The identification of physiological loads imposed by soccer training or match play reveals essential information, which may help improve training and recovery strategies Until today, the use of heart rate (HR) monitoring is not standardized in soccer Thus, the aim of this review was to analyze, determine and compare the exercise intensity (EI) monitored by HR in professional, youth, and recreational soccer players during matches and training sessions using a meta-analysis Heart rate is one of the most common physiological variables used to determine exercise internal training load The mean EI recorded during competitive matches was described as 70-80% of VO2max or 80-90% of maximal heart rate (HRmax), independent of the playing level With respect to HR training zones, approximately 65% of the total match duration is spent at intensity of 70-90% HRmax and rarely below 65% HRmax However, although HRmax is mostly employed in the literature, monitoring EI should be expressed in relation to reserve heart rate, as it was described as a more reliable indicator of HR, allowing interindividual comparisons The HR response according to the playing position indicates that midfielders are characterized by the highest EI, followed by forwards and fullbacks Moreover, in the second half of the match, the EI is lower than that observed during the first half; this reduction could be correlated with the level of the player's physical conditioning Consequently, coaches may favor the use of interval training or small-sided training games because these are shown to improve both aerobic capacity and the ability to repeat high-intensity actions Small-sided games allow reaching similar HR responses to those found during interval training and match play but with greater heterogeneity values Future investigations should include a larger sample of players with special reference to playing position and the expression of EI in percentage of the reserve heart rate, analyzing the possible intergender differences in HR response

Heart rate monitoring in soccer: interest and limits during competitive match play and training, practical application.

Several medications have been demonstrated effective in treating individuals with attention-deficit/hyperactivity disorder (ADHD). There appears to be some commonality in the physiologic mechanisms of action of these agents relevant to the treatment of ADHD. Either direct or indirect attenuation of dopamine and norepinephrine neurotransmission appears related to both the stimulant and nonstimulant medications efficacious in ADHD. However, important differences exist both between and within the specific classes of agents. Elucidating the various mechanisms of action of ADHD medications may lead to better choices in matching potential response to the characteristics (e.g., genotype) of individuals.

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Mechanism of Action of Agents Used in Attention-Deficit/Hyperactivity Disorder

This study attempted to validate an anthropometric equation for predicting age at peak height velocity (PHV) in 198 Polish girls followed longitudinally from 8 to 18 years. Maturity offset (years before or after PHV) was predicted from chronological age, mass, stature, sitting height and estimated leg length at each observation; predicted age at PHV was the difference between age and maturity offset. Actual age at PHV for each girl was derived with Preece-Baines Model 1. Predicted ages at PHV increased from 8 to16 years and varied relative to time before and after actual age at PHV. Predicted and actual ages at PHV did not differ at 9 years, but predicted overestimated actual age at PHV from 10 to 16 years. Girls of contrasting maturity status differed in predicted age at PHV from 8 to 14 years. In conclusion, predicted age at PHV is dependent upon age at prediction and individual differences in actual age at PHV, which limits its utility as an indicator of maturity timing in general and in sport talent programmes. It may have limited applicability as a categorical variable (pre-, post-PHV) among average maturing girls during the interval of the growth spurt, ~11.0-13.0 years.

Validation of maturity offset in a longitudinal sample of Polish girls

Growth, maturation, and development dominate the daily lives of children and adolescents for approximately the first 2 decades of life. Growth and maturation are biological processes, while development is largely a behavioral process. The 3 processes occur simultaneously and interact. They can be influenced by physical activity and also can influence activity, performance, and fitness. Allowing for these potential interactions, 10 questions on growth and maturation that have relevance to physical activity, performance, and fitness are presented. The questions are not mutually exclusive and address several broadly defined topical areas: exercise and growth, body weight status (body mass index, adiposity rebound, “unhealthy weight gain”), movement proficiency (hypothesized barrier, role in obesity), individual differences, tracking, maturity-associated variation in performance, and corresponding variation in physical activity. Central to the discussion of each is the need for a biocultural approach recogniz...

The effect of acute exercise on cognitive performance in children with and without ADHD

In this study, we compared measured maximal heart rate (HRmax) to two different HRmax prediction equations [220 — age and 208 — 0.7(age)] in 52 children ages 7-17 years. We determined the relationship of chronological age, maturational age, and resting HR to measured HRmax and assessed seated resting HR and HRmax during a graded exercise test. Maturational age was calculated as the maturity offset in years from the estimated age at peak height velocity. Measured HRmax was 201 ± 10 bpm, whereas predicted HRmax ranged from 199 to 208 bpm. Measured HRmax and the predicted value from the 208 — 0.7(age) prediction were similar but lower (p < .05) than the 220 — age prediction. Absolute differences between measured and predicted HRmax were 8 ± 5 and 10 ± 8 bpm for the 208 — 0.7 (age) and 220 — age equations, respectively, and were greater than zero (p < .05). Regression equations using resting HR and maturity offset or chronological age significantly predicted HRmax, although the R2 < .30 and the standard error...

Evaluating the prediction of maximal heart rate in children and adolescents.

This study examined the effect of a single bout of exercise on measures of attention and impulsivity in children with attention deficit/hyperactivity disorder (ADHD). Children with ADHD (n = 21, 11.3 ± 1.8 yrs) and children without ADHD (n = 21, 11.6 ± 1.9 yrs) participated in the study. After performing an initial exercise test to measure peak aerobic exercise capacity, the children reported to the laboratory for 2 additional trials. For children with ADHD one trial was performed off medication and the other trial occurred on medication. During each testing session the Connor’s Continuous Performance Test II (CCPT II) was performed immediately before and after 20 minutes of intermittent exercise (30 sec exercise/30 sec rest) at 90% of peak aerobic work rate. Errors of omission, errors of commission, and reaction time (t-scores) were assessed from the CCPT II. The data were analyzed with a 3-way (group x trial x time) MANOVA. There was a significant increase in the error of omission t-score over time (pre to post exercise). There were no significant findings for the error of commission t-score. In the ADHD group the reaction time score was significantly higher than children without ADHD, significantly decreased with medication, and significantly increased over time. No other interaction or main effects were observed. Further research identifying the optimal exercise intensity and duration that can improve behavior, neurocognitive function, and academic performance is warranted.

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Acute Exercise Effects on Measures of Attention and Impulsivity in Children with Attention Deficit/Hyperactivity Disorder

Relationships between physiological parameters and 5-km running performance were examined in 15 male runners (17.3 ± 0.9 years). