validity of all accelerometer placement sites and all time points. This study, while the most comprehensive to date, did not look at accuracy for specific activities nor evaluate accuracy of steps counts (instead correlating step counts to measured Calorie expenditure). Given the limited past work
Alexander H.K. Montoye, Jordana Dahmen, Nigel Campbell and Christopher P. Connolly
Buffie Longmire-Avital, Takudzwa Madzima and Elyse Bierut
high-calorie-burning (HCB) activities. HCB activities are defined as any mode of self-perceived strenuous exercise (elliptical, running, aerobics) that rapidly increases heart rate, elicits heavy breathing, and is sweaty. This type of activity, regardless of mode, falls within the range for vigorous
Alexander H.K. Montoye, John Vusich, John Mitrzyk and Matt Wiersma
Calories (kcals) ( Fitbit website, 2016 , 2017 ). Newer models have incorporated other sensors, such as altimeters (used to measure flights of stairs climbed), heart rate (HR), and activity-detection algorithms, for determining the types of activities in which wearers participate. These exciting
Laura Žlibinaitė, Rima Solianik, Daiva Vizbaraitė, Dalia Mickevičienė and Albertas Skurvydas
to a decline in brain network activity related with cognitive control regions (eg, dorsolateral prefrontal cortex [PFC]), 3 and to a decline in cognitive and motor functions. 4 – 6 Meta-analyses that examined the impact of weight loss programs comprising both exercise and calorie restriction (CR
Ben Desbrow, Katelyn Barnes, Gregory R. Cox, Elizaveta Iudakhina, Danielle McCartney, Sierra Skepper, Caroline Young and Chris Irwin
undesirable outcomes. For instance, we have recently demonstrated that ad libitum access to calorie-containing beverages (i.e., carbohydrate [CHO]-electrolyte [sports] beverages and milk-based drinks) in the laboratory increases acute energy intake (in both males and females; Campagnolo et al., 2017
Anecdotal claims have suggested that an increasing number of ultramarathoners purposely undertake chronic low-carbohydrate (CHO) ketogenic diets while training, and race with very low CHO intakes, as a way to maximize fat oxidation and improve performance. However, very little empirical evidence exists on specific fueling strategies that elite ultramarathoners undertake to maximize race performance. The study’s purpose was to characterize race nutrition habits of elite ultramarathon runners. Three veteran male ultrarunners (M ± SD; age 35 ± 2 years; mass 59.5 ± 1.7 kg; 16.7 ± 2.5 hr 100-mi. best times) agreed to complete a competition-specific nutrition intake questionnaire for 100-mi. races. Verbal and visual instructions were used to instruct the athletes on portion sizes and confirm dietary intake. Throughout 2014, the athletes competed in 16 ultramarathons with a total of 8 wins, including the prestigious Western States Endurance Run 100-miler (14.9 hr). The average prerace breakfast contained 70 ± 16 g CHO, 29 ± 20 g protein, and 21 ± 8 g fat. Athletes consumed an average of 1,162 ± 250 g of CHO (71 ± 20g/hr), with minor fat and protein intakes, resulting in caloric intakes totaling 5,530 ± 1,673 kcals (333 ± 105 kcals/hr) with 93% of calories coming from commercial products. Athletes also reported consuming 912 ± 322 mg of caffeine and 6.9 ± 2.4 g of sodium. Despite having limited professional nutritional input into their fueling approaches, all athletes practiced fueling strategies that maximize CHO intake and are congruent with contemporary evidence-based recommendations.
Nicholas J. Walters and David A. Brodie
The purpose of this study was to assess the validity of data derived from the Kenz calorie counter during progressive, incremental treadmill exercise. Direct comparisons were made with calories calculated from on-line gas analysis. The subjects were 18 adults, 18 postadolescent children, and 24 preadolescent children. Linear regression (r 2 > .95) showed a progressive deviation away from a 1:1 relationship between Kenz data and V̇O2 data with increasing age of subject which remained when standardized to kcal · kg−1 body mass or kcal · m−2 · hour−1. The Kenz calorie counter, after applying an age group correction factor, can thus be used as a suitable analog for measured energy expenditure.
Lizzy Pope, Jean Harvey-Berino, Patrick Savage, Janice Bunn, Maryann Ludlow, Neil Oldridge and Phil Ades
The acceptability of a high-calorie-expenditure (HCE) exercise program in older coronary heart disease patients participating in a behavioral weight-control program was evaluated. Seventy-four overweight patients (median age 63 yr) were randomly assigned to a 5-mo intervention of HCE exercise (3,000–3,500 kcal/wk daily walking) or standard cardiac-rehabilitation (CR) exercise (700–800 kcal/wk). Both groups received counseling to achieve a dietary caloric deficit of 3,500 kcal/ wk. Assessments at baseline and 5 mo included self-reported measures of quality of life and psychosocial variables. The HCE group experienced significantly greater weight loss (8.2 ± 4 vs. 3.7 ± 5 kg, p < .001). Changes from baseline to 5 mo on scores of physical, emotional, and social functioning were greater for the HCE than CR group (p < .05). HCE exercise also resulted in greater positive change in exercise enjoyment (p = .05), which was mediated by weight change. Even high-risk older adults can be successful in an HCE exercise program and experience no adverse physical or emotional changes.
Kelsey H. Fisher-Wellman and Richard J. Bloomer
Carbohydrate powder in the form of maltodextrin is widely used by athletes for postexercise glycogen resynthesis. There is some concern that such a practice may be associated with a postprandial rise in reactive oxygen and nitrogen species production and subsequent oxidation of macromolecules. This is largely supported by findings of increased oxidative-stress biomarkers and associated endothelial dysfunction after intake of dextrose.
To compare the effects of isocaloric dextrose and maltodextrin meals on blood glucose, triglycerides (TAG), and oxidative-stress biomarkers in a sample of young healthy men.
10 men consumed isocaloric dextrose and maltodextrin powder drinks (2.25 g/kg) in a random-order, crossover design. Blood samples were collected premeal (fasting) and at 1, 2, 4, and 6 hr postmeal and assayed for glucose, TAG, malondialdehyde, hydrogen peroxide, nitrate/nitrite, and Trolox-equivalent antioxidant capacity.
Significant meal effects were noted for glucose total area under the curve (p = .004), with values higher for the dextrose meal. No other statistically significant meal effects were noted (p > .05). With respect to the 2 (meal) × 5 (time) ANOVA, no significant interaction, time, or meal effects were noted for any variable (p > .05), with the exception of glucose, for which a main effect for both meal (p < .0001) and time (p = .0002) was noted.
These data indicate that carbohydrate meals, consumed as either dextrose or maltodextrin, pose little postprandial oxidative insult to young, healthy men. As such, there should be minimal concern over such feedings, even at high dosages, assuming adequate glucose metabolism.
Allison Naber, Whitney Lucas Molitor, Andy Farriell, Kara Honius and Brooke Poppe
). Physical activity can be objectively measured through actigraphy technology, which gathers information on an individual’s steps, calories, distance walked, and total active time ( De Rezende et al., 2014 ). Although this technology captures objective measures of physical activity, it does not provide