Stefanie L. Rashti

Thermogenic effect of an acute ingestion of a weight loss supplement

BackgroundThe purpose of this study was to examine the acute effects of a weight loss supplement on resting oxygen uptake (VO2), respiratory quotient (RQ), caloric expenditure (kcal), heart rate (HR), and blood pressure (BP) in healthy and physically active individuals.MethodsTen subjects (5 male, 5 female; 20.2 ± 1.2 y; 172.2 ± 8.9 cm; 71.5 ± 17.2 kg; 17.3 ± 2.6% body fat) underwent two testing sessions administered in a randomized and double-blind fashion. During each session, subjects reported to the Human Performance Laboratory after at least 3-h post-absorptive state and were provided either 3 capsules of the weight loss supplement (SUP), commercially marketed as Meltdown® or 3 capsules of a placebo (P). Subjects then rested in a semi-recumbent position for three hours. VO2 and HR were determined every 5 min during the first 30 min and every 10 min during the next 150 min. BP was determined every 15 min during the first 30 min and every 30 min thereafter. The profile of mood states was assessed every 30 min.ResultsArea under the curve analysis revealed a significant 28.9% difference in VO2 between SUP and P for the three hour study period. In addition, a significant difference in energy expenditure was also seen between SUP (1.28 ± 0.33 kcal·min-1) and P (1.00 ± 0.32 kcal·min-1). A trend (p = 0.06) towards a greater utilization of stored fat as an energy source was also demonstrated (0.78 ± 0.23 kcal·min-1 and 0.50 ± 0.38 kcal·min-1 in P and SUP, respectively). Significant elevations in HR were seen during hours two and three of the study, and significantly higher average systolic BP was observed between SUP (118.0 ± 7.3 mmHg) and P (111.4 ± 8.2 mmHg). No significant differences were seen in diastolic blood pressure at any time point. Significant increases in tension and confusion were seen in SUP.ConclusionResults indicate a significant increase in energy expenditure in young, healthy individuals following an acute ingestion of a weight loss supplement. In addition, ingestion of this supplement appears modify mood and elevate HR and systolic BP following ingestion.

Effect of betaine supplementation on power performance and fatigue

BackgroundThe purpose of this study was to examine the efficacy of 15 days of betaine supplementation on muscle endurance, power performance and rate of fatigue in active college-aged men.MethodsTwenty-four male subjects were randomly assigned to one of two groups. The first group (BET; 20.4 ± 1.3 years; height: 176.8 ± 6.6 cm; body mass: 77.8 ± 13.4 kg) consumed the supplement daily, and the second group (PL; 21.4 ± 4.7 years; height: 181.3 ± 5.9 cm; body mass: 83.3 ± 5.2 kg) consumed a placebo. Subjects were tested prior to the onset of supplementation (T1) and 7 (T2) and 14 days (T3) following supplementation. Each testing period occurred over a 2-day period. During day one of testing subjects performed a vertical jump power (VJP) and a bench press throw (BPT) power test. In addition, subjects were required to perform as many repetitions as possible with 75% of their 1-RM in both the squat and bench press exercises. Both peak and mean power was assessed on each repetition. On day two of testing subjects performed two 30-sec Wingate anaerobic power tests (WAnT), each test separated by a 5-min active rest.ResultsNo differences were seen at T2 or T3 in the repetitions performed to exhaustion or in the number of repetitions performed at 90% of both peak and mean power between the groups in the bench press exercise. The number of repetitions performed in the squat exercise for BET was significantly greater (p < 0.05) than that seen for PL at T2. The number of repetitions performed at 90% or greater of peak power in the squat exercise was significantly greater for BET at both T2 and T3 than PL. No differences in any power assessment (VJP, BPT, WAnT) was seen between the groupsConclusionTwo-weeks of betaine supplementation in active, college males appeared to improve muscle endurance of the squat exercise, and increase the quality of repetitions performed.

Thermogenic effect of meltdown RTD energy drink in young healthy women: a double blind, cross-over design study.

