Age, muscle fatigue, and walking endurance in pre-menopausal women

Aging is associated with loss of endurance; however, aging is also associated with decreased fatigue during maximal isometric contractions. The aims of this study were to examine the relationship between age and walking endurance (WE) and maximal isometric fatigue (MIF) and to determine which metabolic/fitness components explain the expected age effects on WE and MIF. Subjects were 96 pre-menopausal women. Oxygen uptake (walking economy) was assessed during a 3-mph walk; aerobic capacity and WE by progressive treadmill test; knee extension strength by isometric contractions, MIF during a 90-s isometric plantar flexion (muscle metabolism measured by 31P MRS). Age was related to increased walking economy (low VO2, r = −0.19, P < 0.03) and muscle metabolic economy (force/ATP, 0.34, P = 0.01), and reduced MIF (−0.26, P < 0.03). However, age was associated with reduced WE (−0.28, P < 0.01). Multiple regression showed that muscle metabolic economy explained the age-related decrease in MIF (partial r for MIF and age −0.13, P = 0.35) whereas walking economy did not explain the age-related decrease in WE (partial r for WE and age −0.25, P < 0.02). Inclusion of VO2max and knee endurance strength accounted for the age-related decreased WE (partial r for WE and age = 0.03, P > 0.80). In premenopausal women, age is related to WE and MIF. In addition, these results support the hypothesis that age-related increases in metabolic economy may decrease MIF. However, decreased muscle strength and oxidative capacity are related to WE.

Narratives of the 'everyday' in Rio de Janeiro's favelas : community photographers' attempts at generating alternative news values [Narrativas do cotidiano nas favelas do Rio de Janeiro: tentativas de construção de valores-notícia alternativos pelos fotógrafos populares]

Abstract This paper presents the partial results of an ongoing research project which investigates ethnographically community (photo)journalism media initiatives, in Rio de Janeiro, Brazil. The Viva Rio and Observatorio de Favelas (NGOs) run projects that provide favela residents with skills to take, edit and print their own (photo) journalism contents that enables community-based framing and documentation of favela live, personalities and issues. Three months of fieldwork related to these projects in Rio's favelas generated remarkable theoretical issues that represent the community photographers' attempt to establish counter news values by shifting the focus from poverty, shortages, violence and criminality to images of the ordinary life which included the myriad events that occurs in the day of the favelas. Resumo Este artigo apresenta os resultados parciais de uma pesquisa em andamento que, a partir do método etnográfico, investiga os projetos de comunicação comunitária, jornalismo e fotojornalismo, no Rio de Janeiro, Brasil. As organizações não-governamentais (ONGs) Viva Rio e Observatório de Favela apoiam projetos que objetivam tornar moradores de favelas capazes de produzir, editar e publicar as suas próprias narrativas sobre personagens e questões do cotidiano de suas comunidades. O trabalho de campo sobre estes projetos, realizado durante três meses nas favelas do Rio de Janeiro, forneceu questões teóricas relevantes que representam o esforço dos fotógrafos populares para estabelecer contra valores-notícia transferindo o foco da pobreza, escassez, violência e criminalidade para imagens do cotidiano que inclui uma miríade de eventos que acontecem no dia-a-dia das favelas.