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Naiman A. Khan and Charles H. Hillman

Physical inactivity has been shown to increase the risk for several chronic diseases across the lifespan. However, the impact of physical activity and aerobic fitness on childhood cognitive and brain health has only recently gained attention. The purposes of this article are to: 1) highlight the recent emphasis for increasing physical activity and aerobic fitness in children’s lives for cognitive and brain health; 2) present aspects of brain development and cognitive function that are susceptible to physical activity intervention; 3) review neuroimaging studies examining the cross-sectional and experimental relationships between aerobic fitness and executive control function; and 4) make recommendations for future research. Given that the human brain is not fully developed until the third decade of life, preadolescence is characterized by changes in brain structure and function underlying aspects of cognition including executive control and relational memory. Achieving adequate physical activity and maintaining aerobic fitness in childhood may be a critical guideline to follow for physical as well as cognitive and brain health.

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Han C.G. Kemper, Robbert Verschuur and Langha de Mey

In the Amsterdam Growth and Health Study, 103 girls and 97 boys were studied five times on a longitudinal basis over a period of 8 years, covering the teenage years from 12 to 17 until young adulthood at 22/23 years. Measured were anthropometric variables such as height, weight (BW), and body fat, and physiological variables such as maximal aerobic power (V̇O2max) and endurance performance (max slope). During the teenage period, V̇O2max/BW remains constant in boys and decreases in girls whereas endurance performance increases in boys and remains constant in girls. By young adulthood V̇O2max/BW and maximal slope have declined in both sexes, and in the case of females are even lower than at the beginning of their teens. Boys superiority in aerobic fitness and the decline in aerobic fitness in both sexes is mainly caused by the differences in the intensity of daily physical activity level.

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Carlo Castagna, Ferdinando Iellamo, Franco Maria Impellizzeri and Vincenzo Manzi

The aim of this study was to examine the reliability and validity of a popular field test for aerobic fitness used in soccer (45-15) in Italy. Alternating progressive 45-s runs with 15 s passive recovery until exhaustion, the test considers peak speed (PS) as a reflection of maximal aerobic speed (MAS). The validity and reliability of the 45-15 was assessed in 18 young male soccer players (age 16.7 ± 1.8 y, body mass 70 ± 7.45 kg, height 177 ± 0.5 cm, 55.62 ± 5.56 mL · kg−1 · min−1) submitted to laboratory testing for aerobic fitness and repeatedly to the 45-15. Results showed that 45-15 PS was significantly related to VO2max (r = .80, P < .001, 95%CI .47–.93) and MAS (r = .78, P = .001, 95%CI .43–.93). No significant bias between MAS 45-15 PS (P = .11) was found during the measurement-consistency study. Receiver-operating-characteristic (ROC) analysis showed that 45-15 PS was sensitive in detecting VO2max changes in subjects as revealed by area under the curve (.97; 95%CI .73–1). Players with peak 45-15 speed equal to or above 16.5 km/h (ie, ROC cutoff) may be considered to have good aerobic fitness. In light of this study’s findings, the 45-15 test may be considered a reliable and valid test to evaluate meaningful information to direct generic aerobic training in soccer.

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James M. Pivarnik, Wendell C. Taylor and Sharon S. Cummings

This study presents 3 years of data from a longitudinal study designed to follow changes in VO2max and treadmill (TM) exercise performance in African-American girls throughout middle school. Subjects (N = 19) were tested 6 months apart during grades 6-8. VO9 and heart rates (HR) were measured continuously while each subject performed an incremental TM test to volitional exhaustion. Absolute VO2max (ml • min1) increased with time, while relative (ml • kg 1 * min1) values declined significantly from 6th to 8th grade. Treadmill time to exhaustion improved after the first test, but showed a significant decline by the end of 8th grade. Correlations between fall 6th-grade and spring 8th-grade aerobic fitness measures ranged from .35 to .57, indicating moderate tracking of these variables throughout middle school. Aerobic fitness values are low (compared to Caucasians) in African-American adolescent girls and show significant declines throughout middle school. Future studies should investigate anatomical, physiological, and behavioral reasons for the apparently low aerobic fitness seen in African-American girls.

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Kaisu Marjut Kaikkonen, Raija irmeli Korpelainen, Mikko P. Tulppo, Hannu Sakari Kaikkonen, Marja Liisa Vanhala, Mika Antero Kallio, Sirkka M. Keinänen-Kiukaanniemi and Juha Tapani Korpelainen

Background:

Autonomic nervous system (ANS) dysfunction and obesity are intrinsically related to each other. In normal-weight subjects physical activity (PA) and fitness are related to cardiovascular autonomic regulation, providing evidence that aerobic training may improve ANS functioning measured by heart rate variability (HRV). The goal of this study was to investigate the association between lifetime PA, aerobic fitness and HRV in obese adults.

Methods:

Participants included 107 (87 females) volunteers (mean age 44.5 years, median BMI 35.7) who completed health and lifestyle questionnaires and measurements of maximal aerobic performance, anthropometry and 24 h HRV.

Results:

In the multivariate linear regression analyses, lifetime physical activity explained 40% of the variance in normal R-R intervals (SDNN). Each 1-category increase in the activity index increased SDNN by 15.4 (P = .009) and 24% of the variance in natural logarithmic value of ultra-low frequency power (P = .050). High measured VO2max explained 45% of the variance in natural logarithmic value of high-frequency power (P = .009) and 25% of the variance in low frequency/high frequency ratio (P < .001).

Conclusions:

Lifetime physical activity and aerobic fitness may reduce obesity-related health risks by improving the cardiac autonomic function measured by HRV in obese workingage subjects. This research supports the role of lifetime physical activity in weight management strategies and interventions to reduce obesity-related health risks.

