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1.
Adv Physiol Educ ; 48(3): 573-577, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38841750

RESUMEN

The East African Society of Physiological Sciences (EASPS) identified many problems associated with the practice and impact of physiology training and graduates within the region. The EASPS, in conjunction with the African Association of Physiological Sciences (AAPS), resolved to tackle those identified problems in the region by organizing a regional conference in Tanzania between November 29, 2023, and December 1, 2023. The conference was successful with remarkable achievements, including production of Physiology Curriculum for African Universities (PhysioCAFUN); launching of the International Union of Physiological Sciences (IUPS) African Physiology Mentoring Program; educational workshops on physiology teaching and skills acquisition; plenary sessions on various inspiring scientific topics for advancement of research capacities and current trends in physiological sciences; presentation of abstracts by authors and publishing of the abstracts as edited conference proceedings in the Journal of African Association of Physiological Sciences; presentation of awards to the top 10 abstracts and 7 other key Local Organizing Committee members and partners; first annual general meeting of the EASPS members; networking of participants within and beyond Africa; and recognition of the formation processes of national physiological societies in Rwanda, Kenya, Uganda, and Tanzania.NEW & NOTEWORTHY The joint East African Society of Physiological Sciences (EASPS)-African Association of Physiological Sciences (AAPS) conference in Tanzania was a successful event where we launched the Physiology Curriculum for African Universities (PhysioCAFUN) and the International Union of Physiological Sciences (IUPS) Physiology Mentoring Program in Africa. We also organized educational workshops on physiology functional tests that equipped participants with practical skills. Authors presented their peer-reviewed abstracts, which have now been published in the Journal of African Association of Physiological Sciences. Participants attended from 24 countries across Africa, Europe, Asia, and United States.


Asunto(s)
Congresos como Asunto , Fisiología , Humanos , Fisiología/educación , Tanzanía , Congresos como Asunto/tendencias , Curriculum , Investigación Biomédica/educación , Sociedades Científicas/tendencias , África Oriental
2.
J Sports Med Phys Fitness ; 64(5): 490-495, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38305005

RESUMEN

BACKGROUND: Energy availability (EA) and relative energy deficiency in sport (RED-S) are understudied in East African endurance athletes, both females (F) and males (M). This study assessed the metabolic hormonal profiles of such athletes relative to their EA status. METHODS: Forty athletes (F=16, M=24) had their EA status, training, maximal oxygen uptake, and resting blood samples assessed using standard research practices. Subjects were stratified into two groups, high EA (HiEA) and low EA (LoEA) based on combined median value. RESULTS: Cortisol (P=0.034) and insulin (P=0.044) were significantly elevated in the LoEA group, while growth hormone (P=0.045) was significantly suppressed; and, prolactin (P=0.078) trended towards suppression, respectively compared to the HiEA group. All other hormonal comparison were non-significant. CONCLUSIONS: Metabolic hormonal profiles of female and male African distance runners are affected by their EA status. Aspects of these alterations agree in part with published findings based upon White populations, although some differences exist and need further investigation.


Asunto(s)
Metabolismo Energético , Hidrocortisona , Insulina , Prolactina , Carrera , Humanos , Femenino , Masculino , Hidrocortisona/sangre , Adulto , Insulina/sangre , Carrera/fisiología , Prolactina/sangre , Metabolismo Energético/fisiología , Consumo de Oxígeno/fisiología , Deficiencia Relativa de Energía en el Deporte/sangre , Hormona de Crecimiento Humana/sangre , Adulto Joven , África Oriental , Pueblo de África Oriental
3.
Nat Metab ; 5(4): 579-588, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37100994

RESUMEN

Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.


Asunto(s)
Ejercicio Físico , Gastos en Salud , Masculino , Femenino , Estados Unidos , Humanos , Metabolismo Basal , Metabolismo Energético , Obesidad/metabolismo
4.
J Hum Evol ; 171: 103229, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36115145

RESUMEN

In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved sex differences in the degree of interindividual variation in energy expenditure. We found that, even when statistically comparing males and females of the same age, height, and body composition, there is much more variation in total, activity, and basal energy expenditure among males. However, with aging, variation in total energy expenditure decreases, and because this happens more rapidly in males, the magnitude of greater male variation, though still large, is attenuated in older age groups. Considerably greater male variation in both total and activity energy expenditure could be explained by greater male variation in levels of daily activity. The considerably greater male variation in basal energy expenditure is remarkable and may be explained, at least in part, by greater male variation in the size of energy-demanding organs. If energy expenditure is a trait that is of indirect interest to females when choosing a sexual partner, this would suggest that energy expenditure is under sexual selection. However, we present a novel energetics model demonstrating that it is also possible that females have been under stabilizing selection pressure for an intermediate basal energy expenditure to maximize energy available for reproduction.


Asunto(s)
Composición Corporal , Metabolismo Energético , Adulto , Anciano , Envejecimiento/metabolismo , Animales , Metabolismo Energético/fisiología , Femenino , Humanos , Masculino , Mamíferos , Reproducción/fisiología , Caracteres Sexuales
5.
iScience ; 25(8): 104682, 2022 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-35865134

RESUMEN

Lower ambient temperature (Ta) requires greater energy expenditure to sustain body temperature. However, effects of Ta on human energetics may be buffered by environmental modification and behavioral compensation. We used the IAEA DLW database for adults in the USA (n = 3213) to determine the effect of Ta (-10 to +30°C) on TEE, basal (BEE) and activity energy expenditure (AEE) and physical activity level (PAL). There were no significant relationships (p > 0.05) between maximum, minimum and average Ta and TEE, BEE, AEE and PAL. After adjustment for fat-free mass, fat mass and age, statistically significant (p < 0.01) relationships between TEE, BEE and Ta emerged in females but the effect sizes were not biologically meaningful. Temperatures inside buildings are regulated at 18-25°C independent of latitude. Hence, adults in the US modify their environments to keep TEE constant across a wide range of external ambient temperatures.

6.
Adv Med Educ Pract ; 13: 595-607, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35693029

RESUMEN

Background: This article presents a qualitative study of African anatomists and anatomy teachers on the Anatomage Table-a modern medical education technology and innovation, as an indicator of African anatomy medical and anatomy educators' acceptance of EdTech. The Anatomage Table is used for digital dissection, prosection, functional anatomy demonstration, virtual simulation of certain functions, and interactive digital teaching aid. Materials and Methods: Anatomy teachers [n=79] from 11 representative African countries, Ghana, Nigeria [West Africa], Ethiopia, Kenya, Rwanda [East Africa], Namibia [South Africa], Zambia [Southern Africa], Egypt [North Africa], and Sudan [Central Africa], participated in this study. Focus group discussions [FGDs] were set up to obtain qualitative information from stakeholders from representative institutions. In addition, based on the set criteria, selected education leaders and stakeholders in representative institutions participated in In-depth Interviews [IDIs]. The interview explored critical issues concerning their perceptions about the acceptance, adoption, and integration of educational technology, specifically, the Anatomage Table into the teaching of Anatomy and related medical sciences in the African continent. Recorded interviews were transcribed and analyzed using the Dedoose software. Results: African anatomists are generally technology inclined and in favor of EdTech. The most recurring opinion was that the Anatomage Table could only be a "complementary teaching tool to cadavers" and that it "can't replace the real-life experience of cadavers." Particularly, respondents from user institutions opined that it "complements the traditional cadaver-based approaches" to anatomy learning and inquiry, including being a good "complement for cadaveric skill lab" sessions. Compared with the traditional cadaveric dissections a majority also considered it less problematic regarding cultural acceptability and health and safety-related concerns. The lifelikeness of the 3D representation is a major factor that drives acceptability.

7.
Nat Commun ; 13(1): 99, 2022 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-35013190

RESUMEN

Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20-60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals >4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.


Asunto(s)
Tejido Adiposo/metabolismo , Composición Corporal/fisiología , Metabolismo Energético/fisiología , Agua/metabolismo , Adulto , Teorema de Bayes , Niño , Bases de Datos Factuales , Femenino , Humanos , Marcaje Isotópico , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Aumento de Peso/fisiología
8.
Am J Hum Biol ; 34(2): e23611, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-33988283

RESUMEN

OBJECTIVES: High trunk muscle endurance, strength, and moderate flexibility reportedly help maintain musculoskeletal health, but there is evidence for tradeoffs among these variables as well as sex differences in trunk muscle endurance and strength. To test if these observations extend similarly to both men and women in nonindustrial and industrial environments, we investigated intra-individual associations and group and sex differences in trunk muscle endurance, strength, and flexibility among 74 (35 F, 39 M; age range: 18-61 years) adults from the same Kalenjin-speaking population in western Kenya. We specifically compared men and women from an urban community with professions that do not involve manual labor with rural subsistence farmers, including women who frequently carry heavy loads. METHODS: Trunk muscle endurance, strength, and flexibility were measured with exercise tests and electromyography (EMG). RESULTS: We found a positive correlation between trunk extensor strength and endurance (R = .271, p ≤ .05) and no associations between strength or endurance and flexibility. Rural women had higher trunk extensor and flexor endurance, EMG-determined longissimus lumborum endurance, and trunk extensor strength than urban women (all p ≤ .05). Rural women had higher trunk extensor and flexor endurance than rural men (both p ≤ .05). Urban women had lower trunk flexor and extensor endurance than urban men (both p ≤ .01). CONCLUSIONS: High levels of physical activity among nonindustrial subsistence farmers, particularly head carrying among women, appear to be associated with high trunk muscle endurance and strength, which may have important benefits for helping maintain musculoskeletal health.


Asunto(s)
Agricultores , Resistencia Física , Adolescente , Adulto , Femenino , Humanos , Kenia , Masculino , Persona de Mediana Edad , Fuerza Muscular , Músculo Esquelético/fisiología , Resistencia Física/fisiología , Torso , Adulto Joven
9.
Eur J Appl Physiol ; 122(1): 199-208, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34643795

RESUMEN

PURPOSE: This study examined and compared select Triad-RED-S components/risk factors in high-level Kenyan male and female distance runners to corresponding control groups; focusing on examining energy intake (EI), bone indices, and hormonal markers. METHODS: A cross-sectional, observational design was used in which Kenyan male and female (n = 30 and n = 26, respectively) middle- and long-distance runners and corresponding male and female control groups (n = 29 and n = 29, respectively) were examined. The participant's bone mineral density (BMD) at the lumbar spine, right femur, and total body were measured using a dual-energy X-ray absorptiometry analysis. Complete blood counts (CBC) were done on the whole blood specimens and hormonal measurements were performed on plasma specimens. In addition, athletes completed metabolic testing to determine maximal oxygen uptakes and 7-day dietary diaries. RESULTS: Overall daily EI across runners and controls within each sex were low, but not significantly different (p > 0.05). Prevalence of low BMD values (Z score < - 2.0) was comparable across groups in each sex (p > 0.05). CBC measures suggested that both runners and controls were healthy. Finally, slight hormonal differences between runners and their respective controls existed (p < 0.05), but were not clinically meaningful or observed in typical Triad-RED-S-related parameters. CONCLUSION: High-level Kenyan male and female runners had low daily EI, but no tendency toward a higher prevalence of low BMD, or Triad-RED-S-related hormonal abnormalities. The occurrence of low EI was not a major risk factor in our athletes; this calls into question whether the current criteria for Triad-RED-S are entirely applicable for athletes of African ethnicity.


Asunto(s)
Atletas , Metabolismo Energético/fisiología , Deficiencia Relativa de Energía en el Deporte/epidemiología , Absorciometría de Fotón , Recuento de Células Sanguíneas , Densidad Ósea , Estudios Transversales , Ingestión de Energía , Femenino , Hormonas/sangre , Humanos , Kenia/epidemiología , Masculino , Consumo de Oxígeno , Prevalencia , Factores de Riesgo , Carrera
10.
Cureus ; 14(12): e32163, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36601205

RESUMEN

BACKGROUND: The Anatomage Table is a modern technology that is used to enhance the teaching of human anatomy and related basic medical sciences to medical and allied health students. Its use is gaining popularity. This study considered anatomy teachers' perception and acceptance of the Anatomage Table technology and digital teaching materials in the training of medical and allied health students in African countries. MATERIALS AND METHODS: Validated questionnaires were used. Altogether, 79 respondents fully participated in the study, with all African regions being represented as follows: Ghana, Nigeria (West Africa), Ethiopia Kenya Rwanda (East Africa), Namibia, South Africa, Zambia (Southern Africa), Egypt (North Africa), and Sudan (Central Africa). Responses were obtained from the electronic Google form, organized on Excel spreadsheets, and analyzed using the SPSS statistical software version 23.0 (IBM Corp, Armonk, NY). RESULTS: In terms of proportion, 29.1% of respondents reported that they had some level of mastery in using the Anatomage Table; with 6.3% of all the participants reportedly having a high mastery of this technology, 12% and 6% reported that they had an average mastery and low mastery levels, respectively. Participants' rating of their level of agreement with whether the Anatomage Table is a useful EdTech showed that 54.4% of them strongly agreed while 27.8% just agreed. The majority considered the use of the Anatomage as a means of embracing the global culture of technology-in-medical sciences (87.3%). CONCLUSION: Most respondents would accept the technology as a complementary tool to support the existing traditional practices, especially cadaveric.

12.
Am J Clin Nutr ; 114(5): 1583-1589, 2021 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-34477824

RESUMEN

BACKGROUND: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass. OBJECTIVES: A study is presented of the association between FFM and physical activity in relation to age. METHODS: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution. RESULTS: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males < 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants < 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively. CONCLUSIONS: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults.


Asunto(s)
Tejido Adiposo/metabolismo , Composición Corporal , Ejercicio Físico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Estudios Transversales , Metabolismo Energético , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
13.
ACR Open Rheumatol ; 3(11): 765-770, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34448545

RESUMEN

OBJECTIVE: Previous studies have demonstrated that low physical activity levels during youth are associated with the development of thin knee cartilage, which may increase susceptibility to osteoarthritis later in life. Here, we propose and test the hypothesis that reductions in physical activity impair knee cartilage growth among people in developing countries experiencing urbanization and increased market integration. METHODS: Ultrasonography was used to measure knee cartilage thickness in 168 children and adolescents (aged 8-17 years) from two groups in western Kenya: a rural, physically active group from a small-scale farming community and an urban, less physically active group from the nearby city of Eldoret. We used general linear models to assess the relative effects of age on cartilage thickness in these two groups, controlling for sex and leg length. RESULTS: Both groups exhibited significant reductions in knee cartilage thickness with increasing age (P < 0.0001; 95% confidence interval [CI] 0.15-0.06 mm), yet the rate of reduction was significantly less in the rural than in the urban group (P = 0.012; 95% CI 0.01-0.10 mm). CONCLUSION: The results support our hypothesis by showing that individuals from the more physically active rural group exhibited less knee cartilage loss during youth than the more sedentary urban group. Our findings suggest that reduced physical activity associated with urbanization in developing nations may affect adult knee cartilage thickness and thus could be a factor that increases susceptibility to osteoarthritis.

14.
Curr Biol ; 31(20): 4659-4666.e2, 2021 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-34453886

RESUMEN

Understanding the impacts of activity on energy balance is crucial. Increasing levels of activity may bring diminishing returns in energy expenditure because of compensatory responses in non-activity energy expenditures.1-3 This suggestion has profound implications for both the evolution of metabolism and human health. It implies that a long-term increase in activity does not directly translate into an increase in total energy expenditure (TEE) because other components of TEE may decrease in response-energy compensation. We used the largest dataset compiled on adult TEE and basal energy expenditure (BEE) (n = 1,754) of people living normal lives to find that energy compensation by a typical human averages 28% due to reduced BEE; this suggests that only 72% of the extra calories we burn from additional activity translates into extra calories burned that day. Moreover, the degree of energy compensation varied considerably between people of different body compositions. This association between compensation and adiposity could be due to among-individual differences in compensation: people who compensate more may be more likely to accumulate body fat. Alternatively, the process might occur within individuals: as we get fatter, our body might compensate more strongly for the calories burned during activity, making losing fat progressively more difficult. Determining the causality of the relationship between energy compensation and adiposity will be key to improving public health strategies regarding obesity.


