Date of Award

2018

Document Type

Open Access Dissertation

Department

Physical Education

Sub-Department

College of Education

First Advisor

David F. Stodden

Abstract

This dissertation consist of four studies that examine energy expenditure (EE) during object projection skill performance (OPSP). These four studies have the potential to inform physical education (PE) curricula and physical activity (PA) interventions by providing an understanding the acute EE associated with performing OPSP in developmentally appropriate activities. If OPSP is associated with high EE, then promoting their development during physical activity interventions and physical education (PE) will have both an acute and long-term health-enhancing benefit. Thus, the purposes of these four studies was to examine adult and children’s EE associated with the performance of object projection skills at different intensity intervals.

The purpose of Study 1 was to examine the metabolic cost (METS) of performing object projection skills at three practice trial intervals (6, 12 and 30 seconds). 40 adults (female n = 20) aged 18-30 (M = 23.7 ± 2.9 years) completed three, nine-minute sessions of skill trials performed at 6, 12, and 30 second intervals. Participants performed kicking, throwing and striking trials in a blocked schedule with maximal effort. Average METS during each session were measured using a COSMED K4b2. A three (interval condition) X two (sex) ANOVA was conducted to examine differences in METS across interval conditions and by sex. Data indicated a main effect for interval condition (df = 5,114, F = 187.02, p < .001, η2 = 0.76) with decreased interval times yielding significantly higher METS [30 sec = 3.45, 12 sec = 5.68, 6 sec = 8.21]. A main effect for sex (df = 5, 114, F = 35.39, p < .001, η2 = 0.24) also was found with men demonstrating higher METS across all intervals. At a rate of only two trials/min, participants elicited moderate physical activity, with 12 and 6 second intervals exhibiting vigorous PA.

The purpose of Study 2 was to compare the EE levels during OPSP as assessed by indirect calorimetry and accelerometry. Thirty-four adults (female n = 18) aged 18-30 (23.5 ± 2.5 years) performed three, nine-minute sessions of kicking, over-arm throwing, and striking performed at 6, 12, and 30 second intervals. EE was estimated (METS) using indirect calorimetry (COSMED k4b2) and hip-worn accelerometry (ActiGraph GT3X+). EE using indirect calorimetry demonstrated moderate-intensity physical activity (PA) (3.4 ± 0.7 METS – 30sec interval, 5.8 ± 1.2 METS – 12sec interval) to vigorous intensity PA (8.3 ± 1.7 METS – 6sec interval). However, accelerometry predicted EE suggested only light-intensity PA (1.7 ± 0.2 METS – 30sec interval, 2.2 ± 0.4 METS – 12sec interval, 2.7 ± 0.6 METS – 6sec interval). Accelerometry does not adequately capture the PA intensity level when performing OPSP skills, regardless of differences in performance intervals.

The purpose of Study 3 was to examine boys and girls EE during OPSP at three different intensity intervals. Children (42, Mage = 8.1) participated in a within-subjects design with three nine-minute sessions of trial intervals (i.e., 6, 12, and 30 second intervals) where participants performed kicking, throwing, and striking. Skills were performed with maximum effort in blocks of five trials of each skill in serial order until each nine-minute interval session was completed. The average metabolic equivalent of task (METS) during minutes 4-8 of each nine-minute session were calculated using a COSMED K4b2 portable gas analyzer. A 3 (interval condition) X2 (sex) ANOVA was conducted to examine differences in average METS across groups and sex. Data indicated a main effect for interval condition (df = 2, 123, F = 94.36, p < .001, η2 = 0.605). Post hoc t-tests demonstrated decreasing performance interval times yielded significantly (p < .001) and progressively higher metabolic expenditure across the three conditions (30 sec = 4.5 ± 0.8 METS, 12 sec = 6.3 ± 1.3), 6 sec = 8.3 ± 1.6). There also was a main effect for sex (df = 1, 120, F = 52.28, p < .001 η2 = 0.305). Boys demonstrated higher METS at each performance interval (p < .001). Average METS for boys and girls respectively were 9.3 (± 1.4) and 7.2 (± 1.2). METS during the six second intervals, 7.0 (± 1.1) and 5.6 (± 1.1) METS during 12 second intervals and 4.8 (± 0.7) and 4.1 (± 0.7) during 30 second intervals. Results indicate skill practice with a maximum of one trial every 30 seconds resulted in the equivalent of at least moderate physical activity (> 4.0 METS) and intervals of 6 seconds demonstrated vigorous physical activity (> 7.0 METS). These data indicate practicing/performing object projection skills, even at intervals that allow for instruction and feedback, (1 trial/30sec) is equivalent to MVPA levels in children.

The purpose of Study 4 was to compare the EE levels during OPSP as assessed by hip- and wrist-worn accelerometry in children (7-9 years). Forty-two children (female n = 20, Mage = 8.1 ± 0.8 years) performed three, nine-minute sessions of kicking, over-arm throwing, and striking at performance intervals 0f 6, 12, and 30 seconds. EE was estimated METS using indirect calorimetry (COSMED k4b2) and accelerometers (ActiGraph GT3X+) worn on three different locations (hip, dominant wrist, and non-dominant-wrists). EE using indirect calorimetry demonstrated moderate-intensity physical activity (PA; 4.5 ± 0.8 METS – 30sec interval, 6.3 ± 1.3 METS – 12sec interval) to vigorous intensity PA (8.3 ± 1.7 METS – 6sec interval). However, hip-worn accelerometry predicted EE suggested only light-intensity PA (2.4 ± 0.2 METS – 30sec interval, 2.8 ± 0.5 METS – 12sec interval, 3.4 ± 0.7 METS – 6sec interval) dominant wrist-worn accelerometry predicted EE suggested only light-intensity PA (2.8 ± 0.8 METS – 30sec interval, 3.9 ± 0.6 METS – 12sec interval, 5.2 ± 0.9 METS – 6sec interval). Accelerometry does not accurately categorize the physical activity intensity level when performing OPSP skills, regardless of differences in performance intervals or accelerometer wear location in children.

These data have the potential to significantly impact physical activity intervention strategies and the implementation of PE curricula attempting to promote moderate to vigorous PA by informing specific trial intervals which promote health-enhancing physical activity levels (i.e., MVPA). Information gleaned from this study provides evidence that the practice of OPSP can aid in the achievement (acute) of recommended health-enhancing levels of EE (i.e., MVPA), as well as promote a foundation for skill development that promotes lifelong physical activity.

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