Health-related physical fitness: Status of body composition, musculoskeletal- and neuromotor fitness, and the e ect of a tailored, telephone and email based exercise intervention on body composition and physical fitness

Background: The increasing obesity prevalence rates in addition to the increasing physical inactivity rates present serious public health challenges worldwide. The effect of these trends on aspects of health-related physical fitness is unclear as these trends are most commonly assessed by selfreport or simpler objective measures. Up-to-date research on obesity prevalence rates and musculoskeletal- and neuromotor fitness by various well established and objectively measures is lacking. Additionally, the need interventions aiming at reducing both the prevalence of physical inactivity in addition to the prevalence of obesity has been highlighted. Tailored physical activity interventions delivered in alternative technological modes have proven effective in enhancing physical activity levels in adults, however the effect of such interventions on objetively measured aspects of health-related physical fitness among physically inactive adults is lacking. Purpose: The overall purpose of this thesis was to investigate the status of various aspects of healthrelated physical fitness and to assess the effect of a six-month tailored telephone- and email based exercise intervention on various aspects of health-related physical fitness. Methods: The results presented in this thesis are based on two separate studies; a national cross-sectional study of Norwegian adults (20-65 years) (PAPERS I and II) and elderly (65-85 years) (PAPER I) in addition to a randomized controlled trial of a six-month tailored exercise intervention in physically inactive adults (40-55 years) (Papers III and IV). Main results: The main results from PAPER I revealed that obesity prevalence rates ranging from 12.7% based on BMI measures to 30.9% based on waist circumference. The sensitivity and specificity of the different measuring methods for estimating overweight and obesity, varied from 77.0% to 86.9% and from 60.6% to 82.3%, respectively. The main results from PAPER II were the normative data on musculoskeletal- and neuromotor fitness, displaying clear gender (p<0.001) and age related (p≤0.044) differences. Females displayed significantly higher scores on muscular endurance of the back extensors and on the flexibility tests (p < 0.001), while males displayed significantly higher scores on muscular strength, muscular dynamic endurance and ability to stabilize the upper body, as well as explosive power (p < 0.001). Additionally, younger participants displayed higher test scores on all musculoskeletal- and neuromotor fitness tests, compared to older participants (Females; Beta:−0.06–(−0.92), p ≤ 0.044, Males; Beta:−0.15–(0.91), p ≤ 0.006). Furthermore, waist circumference was inversely related to many aspects of musculoskeletal- and neuromotor fitness (p < 0.001).The main findings from PAPER III and PAPER IV revealed significant improvements in test scores on maximal oxygen consumption (VO2max, ml/kg/min) (ES:0.12, p=0.002), muscular endurance of the back extensors (ES:0.21, p