Search Results

You are looking at 1 - 10 of 20 items for :

  • Author: David C. Nieman x
  • Sport and Exercise Science/Kinesiology x
Clear All Modify Search
Restricted access

Alan C. Utter, David C. Nieman, Elizabeth M. Shannonhouse, Diane E. Butterworth and Cathy N. Nieman

The purpose of this study was to measure the influence of diet, exercise, or both on body composition and cardiorespiratory fitness in obese women. Ninety-one obese subjects were randomized into one of four groups: diet (D) (4.19–5.44 MJ or 1,200–1,300 kcal/day), exercise (E) (five 45-min sessions at 78.5 ± 0.5% maximum heart rate), exercise and diet (ED), and controls (C). Maximal aerobic power and body composition were measured in all subjects before and after a 12-week diet intervention period. Subjects in D and ED lost 7.8 ± 0.7 and 8.1 ± 0.6 kg body mass, with no significant change for E relative to C. Losses of percent body fat and fat mass were significantly greater in D and ED but not in E relative to C. The change in VO2max was greater in ED and E but not D when compared to C. Results indicate that moderate aerobic exercise training during a 12-week period has no discernible effects on body composition but does improve cardiorespiratory fitness in dieting obese women.

Open access

Lindy M. Castell, David C. Nieman, Stéphane Bermon and Peter Peeling

The main focus of this review is illness among elite athletes, how and why it occurs, and whether any measures can be taken to combat it or to prevent its onset. In particular, there is particular interest in exercise-induced immunodepression, which is a result of the immune system regarding exercise (e.g., prolonged, exhaustive exercise) as a challenge to its function. This promotes the inflammatory response. There is often a high incidence of illness in athletes after undertaking strenuous exercise, particularly among those competing in endurance events, not only mainly in terms of upper respiratory tract illness, but also involving gastrointestinal problems. It may well be that this high incidence is largely due to insufficient recovery time being allowed after, for example, a marathon, a triathlon, or other endurance events. Two examples of the incidence of upper respiratory tract illness in moderate versus endurance exercise are provided. In recent years, increasing numbers of research studies have investigated the origins, symptoms, and incidence of these bouts of illness and have attempted to alleviate the symptoms with supplements, sports foods, or immunonutrition. One aspect of the present review discusses iron deficiency, which has been primarily suggested to have an impact upon cell-mediated immunity. Immunonutrition is also discussed, as are new techniques for investigating links between metabolism and immune function.

Restricted access

Alan P. Jung, David C. Nieman and Michael W. Kernodle

The purpose of this study was to validate an existing V̇O2max prediction equation for a graded cycle ergometer test, using adolescents as subjects (14). Healthy, active males (n = 19) and females (n = 19), ages 13–18 years old, pedaled at a rate of 60 rpm until exhaustion, with resistance increasing 15 W every minute. Oxygen uptake, ventilation, and respiratory exchange ratio were measured continuously. A significant correlation was found between predicted and actual V̇O2max for both male (r = 0.90, p < .001) and female (r = 0.91, p < .001) adolescents. For all subjects combined the correlation was r = 0.96, p < .001 with an SEE = 198 ml · min−1. Mean differences between actual and predicted V̇O2max values were 1.0 ± 0.7 ml · kg−1 · min−1 and 2.0 ± 0.7 ml · kg−1 · min−1 for the males and females, respectively (2.1% and 5.2% difference). The data indicate these cycle ergometry equations are valid for prediction of V̇O2max in male and female adolescents.

Restricted access

Diane E. Butterworth, David C. Nieman, Bruce C. Underwood and Kristian D. Lindsied

This study evaluated the relationship between cardiorespiratory fitness, physical activity, and dietary quality in a group of 20- to 40-year-old women (n = 34) who varied widely in levels of physical activity. Nutrient intakes were determined using 10 repeated 24-hr diet records, randomly assigned, over a 10-week period, Physical activity was determined on the same randomly assigned days using the Caltrac Personal Activity Computer. Cardiorespiratory fitness was assessed by two maximal graded treadmill tests with continuous metabolic monitoring at both the beginning and end of the 10-week period. Neither physical activity nor cardiorespiratory fitness was significantly correlated with nutrient density (nutrient/1,000 kcal). Intake of energy (kcal/kg body weight) was higher for the more physically active and fit women, leading to a significant increase in most nutrients consumed per kilogram of body weight.

Restricted access

David C. Nieman, Melanie D. Austin, Shannon M. Chilcote and Laura Benezra

The purpose of this study was to assess the validity and reliability of the MedGem™ device to measure resting metabolic rate (RMR) in children. Subjects included 59 children (29 boys, 30 girls; mean age, 11.0 ± 0.2 y). Subjects were given 4 RMR tests during 1 test session, cconsisting of 2 Douglas bag and 2 MedGem tests, in random counterbalanced order. No significant differences were found between Douglas bag and MedGem systems for oxygen consumption (209 ± 5 and 213 ± 5 mL/min, respectively, P = 0.106, r = 0.911, mean ± standard deviation absolute difference 3.72 ± 17.40 mL/min) or RMR (1460 ± 39 and 1477 ± 35 kcal/d, P = 0.286, r = 0.909, mean ± standard deviation absolute difference 17.4 ± 124 kcal/d). Standard error of estimates for oxygen consumption and RMR were 17.4 mL/min and 124 kcal/d, respectively. In conclusion, these data indicate that the MedGem is a reliable and valid system for measuring oxygen consumption and RMR in children.

Restricted access

David C. Nieman, Dru A. Henson, Steven R. McAnulty, Fuxia Jin and Kendra R. Maxwell

The purpose of this study was to test the influence of 2.4 g/d fish oil n-3 polyunsaturated fatty acids (n-3 PUFA) over 6 wk on exercise performance, inflammation, and immune measures in 23 trained cyclists before and after a 3-d period of intense exercise. Participants were randomized to n-3 PUFA (n = 11; 2,000 mg eicosapentaenoic acid [EPA], 400 mg docosahexaenoic acid [DHA]) or placebo (n = 12) groups. They ingested supplements under double-blind methods for 6 wk before and during a 3-d period in which they cycled for 3 hr/d at ~57% Wmax with 10-km time trials inserted during the final 15 min of each 3-hr bout. Blood and saliva samples were collected before and after the 6-wk supplementation period, immediately after the 3-hr exercise bout on the third day, and 14 hr postexercise and analyzed for various immune-function and inflammation parameters. Supplementation with n-3 PUFA resulted in a significant increase in plasma EPA and DHA but had no effect on 10-km time-trial performance; preexercise outcome measures; exercise-induced increases in plasma cytokines, myeloperoxidase, blood total leukocytes, serum C-reactive protein, and creatine kinase; or the decrease in the salivary IgA:protein ratio. In conclusion, 6 wk supplementation with a large daily dose of n-3 PUFAs increased plasma EPA and DHA but had no effect on exercise performance or in countering measures of inflammation and immunity before or after a 3-d period of 9 hr of heavy exertion.

Restricted access

Diane E. Butterworth, David C. Nieman, Janice V. Butler and Jodi L. Herring

A group of marathon runners (290 males, 54 females, mean age 39.7 ± 0.7 years) who participated in the Los Angeles Marathon recorded their food and fluid intake throughout a 3-day period, with the time of day denoted for each entry. Investigators coded each subject's food intake according to six time periods: 5:OO-8:59 a.m., 9:00-1059 a.m., 11:OO a.m.-1:59 p.m., 2:00-359 p.m., 4:0&7:59 p.m., and 8:00 p.m.459 a.m. The average intake of the runners consisted of 314 ± 6 g (52.3%) carbohydrates, 83.2 + 2.0 g (30.7%) fat, and 99.7 ± 2.3 g (16.5%) protein. Time periods for breakfast (13.7%), lunch (23.8%), and supper (34.0%) accounted for 71.5% of total caloric intake, with snack time periods contributing 28.5%. Breakfast calories were 68.9 ± 0.9% carbohydrate and 20.4 + 0.7% fat in contrast to supper calories, which were 47.7 ± 0.8% and 31.8 ± 0.6%, respectively. A sizable proportion of the daily caloric intake of recreational marathon runners is contributed by snacks and food intake after 4:00 p.m.

Restricted access

David C. Nieman, Courtney L. Goodman, Christopher R. Capps, Zack L. Shue and Robert Arnot

This study measured the influence of 2-weeks ingestion of high chlorogenic acid (CQA) coffee on postexercise inflammation and oxidative stress, with secondary outcomes including performance and mood state. Cyclists (N = 15) were randomized to CQA coffee or placebo (300 ml/day) for 2 weeks, participated in a 50-km cycling time trial, and then crossed over to the opposite condition with a 2-week washout period. Blood samples were collected pre- and postsupplementation, and immediately postexercise. CQA coffee was prepared using the Turkish method with 30 g lightly roasted, highly ground Hambela coffee beans in 300 ml boiling water, and provided 1,066 mg CQA and 474 mg caffeine versus 187 mg CQA and 33 mg caffeine for placebo. Plasma caffeine was higher with CQA coffee versus placebo after 2-weeks (3.3-fold) and postexercise (21.0-fold) (interaction effect, p < .001). Higher ferric reducing ability of plasma (FRAP) levels were measured after exercise with CQA coffee versus placebo (p = .01). No differences between CQA coffee and placebo were found for postexercise increases in plasma IL-6 (p = .74) and hydroxyoctadecadienoic acids (9 + 13 HODEs) (p = .99). Total mood disturbance (TMD) scores were lower with CQA coffee versus placebo (p = .04). 50-km cycling time performance and power did not differ between trials, with heart rate and ventilation higher with CQA coffee, especially after 30 min. In summary, despite more favorable TMD scores with CQA coffee, these data do not support the chronic use of coffee highly concentrated with chlorogenic acids and caffeine in mitigating postexercise inflammation or oxidative stress or improving 50-km cycling performance.

Restricted access

David C. Nieman, Courtney L. Capps, Christopher R. Capps, Zack L. Shue and Jennifer E. McBride

This double-blind, randomized, placebo-controlled crossover trial determined if ingestion of a supplement containing a tomato complex with lycopene, phytoene, and phytofluene (T-LPP) and other compounds for 4 weeks would attenuate inflammation, muscle damage, and oxidative stress postexercise and during recovery from a 2-hr running bout that included 30 min of −10% downhill running. Study participants ingested the T-LPP supplement or placebo with the evening meal for 4 weeks prior to running 2 hr at high intensity. Blood samples and delayed onset muscle soreness ratings were taken pre- and post-4-week supplementation, and immediately following the 2-hr run, and then 1-hr, 24-hr, and 48-hr postrun. After a 2-week washout period, participants crossed over to the opposite treatment and repeated all procedures. Plasma lycopene, phytoene, and phytofluene increased significantly in T-LPP compared with placebo (p < .001 for each). Significant time effects were shown for serum creatine kinase, delayed onset muscle soreness, C-reactive protein, myoglobin, 9- and 13-hydroxyoctadecadienoic acids, ferric reducing ability of plasma, and six plasma cytokines (p < .001 for each). The pattern of increase for serum myoglobin differed between T-LPP and placebo (interaction effect, p = .016, with lower levels in T-LPP), but not for creatine kinase, delayed onset muscle soreness, C-reactive protein, the six cytokines, 9- and 13-hydroxyoctadecadienoic acids, and ferric reducing ability of plasma. No significant time or interaction effects were measured for plasma-oxidized low-density lipoprotein or serum 8-hydroxy-2′-deoxyguanosine. In summary, supplementation with T-LPP over a 4-week period increased plasma carotenoid levels 73% and attenuated postexercise increases in the muscle damage biomarker myoglobin, but not inflammation and oxidative stress.

Restricted access

Beverly J. Warren, Ruth G. Dotson, David C. Nieman and Diane E. Butterworth

The accuracy of a 1-mile walking test to estimate aerobic power was assessed in a group of 28 sedentary elderly women (age = 73.5 ±0.8 yrs; body mass = 66.0 ±2.2 kg). Subjects were given the walk test and a graded maximal treadmill test for VO2peak at baseline and then were randomly assigned to either a walking group or a mild calisthenics control group for 12 weeks. Both the treadmill test and the walk test were re-administered at 5 weeks and at 12 weeks. The data suggest that regression approaches underestimate measured VO2peak by 17% in sedentary elderly women, but that accuracy is much improved after 5 weeks of brisk walking. Measurements at 12 weeks demonstrated even closer approximations of the laboratory measurement of VO2peak for the walking group. The 1-mile walk test underestimated VO2peak for the calisthenics group by 11% at the end of the 12 weeks. It was concluded that the 1-mile walk test underestimates measured VO2peak in elderly women unless they are accustomed to brisk walking.