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1.
Eur J Clin Nutr ; 2024 Mar 07.
Article in English | MEDLINE | ID: mdl-38454153

ABSTRACT

BACKGROUND: The precision of digital anthropometry through 3-dimensional (3D) scanning has been established for relatively large, expensive, non-portable systems. The comparative performance of modern mobile applications is unclear. SUBJECTS/METHODS: Forty-six adults (age: 23.3 ± 5.3 y; BMI: 24.4 ± 4.1 kg/m2) were assessed in duplicate using: (1) a mobile phone application capturing two individual 2D images, (2) a mobile phone application capturing serial images collected during a subject's complete rotation, (3) a traditional scanner with a time of flight infrared sensor collecting visual data from a subject being rotated on a mechanical turntable, and (4) a commercial measuring booth with structured light technology using 20 infrared depth sensors positioned in the booth. The absolute and relative technical error of measurement (TEM) and intraclass correlation coefficient (ICC) for each method were established. RESULTS: Averaged across circumferences, the absolute TEM, relative TEM, and ICC were (1) 0.9 cm, 1.5%, and 0.975; (2) 0.5 cm, 0.9%, and 0.986; (3) 0.8 cm, 1.5%, and 0.974; and (4) 0.6 cm, 1.1%, and 0.985. For total body volume, these values were (1) 2.2 L, 3.0%, and 0.978; (2) 0.8 L, 1.1%, and 0.997; (3) 0.7 L, 0.9%, and 0.998; and (4) 0.8 L, 1.1%, and 0.996, with segmental volumes demonstrating higher relative errors. CONCLUSION: A 3D scanning mobile phone application involving full rotation of subjects in front of a smartphone camera exhibited similar reliability to larger, less portable, more expensive 3D scanners. In contrast, larger errors were observed for a mobile scanning application utilizing two 2D images, although the technical errors were acceptable for some applications.

2.
Nutrients ; 15(22)2023 Nov 17.
Article in English | MEDLINE | ID: mdl-38004200

ABSTRACT

Multi-ingredient thermogenic supplements can acutely increase resting energy expenditure (REE) and subjective energy. However, less is understood about the effects of chronic consumption on body composition, metabolism, and subjective variables such as mood, sleep quality, and eating behaviors. Fifty-two healthy, exercise-trained participants (50% female; mean ± SD age: 23.5 ± 3.0 years; body fat percentage: 27.3 ± 8.0%) were randomized 2:2:1 to take a whey protein supplement alone (PRO; n = 20), in combination with a thermogenic supplement (PRO + FB; n = 19), or no supplement at all (CON; n = 13) for four weeks. Body composition, anthropometric, metabolic, hemodynamic, and subjective outcomes were collected before and after the intervention. Greater changes in REE occurred in PRO + FB as compared to CON (111.2 kcal/d, 95% CI 2.4 to 219.9 kcal/d, p = 0.04), without significant differences between PRO and CON (42.7 kcal/d, 95% CI -65.0 to 150.3 kcal/d, p = 0.61) or between PRO + FB and PRO (68.5 kcal/d, 95% CI -28.3, 165.3, p = 0.21). No changes in hemodynamic outcomes (blood pressure and heart rate) were observed. In exercising adults, four weeks of supplementation with protein and a multi-ingredient thermogenic product maintained fasted REE as compared to no supplementation, for which a decrease in REE was observed, without differential effects on body composition, anthropometrics, or subjective variables.


Subject(s)
Dietary Supplements , Energy Metabolism , Adult , Humans , Female , Young Adult , Male , Body Composition , Anthropometry , Hemodynamics
3.
J Acad Nutr Diet ; 2023 Sep 22.
Article in English | MEDLINE | ID: mdl-37742826

ABSTRACT

BACKGROUND: Pre-exercise meal frequency is commonly believed to impact exercise performance, but little is known about its impact on resistance training. OBJECTIVE: This study investigated the impact of breakfast consumption on afternoon resistance training performance in habitual breakfast consumers and nonconsumers. DESIGN: A randomized, crossover study was conducted in Lubbock, TX between November 2021 and May 2022. PARTICIPANTS: Thirty-nine resistance-trained male (n = 20) and female (n = 19) adults (mean ± SD age 23.0 ± 4.7 years) who habitually consumed (≥5 d/wk; n = 19) or did not consume (≥5 d/wk; n = 20) breakfast completed the study. INTERVENTION: After the establishment of 1-repetition maximums at the first visit, participants completed 2 additional visits, each of which included 4 sets of barbell back squat, bench press, and deadlift, using 80% of their 1-repetition maximum after either consuming breakfast and lunch or the same food at lunch only. MAIN OUTCOME MEASURES: Repetitions, along with average and peak average concentric velocity and power, were measured for all repetitions throughout each exercise session. Visual analog scales were used to assess feelings of fatigue, energy, focus, hunger, desire to eat, and fullness throughout each exercise session. STATISTICAL ANALYSES PERFORMED: Data were analyzed using linear mixed-effects models. RESULTS: No interactions or main effects involving condition or habitual breakfast consumption were observed for resistance training outcomes, although sex differences were noted. Male participants performed significantly fewer repetitions on sets 2, 3, and 4 (P < .014) for total repetitions, on sets 2 and 4 for barbell back squat (P < .023), and set 4 for deadlift (P = .006), with no observed differences between sexes for bench press repetitions. Male participants displayed reductions in average power across all sets and exercises except deadlift. CONCLUSIONS: These data suggest that alterations in pre-exercise meal frequency may not influence afternoon resistance training performance provided similar total nutritional intake is consumed.