BackgroundThe purpose of this study was to examine the acute metabolic effects of a high-energy drink in healthy, physically-active women.MethodsTen women (20.4 ± 0.70 y; 166.9 ± 7.2 cm; 67.0 ± 7.0 kg; 29.6 ± 6.5% body fat) underwent two testing sessions administered in a randomized and double-blind fashion. Subjects reported to the laboratory in a 3-hr post-absorptive state and were provided either 140 ml of the high-energy drink (SUP; commercially marketed as Meltdown RTD™) or placebo (P). Subjects consumed two 70 ml doses of SUP or P, separated by 30 min and rested in a semi-recumbent position for 3 hours. Resting oxygen consumption (VO2) and heart rate (HR) were determined every 5 min during the first 30 min and every 10 min during the next 150 min. Blood pressure (BP) was determined every 15 min during the first 30 min and every 30 min thereafter. Area under the curve (AUC) analysis was computed for VO2, whereas a 3-hour average and hourly averages were calculated for respiratory quotient (RQ), total kcal, HR, BP, and profile of mood states (POMS).ResultsAUC analysis revealed a 10.8% difference (p = 0.03) in VO2 between SUP and P. No difference in VO2 was seen between the groups in the first hour, but VO2 in SUP was significantly greater than P in the second (13.9%, p = 0.01) and third hours (11.9%, p = 0.03). A difference (p = 0.03) in energy expenditure was seen between SUP (1.09 ± 0.10 kcal·min-1) and P (0.99 ± 0.09 kcal·min-1) for the 3-hour period. Although no difference in energy expenditure was seen in the first hour, significant differences between SUP and P were observed in the second (1.10 ± 0.11 kcal·min-1 and 0.99 ± 0.09 kcal·min-1, respectively; p = 0.02) and third hour (1.08 ± 0.11 kcal·min-1 and 0.99 ± 0.09 kcal·min-1, respectively; p = 0.05). Average systolic BP was significantly higher (p = 0.007) for SUP (110.0 ± 3.9 mmHg) compared to P (107.3 ± 4.4 mmHg). No differences were seen in HR, diastolic BP, or POMS at any time point.ConclusionsResults showed a significant increase in energy expenditure in young, healthy women following an acute ingestion of a high-energy drink.

Effects of a pre- and post-exercise whey protein supplement on recovery from an acute resistance training session

Methods Fifteen male strength/power athletes volunteered to participate in this study. Subjects were randomly divided into a supplement (S; n = 7, 19.7 ± 1.5 y, 185.4 ± 3.9 cm, 96.4 ± 11.9 kg) or a placebo (P; n = 8, 20.0 ± 1.1 y, 176.7 ± 8.5 cm, 85.8 ± 12.0 kg) group. Subjects reported to the Human Performance Laboratory (HPL) on four separate occasions. On the first visit subjects were tested for maximal strength (1-RM) on the squat exercise. On their second visit (T2) subjects performed a lower body resistance exercise training session that consisted of four sets of the squat, dead lift and barbell lunge exercises. The rest interval between each set was 90 seconds. Each set was performed with 80% of the subjects previously measured 1RM. Subjects were required to perform no more than 10 repetitions for each set. The supplement (42 g of whey protein; marketed as New Whey Liquid Protein by IDS Sports, Oviedo, FL) or placebo (maltodextrin) was consumed 10 min prior to the exercise session and 15 min following the workout. Subjects then reported back to the HPL 24-(T3) and 48-hours (T4) post-exercise. During these visits subjects performed four sets of the squat exercise, using the same loading pattern and rest interval. Similar to T2, subjects consumed either the supplement or placebo before and 15 min following the exercise session. Lower body power during each squat protocol was measured with a TendoTM Power Output unit, which consists of a transducer attached to the end of the barbell measuring linear displacement and time. Both peak and mean power was recorded for each repetition.

Thermogenic effect of Meltdown RTD™ energy supplement in young healthy college women

Methods Ten female subjects (20.4 ± 0.70 y; 166.9 ± 7.2 cm; 67.0 ± 7.0 kg; 29.6 ± 6.5% body fat) underwent two testing sessions administered in a randomized and double-blind fashion. During each session, subjects reported to the Human Performance Laboratory after at least 3-h postabsorptive state and were provided either 140 ml of the high-energy supplement (S; commercially marketed as Meltdown RTD®) or placebo (P). Subjects consumed two 70 ml doses of S or P, separated by 30 min. Subjects then rested in a semi-recumbent position for three hours. VO2 and HR were determined every 5 min during the first 30 min and every 10 min during the next 150 min. BP was determined every 15 min during the first 30 min and every 30 min thereafter. The profile of mood states and questionnaire focusing on alertness, focus and fatigue was determined every 30 minutes. Area under the curve (AUC) analysis was computed for VO2, whereas a 3 hour average and an average for each hour was calculated for RQ, kcal from carbohydrate, kcal from fat, total kcal, HR, BP, and mood states. Results AUC analysis revealed a significant 10.8% difference in VO2 between S and P for the 3 hour study period. No significant differences in oxygen consumption were seen in the first hour following ingestion of the supplement. Oxygen consumption was significantly elevated within the second hour (13.9%) and third hour (11.9%) following ingestion. A significant difference in energy expenditure was also seen between S (1.09 ± 0.10 kcal·min-1) and P (0.99 ± 0.09 kcal·min-1) for the 3 hour study period. Although energy expenditure was not significantly differently different between S and P in the first hour, significant differences between the groups were seen in the second (1.10 ± 0.11 kcal·min-1 and0.99 ± 0.09 kcal·min-1, respectively), and third hour (1.08 ± 0.11 kcal·min-1 and 0.99 ± 0.09 kcal·min-1, respectively). Significantly higher systolic BP (p < 0.01) was observed between S (110.0 ± 3.9 mmHg) and P (107.3 ± 4.4 mmHg) during the three hour study period. No significant differences were seen in HR or diastolic BP at any time point. No significant differences were seen between S and P in any of the mood states measured during the study.