beef patties per week for two 6-week periods separated by a 4-week washout (habitual diet) period. The ground beef patties contained 21% total fat with either 9.97 (low-MUFA) or 12.72 (high-MUFA) g total MUFA. Blood was taken at entry, at the end of each 6-week diet period, after the 4-week washout period, and 24 hours after aerobic exercise sessions (75% VO2peak, 2.07 MJ). After the ground beef intervention, the high-MUFA ground beef increased plasma palmitoleic acid and oleic acid, low-density lipoprotein (LDL) particle density, HDL-C, and HDL2b-C (all P < .05), whereas the low-MUFA ground beef increased LDL density. After the washout (habitual diet) period, the single exercise session increased serum LDL cholesterol, HDL-C, and HDL2a and decreased TAG and oleic acid. After the low-MUFA ground beef diet, exercise increased LDL size and HDL density and decreased LDL density and very low-density lipoprotein cholesterol, but had no effect on HDL-C fractions. After the high-MUFA ground beef intervention, exercise decreased palmitioleic acid, oleic acid, HDL-C, and HDL2a-C, but not HDL2b-C. Contrary to our hypothesis, the effects of exercise and a high-MUFA diet were not additive; instead, exercise attenuated the effects of the high-MUFA ground beef on HDL-C and plasma MUFAs. The differential effects of high-MUFA ground beef and exercise on HDL2a-C and HDL2b-C indicate that diet and exercise affect HDL-C by different mechanisms.