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A total of 200,000+ large timbers were transported >75 km to Chaco Canyon, a political and religious center in the precontact U.S. Southwest, using only human power. Previous researchers reported that typical primary roof beams (vigas) of Chacoan Great Houses averaged 0.22 m in diameter and 5 m in length with a mass of 275 kg. However, the 275 kg mass appears to be a miscalculation. Here, we calculate that a ponderosa pine timber of the stated dimensions would have a mass between 85–140 kg depending on the water content. While still a prodigious load, this recalculated mass requires revisions to estimates of the labor, time, and energy required to build Great Houses at Chaco. Based on contemporary measurements on professional load carriers and soldiers, we estimate that as few as two people could have carried an 85 kg timber across 100 km in as few as 21 h of active walking. 200,000+ maderas grandes fueron transportadas >75 km hasta el Cañón del Chaco, un centro político y religioso precolombino en el suroeste de los EE.UU., utilizando únicamente fuerza humana. Investigadores anteriores informaron que las vigas principales del techo de las Casas Grandes Chacoanas tenían un diámetro promedio de 0.22 m y una longitud de 5 m con una masa de 275 kg. La masa de 275 kg parece ser un error de cálculo. Aquí, calculamos que una madera de pino ponderosa de las dimensiones indicadas tendría una masa entre 85 y 140 kg dependiendo del contenido de agua. Aunque sigue siendo una carga prodigiosa, esta masa recalculada requiere revisiones de las estimaciones de la fuerza laboral, el tiempo y la energía totales necesarios para construir las Casas Grandes en Chaco. Basado en medidas contemporáneas sobre profesionales de carga y soldados, nosotros estimamos que tan solo 2 personas podrían cargar una madera de 85 kg a través de 100 km en tan solo ∼ 21 horas de caminata activa. [ABSTRACT FROM AUTHOR]

Background: In laboratory settings, cycling workstations improve cardiometabolic risk factors. Our purpose was to quantify risk factors following a cycling intervention in the workplace. Methods: Twenty-one office workers who sat at work ≥6 hours per day underwent baseline physiological measurements (resting blood pressure, blood lipid profile, maximum oxygen consumption [...O2max], body composition, and 2-h oral glucose tolerance test). Participants were randomly assigned to a 4-week intervention only group (n = 12) or a delayed intervention group (n = 9) that involved a 4-week control condition before beginning the intervention. During the intervention, participants were instructed to use the cycling device a minimum of 15 minutes per hour, which would result in a total use of ≥2 hours per day during the workday. Following the intervention, physiological measurements were repeated. Results: Participants averaged 1.77 (0.48) hours per day of cycling during the intervention with no changes in actigraphy-monitored noncycling physical activity. Four weeks of the workplace intervention increased ...O2max (2.07 [0.44] to 2.17 [0.44] L·min-1, P < .01); end of ...O2max test power output (166.3 [42.2] to 176.6 [46.1] W, P < .01); and high-density lipoprotein cholesterol (1.09 [0.17] to 1.17 [0.24] mmol·L-1, P = .04). Conclusions: A stationary cycling device incorporated into a sedentary workplace for 4 weeks improves some cardiometabolic risk factors with no compensatory decrease in noncycling physical activity. [ABSTRACT FROM AUTHOR]