Asunto(s)
Adiposidad , Obesidad , Ingestión de Energía , Metabolismo Energético/fisiología , Humanos , Obesidad/metabolismo
15.
Science ; 373(6556): 808-812, 2021 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-34385400

RESUMEN

Total daily energy expenditure ("total expenditure") reflects daily energy needs and is a critical variable in human health and physiology, but its trajectory over the life course is poorly studied. We analyzed a large, diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 years. Total expenditure increased with fat-free mass in a power-law manner, with four distinct life stages. Fat-free mass-adjusted expenditure accelerates rapidly in neonates to ~50% above adult values at ~1 year; declines slowly to adult levels by ~20 years; remains stable in adulthood (20 to 60 years), even during pregnancy; then declines in older adults. These changes shed light on human development and aging and should help shape nutrition and health strategies across the life span.


Asunto(s)
Envejecimiento , Metabolismo Energético , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Metabolismo Basal , Composición Corporal , Peso Corporal , Niño , Preescolar , Ejercicio Físico , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Embarazo , Adulto Joven
16.
J Strength Cond Res ; 35(2): 481-486, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29952871

RESUMEN

ABSTRACT: Mooses, M, Haile, DW, Ojiambo, R, Sang, M, Mooses, K, Lane, AR, and Hackney, AC. Shorter ground contact time and better running economy: evidence from female Kenyan runners. J Strength Cond Res 35(2): 481-486, 2021-Previously, it has been concluded that the improvement in running economy (RE) might be considered as a key to the continued improvement in performance when no further increase in V̇o2max is observed. To date, RE has been extensively studied among male East African distance runners. By contrast, there is a paucity of data on the RE of female East African runners. A total of 10 female Kenyan runners performed 3 × 1,600-m steady-state run trials on a flat outdoor clay track (400-m lap) at the intensities that corresponded to their everyday training intensities for easy, moderate, and fast running. Running economy together with gait characteristics was determined. Subjects showed moderate to very good RE at the first (202 ± 26 ml·kg-1·km-1) and second (188 ± 12 ml·kg-1·km-1) run trials, respectively. Correlation analysis revealed significant relationship between ground contact time (GCT) and RE at the second run (r = 0.782; p = 0.022), which represented the intensity of anaerobic threshold. This study is the first to report the RE and gait characteristics of East African female athletes measured under everyday training settings. We provided the evidence that GCT is associated with the superior RE of the female Kenyan runners.


Asunto(s)
Consumo de Oxígeno , Carrera , Femenino , Marcha , Kenia , Masculino
17.
Nature ; 571(7764): 261-264, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31243365

RESUMEN

Until relatively recently, humans, similar to other animals, were habitually barefoot. Therefore, the soles of our feet were the only direct contact between the body and the ground when walking. There is indirect evidence that footwear such as sandals and moccasins were first invented within the past 40 thousand years1, the oldest recovered footwear dates to eight thousand years ago2 and inexpensive shoes with cushioned heels were not developed until the Industrial Revolution3. Because calluses-thickened and hardened areas of the epidermal layer of the skin-are the evolutionary solution to protecting the foot, we wondered whether they differ from shoes in maintaining tactile sensitivity during walking, especially at initial foot contact, to improve safety on surfaces that can be slippery, abrasive or otherwise injurious or uncomfortable. Here we show that, as expected, people from Kenya and the United States who frequently walk barefoot have thicker and harder calluses than those who typically use footwear. However, in contrast to shoes, callus thickness does not trade-off protection, measured as hardness and stiffness, for the ability to perceive tactile stimuli at frequencies experienced during walking. Additionally, unlike cushioned footwear, callus thickness does not affect how hard the feet strike the ground during walking, as indicated by impact forces. Along with providing protection and comfort at the cost of tactile sensitivity, cushioned footwear also lowers rates of loading at impact but increases force impulses, with unknown effects on the skeleton that merit future study.


Asunto(s)
Callosidades/fisiopatología , Pie/patología , Pie/fisiología , Dolor/fisiopatología , Tacto/fisiología , Caminata/fisiología , Adulto , Boston , Callosidades/patología , Femenino , Fricción/fisiología , Dureza/fisiología , Humanos , Kenia , Masculino , Persona de Mediana Edad , Estimulación Física , Presión , Zapatos , Fenómenos Fisiológicos de la Piel , Soporte de Peso/fisiología , Adulto Joven
18.
Obesity (Silver Spring) ; 26(3): 522-530, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29464908

