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.
Alan C. Utter, David C. Nieman, Elizabeth M. Shannonhouse, Diane E. Butterworth, and Cathy N. Nieman
David M. Morris, Joshua R. Huot, Adam M. Jetton, Scott R. Collier, and Alan C. Utter
Dehydration has been shown to hinder performance of sustained exercise in the heat. Consuming fluids before exercise can result in hyperhydration, delay the onset of dehydration during exercise and improve exercise performance. However, humans normally drink only in response to thirst, which does not result in hyperhydration. Thirst and voluntary fluid consumption have been shown to increase following oral ingestion or infusion of sodium into the bloodstream. We measured the effects of acute sodium ingestion on voluntary water consumption and retention during a 2-hr hydration period before exercise. Subjects then performed a 60-min submaximal dehydration ride (DR) followed immediately by a 200 kJ performance time trial (PTT) in a warm (30 °C) environment. Water consumption and retention during the hydration period was greater following sodium ingestion (1380 ± 580 mL consumed, 821 ± 367 ml retained) compared with placebo (815 ± 483 ml consumed, 244 ± 402 mL retained) and no treatment (782 ± 454 ml consumed, 148 ± 289 mL retained). Dehydration levels following the DR were significantly less after sodium ingestion (0.7 ± 0.6%) compared with placebo (1.3 ± 0.7%) and no treatment (1.6 ± 0.4%). Time to complete the PTT was significantly less following sodium consumption (773 ± 158 s) compared with placebo (851 ± 156 s) and no treatment (872 ± 190 s). These results suggest that voluntary hyperhydration can be induced by acute consumption of sodium and has a favorable effect on hydration status and performance during subsequent exercise in the heat.
Laura Guidetti, Antonio Sgadari, Cosme F. Buzzachera, Marianna Broccatelli, Alan C. Utter, Fredric L. Goss, and Carlo Baldari
This study examined the concurrent and construct validity of the OMNI-Cycle Rating of Perceived Exertion (RPE) Scale, using elderly men and women. Seventy-six participants performed a load-incremented cycle-ergometer exercise test. Concurrent validity was determined by correlating OMNI-RPE responses with oxygen uptake, relative peak oxygen uptake, pulmonary ventilation, heart rate, respiratory rate, and respiratory-exchange ratio during a load-incremented cycle-ergometer protocol. Construct validity was established by correlating RPE derived from the OMNI-Cycle Scale with RPE from the Borg (6–20) Scale. Multilevel, mixed linear-regression models indicated that OMNI-RPE distributed as a significant (p < .05) positive linear function (r = .81–.92) for all physiological measures. OMNI-RPE was positively (p < .01) and linearly related to Borg-RPE in elderly men (r = .97) and women (r = .96). This study demonstrates both concurrent and construct validity of the OMNI-Cycle RPE Scale. These findings support the use of this scaling metric with elderly men and women to estimate RPE during cycle-ergometer exercise.
Edward E. Pistilli, David C. Nieman, Dru A. Henson, David E. Kaminsky, Alan C. Utter, Debra M. Vinci, J. Mark Davis, Omar R. Fagoaga, and Sandra L. Nehlsen-Cannarella
Immune changes in 75 younger (age 37.4 ± 0.9 years) and 23 older (57.0 ± 1.4 years) runners were compared after a competitive marathon, with blood samples collected pre- and immediately and 1.5 hr postrace. Race times were slower for the older group (4.7 ± 0.2 vs. 4.3 ± 0.1 hr, p = .015), but both groups performed at similar intensity (83.4 ± 0.9 vs. 82.9 ± 0.5% HRmax). The pattern of change in plasma cortisol, epinephrine, growth hormone, and blood leukocyte subsets did not differ significantly between the groups postrace. Blood lymphocyte counts were 20–24% lower in the older runners at each time point because of reduced T-cell counts. Postrace, plasma levels of IL-1ra, -10, -6, and -8 rose strongly in all runners, and salivary IgA secretion rate decreased, but no group differences in the pattern of change were noted. In conclusion, younger and older runners experienced similar hormonal and immune changes after running a marathon.
Richard R. Suminski, Robert J. Robertson, Fredric L. Goss, Silva Arslanian, Jie Kang, Sergio DaSilva, Alan C. Utter, and Kenneth F. Metz
Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30,60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg ly sine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.
Jie Kang, Robert J. Robertson, Bart G. Denys, Sergio G. DaSilva, Paul Visich, Richard R. Suminski, Alan C. Utter, Fredric L. Goss, and Kenneth F. Metz
This investigation determined whether carbohydrate ingestion during prolonged moderate-intensity exercise enhanced endurance performance when the exercise was preceded by carbohydrate supercompensation. Seven male trained cyclists performed two trials at an initial power output corresponding to 71 ± 1 % of their peak oxygen consumption. During the trials, subjects ingested either a 6% glucose/sucrose (C) solution or an equal volume of artificially flavored and sweetened placebo (P) every 20 min throughout exercise. Both C and P were preceded by a 6-day carbohydrate supercompensation procedure in which subjects undertook a depletion-taper exercise sequence in conjunction with a moderate- and high-carbohydrate diet regimen. Statistical analysis of time to exhaustion, plasma glucose concentration, carbohydrate oxidation rate, fat oxidation rate, and plasma glycerol concentration indicated that in spite of a carbohydrate supercompensation procedure administered prior to exercise, carbohydrate ingestion during exercise can exert an additional ergogenic effect by preventing a decline in blood glucose levels and maintaining carbohydrate oxidation during the later stages of moderate-intensity exercise.
Michael H. Stone, Kimberly Sanborn, Lucille L. Smith, Harold S. O'Bryant, Tommy Hoke, Alan C. Utter, Robert L. Johnson, Rhonda Boros, Joseph Hruby, Kyle C. Pierce, Margaret E. Stone, and Brindley Garner
The purpose of this investigation was to study the efficacy of two dietary supplements on measures of body mass, body composition, and performance in 42 American football players. Group CM (n = 9) received creatine monohy-drate, Group P (n = 11) received calcium pyruvate. Group COM (n = 11) received a combination of calcium pyruvate (60%) and creatine (40%), and Group PL received a placebo. Tests were performed before (Tl) and after (T2) the 5-week supplementation period, during which the subjects continued their normal training schedules. Compared to P and PL. CM and COM showed significantly greater increases for body mass, lean body mass, 1 repetition maximum (RM) bench press, combined 1 RM squat and bench press, and static vertical jump (SVJ) power output. Peak rate of force development for SVJ was significantly greater for CM compared to P and PL. Creatine and the combination supplement enhanced training adaptations associated with body mass/composition, maximum strength, and SVJ; however, pyruvate supplementation alone was ineffective.
Dru A. Henson, David C. Nieman, Andy D. Blodgett, Diane E. Butterworth, Alan Utter, J. Mark Davis, Gerald Sonnenfeld, Darla S. Morton, Omar R. Fagoaga, and Sandra L. Nehlsen-Cannarella
The influence of exercise mode and 6% carbohydrate (C) versus placebo (P) beverage ingestion on lymphocyte proliferation, natural killer cell cytotoxicily (NKCA), Interleukin (IL)-1ß production, and hormonal responses to 2.5 hr of intense running and cycling (~75%