Modern smartphones such as the iPhone contain an integrated accelerometer, which can be used to measure body movement and estimate the volume and intensity of physical activity. Objectives: The primary objective was to assess the validity of the iPhone to measure step count and energy expenditure during laboratory-based physical activities. A further objective was to compare free-living estimates of physical activity between the iPhone and the ActiGraph GT3X+ accelerometer. Methods: Twenty healthy adults wore the iPhone 5S and GT3X+ in a waist-mounted pouch during bouts of treadmill walking, jogging, and other physical activities in the laboratory. Step counts were manually counted, and energy expenditure was measured using indirect calorimetry. During two weeks of free-living, participants (n = 17) continuously wore a GT3X+ attached to their waist and were provided with an iPhone 5S to use as they would their own phone. Results: During treadmill walking, iPhone (703 ± 97 steps) and GT3X+ (675 ± 133 steps) provided accurate measurements of step count compared with the criterion method (700 ± 98 steps). Compared with indirect calorimetry (8 ± 3 kcal·min−1), the iPhone (5 ± 1 kcal·min−1) underestimated energy expenditure with poor agreement. During free-living, the iPhone (7,990 ± 4,673 steps·day−1) recorded a significantly lower (p < .05) daily step count compared with the GT3X+ (9,085 ± 4,647 steps·day−1). Conclusions: The iPhone accurately estimated step count during controlled laboratory walking but recorded a significantly lower volume of physical activity compared with the GT3X+ during free-living.
Nicola K. Thomson, Lauren McMichan, Eilidh Macrae, Julien S. Baker, David J. Muggeridge, and Chris Easton
Krisha Parker, Daniel Czech, Trey Burdette, Jonathan Stewart, David Biber, Lauren Easton, Caitlyn Pecinovsky, Sarah Carson, and Tyler McDaniel
With over 50 million youth athletes participating in some kind of sports in the United States alone, it is important to realize the impact and benefits of playing (Weinberg and Gould, 2011). Physically, sports can help youth improve strength, endurance, weight control, and bone structure (Seefeldt, Ewing & Walk, 1992). Sport participation also benefits youths socially (Seefeldt, Ewing & Walk, 1992) and academically (Fraser-Thomas, Côté & Deakin, 2005). Optimal coaching education and training is a necessity if young athletes are to learn and improve in these aforementioned areas. In order for youth to grow from their sport experience, they need guidance from coaches, parents, and other important figures. Recent research by Jones, Jo and Martin (2007) suggests that more recent generations require a new approach to learning. The purpose of the current study was to qualitatively examine the preferred coaching styles of youth soccer players from Generation Z. After interviewing 10 youth athletes (five male, five female), four main themes emerged for Generation Z’s view of a “great coach.” These themes reflected the desire for a coach that: 1) does not yell and remains calm, 2) is caring and encouraging, 3) has knowledge of the sport, and 4) involves the team in decision making. Future research could include implementing a mixed-methodological approach incorporating the Leadership Scale for Sport (Chelladurai, 1984). Another avenue worthy of investigation is the role that technology plays for Generation Z athletes.