Spectrum Of Physical Activity Research Articles

Physical activity and sedentary behavior show distinct associations with tissue-specific insulin sensitivity in adults with overweight.

The aim of this study is to investigate associations between the physical activity (PA) spectrum (sedentary behavior to exercise) and tissue-specific insulin resistance (IR). We included 219 participants for analysis (median [IQR]: 61 [55; 67] years, BMI 29.6 [26.9; 32.0] kg/m2 ; 60% female) with predominant muscle or liver IR, as determined using a 7-point oral glucose tolerance test (OGTT). PA and sedentary behavior were measured objectively (ActivPAL) across 7 days. Context-specific PA was assessed with the Baecke questionnaire. Multiple linear regression models (adjustments include age, sex, BMI, site, season, retirement, and dietary intake) were used to determine associations between the PA spectrum and hepatic insulin resistance index (HIRI), muscle insulin sensitivity index (MISI) and whole-body IR (HOMA-IR, Matsuda index). In fully adjusted models, objectively measured total PA (standardized regression coefficient β=0.17, p=0.020), light-intensity PA (β=0.15, p=0.045) and moderate-to-vigorous intensity PA (β=0.13, p=0.048) were independently associated with Matsuda index, but not HOMA-IR (p > 0.05). A higher questionnaire-derived sport index and leisure index were associated with significantly lower whole-body IR (Matsuda, HOMA-IR) in men but not in women. Results varied across tissues: more time spent sedentary (β=-0.24, p=0.045) and a higher leisure index (β=0.14, p=0.034) were respectively negatively and positively associated with MISI, but not HIRI. A higher sport index was associated with lower HIRI (β=-0.30, p=0.007, in men only). While we confirm a beneficial association between PA and whole-body IR, our findings indicate that associations between the PA spectrum and IR seem distinct depending on the primary site of insulin resistance (muscle or liver).

A Hunter-Gatherer Exercise Prescription to Optimize Health and Well-Being in the Modern World.

There has been considerable innovation and advancement in the field of exercise and physical activity (PA). In regards to the battle against chronic non-communicable disease, however, we believe the model of PA that would prove most salutary is one closely mimicking that of our hunter-gatherer ancestors. For the purpose of longevity, the human body and our genetic makeup have been evolutionarily adapted to respond best to moderate amounts of high-intensity interval training, in conjunction with high amounts of low intensity exercise. Moreover, to optimize resiliency and cardiorespiratory fitness, a hunter-gatherer fitness regimen must include cross training targeted at flexibility, balance and strength. Though not commonly understood, the health benefits from exercise comprise a reverse J-curve. The endurance athletes residing on the furthest reaches of the PA spectrum appear to lose a substantial portion of the exercise-related longevity and cardiovascular benefits due to cardiac overuse injury. Conversely, there is an emerging body of evidence suggesting leisure time exercise done with peers in a natural environment is significantly superior to that training done in solitude. This idea of the “power of play” lends support to the ancestral model of PA whereby humans are evolutionary adapted to be highly social, outdoor creatures capable of a diverse range of PA at varying intensities.

Abstract P321: Leisure-Time Aerobic Physical Activity Reduces the Risk of Diabetes-Related Mortality: NHANES III

Background: Evidence exists to suggest physical activity (PA) reduces risk for diabetes-related mortality (DRM). However, these studies were limited to examining specific modes of PA with only walking, running, and sports participation being consistently related to a reduced risk for DRM. Given the spectrum of leisure-time PA is inclusive of many different modes, it is important to examine this relationship using a more robust measure of PA. Purpose: To examine the relationship between leisure-time moderate-to-vigorous intensity physical activity (MVPA) and the risk of DRM in the Third National Health and Nutrition Examination Survey (1988-1994). Methods: The study sample (n=11,017) included adults, 20-79 years of age, with Mobile Examination Center (MEC) data. An age-standardized physical activity score (PAS) was calculated from the self-reported frequency and intensity of 12 leisure-time aerobic activities. PASs were then used to categorize participants into no activity (PAS = 0) versus any MVPA (PAS > 0). DRM was defined as death from diabetes mellitus, either as the primary cause or as a contributing cause in the National Death Index database. Cox Proportional Hazard models were adjusted for age, sex, race-ethnicity, education, smoking, alcohol consumption, healthy eating index, family history of diabetes, body mass index and diabetes status at the time of the MEC. Race-ethnicity specific models (i.e., non-Hispanic white, non-Hispanic black, and Mexican Americans) were also examined. Results: There was a 68% [HR=0.32 (95% CI 0.23-0.47)] reduction in the risk of DRM, adjusted for age. Following further adjustment for age, race-ethnicity, gender, education, family history of diabetes, body mass index, glycemic status, healthy eating index, smoking status, and alcohol consumption risk estimates were attenuated, but remained statistically significant [HR 0.63 (95% CI 0.43-0.93)]. No interaction between race-ethnicity and MVPA was found. Conclusions: The results of this large, nationally representative prospective study suggest that the accumulation of any volume of MVPA, across a plethora of activities, reduces the risk of DRM.