RESUMEN

OBJECTIVE: Assortative mating for adiposity increases the genetic burden on offspring, but its causes remain unclear. One hypothesis is that people who have high adiposity find other people with obesity more physically attractive than lean people. METHODS: The attractiveness of sets of images of males and females who varied in adiposity were rated by opposite sex subjects (559 males and 340 females) across 12 countries. RESULTS: There was tremendous individual variability in attractiveness ratings. For female attractiveness, most males favored the leanest subjects, but others favored intermediate fatness, some were indifferent to body composition, and others rated the subjects with obesity as most attractive. For male images rated by females, the patterns were more complex. Most females favored subjects with low levels of adiposity (but not the lowest level), whereas others were indifferent to body fatness or rated the images depicting individuals with obesity as the most attractive. These patterns were unrelated to rater BMI. Among Caucasian males who rated the images of the thinnest females as being more attractive, the magnitude of the effect depended on rater BMI, indicating limited "mutual attraction." CONCLUSIONS: Individual variations in ratings of physical attractiveness were broadly unrelated to rater BMI and suggest that mutual attraction is an unlikely explanation for assortative mating for obesity.


Asunto(s)
Belleza , Índice de Masa Corporal , Obesidad/psicología , Adulto , Femenino , Identidad de Género , Humanos , Masculino
19.
Am J Hum Biol ; 28(4): 514-23, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26707057

RESUMEN

OBJECTIVES: To study the effects of urbanization on physical fitness (PF), we compare PF between urban and rural children from western Kenya. We hypothesize that active rural children are stronger, more flexible, and have greater endurance, and that PF differences are predictive of endurance running performance. METHODS: We recruited an age-matched, cross-sectional sample of participants (55 males, 60 females; 6-17 years) from schools near Eldoret, Kenya. PF and anthropometrics were assessed using the FITNESSGRAM®. General linear mixed models (GLMM) and path analyses tested for age, sex, and activity group differences in PF, as well as the effects of PF variables on mile run time. RESULTS: On average, urban participants had greater body mass (36.8 ± 15.9 vs. 31.9 ± 10.9 kg) but were not taller than rural participants (1.4 ± 0.2 vs. 1.4 ± 0.2 cm). Greater urban body mass appears driven by higher body fat (28.2 ± 9.4 vs. 16.8 ± 4.4%), which increased with age in urban but not rural participants. GLMM analyses showed age effects on strength variables (P<0.05) and sex differences in hip flexibility, sit-ups, and mile run (P<0.05). There were few differences in PF between groups except rural participants had stronger back muscles (18.2 ± 4.5 vs. 14.18 ± 4.3 cm) and faster mile times (6.3 ± 0.7 vs. 7.9 ± 2.0 min). Body composition and abdominal strength were predictive of mile time (P < 0.06), but the path analysis revealed a network of interacting direct and indirect effects that influenced endurance performance. CONCLUSIONS: Although differences in endurance and body composition are marked between urban and rural groups, strength and flexibility are not always correlated with overall activity levels. Am. J. Hum. Biol. 28:514-523, 2016. © 2015 Wiley Periodicals, Inc.


Asunto(s)
Composición Corporal , Fuerza Muscular , Aptitud Física , Rango del Movimiento Articular , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Kenia , Masculino , Población Rural , Población Urbana
20.
Glob Health Promot ; 23(4): 73-75, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25921431

RESUMEN

Humans evolved for active lifestyles involving hunting-gathering and agriculture. To sustain these energy-intensive lifestyles, diets consisting of energy-dense foods were selected. It can therefore be argued that humans are physiologically adapted for active lifestyles. However, with rapid industrialisation, there has been an upsurge in the usage of labour-saving devices as well as a glut in the supply of energy-dense foods. This mismatch between energy supply and expenditure in modern man may be fuelling the contemporary trends in obesity in urbanised man. On the other hand, recent emerging evidence indicates that air pollution related to motorised transportation in urban areas may be obesogenic by causing alterations in the lipid metabolic pathways, resulting in fat deposition. These lifestyle shifts are drastically different from traditional rural African lifestyles and mirror the different prevalence rates of obesity and related co-morbidities between rural versus urban areas.


Asunto(s)
Obesidad/epidemiología , Obesidad/etiología , África del Sur del Sahara/epidemiología , Contaminantes Atmosféricos/efectos adversos , Humanos , Estilo de Vida , Factores de Riesgo , Población Urbana/estadística & datos numéricos
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