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Neil Armstrong and Melitta McNarry

Peak oxygen uptake (V̇O2) is widely recognized as the criterion measure of young people’s aerobic fitness. Peak V̇O2 in youth has been assessed and documented for over 75 years but the interpretation of peak V̇O2 and its trainability are still shrouded in controversy. Causal mechanisms and their modulation by chronological age, biological maturation and sex remain to be resolved. Furthermore, exercise of the intensity and duration required to determine peak V̇O2 is rarely experienced by most children and adolescents. In sport and in everyday life young people are characterized by intermittent bouts of exercise and rapid changes in exercise intensity. In this context it is the transient kinetics of pulmonary V̇O2 (pV̇O2), not peak V̇O2, which best describe aerobic fitness. There are few rigorously determined and appropriately analyzed data from young people’s pV̇O2 kinetics responses to step changes in exercise intensity. Understanding of the trainability of pV̇O2 kinetics is principally founded on comparative studies of trained and untrained youth and much remains to be elucidated. This paper reviews peak V̇O2, pV̇O2 kinetics, and their trainability in youth. It summarizes “what we know,” identifies significant gaps in our knowledge, raises relevant questions, and indicates avenues for future research.

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Samantha M. McDonald and Stewart G. Trost

Purpose:

This study evaluated the effects of a goal setting intervention on aerobic fitness (AF) in 6th to 8th grade students.

Method:

Students at the intervention school received a lesson on SMART goal setting. Students in the comparison school served as a measurement-only group. AF was assessed via the PACER multistage shuttle run test pre and post intervention. Between-group differences for change in AF were assessed using a RM ANCOVA.

Results:

A significant group by time interaction was observed for PACER performance, F(1,263) = 39.9, p < .0001. Intervention students increased PACER performance from 40.6 to 45.9 laps, while comparison students exhibited a decline from 30.2 to 23.4 laps. Intervention students were 10 times as likely as those in the comparison school to maintain Healthy Fitness Zone status or progress from Needs Improvement Zone to Healthy Fitness Zone.

Discussion:

Educating middle school students about SMART goal setting may be an effective strategy for improving aerobic fitness.

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Patricia E. Longmuir and Roy J. Shephard

The Arm CAFT is a simple submaximal arm ergometer test for subjects with mobility disabilities, designed to match the Canadian Aerobic Fitness Test (CAFT) in both administration and interpretation. It is here evaluated relative to direct arm ergometer measurements of peak oxygen intake in 41 men and women with mobility disabilities, aged 20-60, who were attending an “integrated” sports facility. Peak oxygen intake was predicted using the original CAFT equation, but the oxygen cost of arm ergometer test stages was substituted and predictions were scaled downward by 70/100 to allow for the lower peak aerobic power of the upper limbs. In 16 subjects who maintained cranking cadence, predictions were reliable over 1 week, with a small increase of score at the second test. Although the Arm CAFT protocol is reliable and free of bias, it has only a limited validity, and only a minority of the stronger individuals with mobility disabilities can sustain the required cranking rhythm.

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George R. Biltz

In their article, Kemper and Koppes have presented their assessment of the long-term relationship between physical activity (PA) and aerobic fitness (AF). Specifically, their autoregression analysis did not support a significant causal relationship between current PA and subsequent AF as measured by VO2max. Thus, the authors question how to interpret this unexpected result. Which way does the causal arrow point between PA and AF? This reflection aims to conceptually reframe the causality question, not to resolve its behavioral or physiologic components. This reflection will explore potential sources of unexpected outcomes, analyze dimensions of cognitive difficulty in the context of exercise science, and introduce complex adaptive systems (CAS) as an alternative framework for asking questions and understanding outcomes in exercise research.

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Luiz Rodrigo Augustemak de Lima, Diego Augusto Santos Silva, Kelly Samara da Silva, Andreia Pelegrini, Isabela de Carlos Back and Edio Luiz Petroski

Purpose:

To examine aerobic fitness, total moderate to vigorous physical activity (MVPA) and also patterns in terms of MVPA between children and adolescents with human immunodeficiency virus (HIV) and controls, and to determine whether differences, if any, are associated with HIV, sex and highly active antiretroviral therapy (HAART).

Method:

A cross-sectional analysis was carried out with 130 children and adolescents, aged between 8 and 15 years, divided into two groups (HIV group= 65 patients, control group= 65 healthy participants). Total MVPA was measured by accelerometers and 5 and 10-min bouts were estimated. The peak oxygen uptake (peak VO2) was measured by breath-by-breath respiratory exchange in an incremental cycle ergometer test.

Results:

HIV-positive participants had lower peak VO2 (39.2 ± 6.8 vs. 44.5 ± 9.1 ml.kg-1min-1), lower bouts of MVPA of 5-min (19.7 ± 16.6 vs. 26.6 ± 23.5) and 10-min (3.6 ± 3.9 vs. 5.8 ± 7.2), but similar total MVPA (49.5 ± 28.9 vs. 49.1 ± 30.6 min.day-1). HIV infection in untreated, nonprotease inhibitors (PI)- based HAART and PI-based HAART patients was associated with lower 8.5 (95%CI= 12.5–4.6), 7.1 (95%CI= 10.6–3.6) and 4.5 (95%CI= 7.0–2.0) ml.kg-1min-1 of peak VO2.

Conclusion:

Children and adolescents with HIV demonstrated lower aerobic fitness compared with the controls and the absence of HAART may increase peak VO2 impairment. Lower bouts of MVPA were also observed in HIV group despite the similar values of total MVPA of controls.