4.
J Electr Bioimpedance ; 14(1): 3-12, 2023 Jan.
Article in English | MEDLINE | ID: mdl-37416523

ABSTRACT

This study evaluated the influence of novel beverage formulations on bioimpedance- and urine-based hydration markers. Thirty young healthy adults (n=16 females, n=14 males; age: 23.2±3.7 years; BMI: 24.3±3.3 kg/m2) participated in a randomized, double-blind, placebo-controlled, crossover study. Participants completed three conditions with baseline bioimpedance, urine, and body mass assessments, followed by ingestion of one liter of a test beverage over a 30-minute period. The three beverages were: active hydration formulation in still (AFstill) or sparkling (AFspark) water and a still water control. The active formulations were identical in concentrations of alpha-cyclodextrin and complexing agents. Following beverage ingestion, bioimpedance assessments were performed every 15 minutes for two hours, followed by final urinary and body mass assessments. The primary bioimpedance outcomes were phase angle at 50 kHz, resistance of the extra-cellular compartment (R0), and resistance of the intracellular compartment (Ri). Data were analyzed using linear mixed effects models, Friedman tests, and Wilcoxon tests. Statistically significant changes in phase angle values were observed at 30 (p=0.004) and 45 minutes (p=0.024) following the initiation of beverage ingestion in the AFstill condition as compared to the reference model (i.e., control condition at baseline). Although differences between conditions were not statistically significant at later time points, the data were consistent with AFstill having greater elevations in phase angle throughout the monitoring period. At the 30-minute time point only, statistically significant differences in R0 for AFspark (p<0.001) and in Ri for AFstill (p=0.008) were observed. When averaged across post-ingestion time points, there was a trend (p=0.08) for Ri differences between conditions. The net fluid balance was greater than zero, indicating retention of ingested fluid, for AFstill (p=0.02) and control (p=0.03), with a trend for AFspark (p=0.06). In conclusion, an active formulation containing alpha-cyclodextrin in still water demonstrated potential benefits for enhancing hydration markers in humans.

5.
J Int Soc Sports Nutr ; 20(1): 2211958, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37162193

ABSTRACT

BACKGROUND: Thermogenic supplements are often consumed by individuals seeking to improve energy levels and reduce body fat. These supplements are sold in powdered or ready-to-drink (RTD) forms and consist of a blend of ingredients such as caffeine, green tea extract, and other botanical compounds. While there is evidence that thermogenic supplements can positively affect resting energy expenditure (REE), the effect varies based on the combination of active ingredients. Additionally, there is some concern that thermogenic supplements may cause unwanted side effects on hemodynamic variables, like heart rate (HR) and blood pressure (BP). Therefore, further investigation into the efficacy and safety of commercially available products is warranted. METHODS: Twenty-eight individuals (14 F, 14 M; age: 23.3 ± 3.9 yrs; height: 169.4 ± 8.6 cm; body mass: 73.3 ± 13.1 kg) completed two visits in a randomized, double-blind, crossover fashion. Each visit began with baseline REE, HR, and BP assessments, which were followed by ingestion of an active RTD thermogenic beverage (RTD; OxyShred Ultra Energy) or placebo (PL). Assessments were repeated at the intervals of 35-50- and 85-100-minutes post-ingestion. In addition, subjective outcomes of energy, focus, concentration, alertness, and mood were collected five times throughout each visit. Repeated-measures analysis of variance was performed with condition and time specified as within-subjects factors and sex and resistance training (RT) status as between-subjects factors. Statistical significance was accepted at p < 0.05. RESULTS: A significant condition × time interaction was observed for REE (p < 0.001). Higher REE values were demonstrated at 35-50 min (0.08 ± 0.02 kcal/min; p = 0.001; 5.2% difference) and 85-100 min (0.08 ± 0.02 kcal/min; p = 0.001; 5.5% difference) after RTD ingestion as compared to PL. No significant condition × time interactions were observed for respiratory quotient, HR, or BP. Condition main effects indicated lower HR (3.0 ± 0.9 bpm; p = 0.003), higher SBP (3.5 ± 1.1 mm Hg; p = 0.003) and higher DBP (3.5 ± 0.9 mm Hg; p < 0.001) in RTD as compared to PL, irrespective of time. Condition × time interactions were observed for all subjective outcomes (p ≤ 0.02). Post hoc tests indicated statistically significant benefits of the RTD over PL for energy, focus, concentration, and alertness, without significant differences for mood after correction for multiple comparisons. Sex and RT status were not involved in interactions for any outcomes, except for a Sex × RT status interaction for energy, indicating higher energy ratings in non-resistance-trained vs. resistance-trained males. CONCLUSIONS: These data suggest that acute ingestion of a thermogenic RTD beverage significantly increases REE, and this elevated caloric expenditure is sustained for at least 100 minutes following ingestion. Furthermore, the RTD beverage increased measures of energy, focus, concentration, and alertness as compared to placebo. While minor differences in hemodynamic variables were observed between conditions, all values stayed within normal ranges. Individuals aiming to increase energy expenditure may benefit from acute ingestion of an RTD thermogenic supplement.


Subject(s)
Energy Metabolism , Hemodynamics , Male , Humans , Young Adult , Adult , Blood Pressure , Heart Rate , Beverages , Double-Blind Method , Cross-Over Studies
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