The positive effects of physical activity on bone strength are certain. However, researchers have yet to precisely quantify the contribution of specific characteristics of physical activity that affect bone strength in children and adolescents. This commentary highlights 2 noteworthy 2017 publications that addressed osteogenic physical activity dose–response issues. Both papers moved the field forward by providing new insights on physical activity exposures beyond high-impact loading. Koedijk et al’s paper was selected because, to the best of our knowledge, it is the first systematic review to solely examine associations between sedentary behavior and indicators of bone strength. The second selected paper, Gabel et al, used novel approaches in accelerometer processing and statistical modeling to separate the osteogenic effects of frequency of short bouts of physical activity from total volume of physical activity. As such, the authors of this paper begin to explore in youth what animal models have shown for some time, that is, optimal bone adaptation requires the correct combination of intensity, frequency, duration, nonrepetitive movement, and rest. Together, these papers signal new and important approaches for the conceptualization, measurement, and interpretation of osteogenic physical activity.
Kathleen F. Janz and Fatima Baptista
Vera Ramos, Eliana V. Carraça, Teresa Paiva and Fátima Baptista
The aim of this study was to identify the best predictor of sleep quality (SQ) among physical behavior or capacity-related variables, namely physical activity, sedentary time, fitness, and physical function (activities of daily living) of independent elders using a representative sample of Portuguese aged 65 years and older (N = 437). SQ and activities of daily living were evaluated by a questionnaire, sedentary time, and physical activity through accelerometry, and physical fitness by means of the Senior Fitness Test. The logistic regression analysis revealed that activities of daily living measured by the Composite Physical Function was the only explanatory variable discriminating between poor SQ and good SQ. Receiver operating characteristic analysis showed that the best trade-off between sensitivity and specificity to discriminate older adults with poor SQ and good SQ was 20 points in the Composite Physical Function (sensitivity = 57.9%; specificity = 60.9%; area under the curve = 0.600, 95% confidence interval [0.536, 0.665], p = .003). Better physical function seems to be associated with better SQ in independent elders.
Elisa A. Marques, Fátima Baptista, Rute Santos, Susana Vale, Diana A. Santos, Analiza M. Silva, Jorge Mota and Luís B. Sardinha
This cross-sectional study was designed to develop normative functional fitness standards for the Portuguese older adults, to analyze age and gender patterns of decline, to compare the fitness level of Portuguese older adults with that of older adults in other countries, and to evaluate the fitness level of Portuguese older adults relative to recently published criterion fitness standards associated with maintaining physical independence. A sample of 4,712 independent-living older adults, age 65–103 yr, was evaluated using the Senior Fitness Test battery. Age-group normative fitness scores are reported for the 10th, 25th, 50th, 75th, and 90th percentiles. Results indicate that both women and men experience age-related losses in all components of functional fitness, with their rate of decline being greater than that observed in other populations, a trend which may cause Portuguese older adults to be at greater risk for loss of independence in later years. These newly established normative standards make it possible to assess individual fitness level and provide a basis for implementing population-wide health strategies to counteract early loss of independence.
Alon Eliakim, Bareket Falk, Neil Armstrong, Fátima Baptista, David G. Behm, Nitzan Dror, Avery D. Faigenbaum, Kathleen F. Janz, Jaak Jürimäe, Amanda L. McGowan, Dan Nemet, Paolo T. Pianosi, Matthew B. Pontifex, Shlomit Radom-Aizik, Thomas Rowland and Alex V. Rowlands
This commentary highlights 23 noteworthy publications from 2018, selected by leading scientists in pediatric exercise science. These publications have been deemed as significant or exciting in the field as they (a) reveal a new mechanism, (b) highlight a new measurement tool, (c) discuss a new concept or interpretation/application of an existing concept, or (d) describe a new therapeutic approach or clinical tool in youth. In some cases, findings in adults are highlighted, as they may have important implications in youth. The selected publications span the field of pediatric exercise science, specifically focusing on: aerobic exercise and training; neuromuscular physiology, exercise, and training; endocrinology and exercise; resistance training; physical activity and bone strength; growth, maturation, and exercise; physical activity and cognition; childhood obesity, physical activity, and exercise; pulmonary physiology or diseases, exercise, and training; immunology and exercise; cardiovascular physiology and disease; and physical activity, inactivity, and health.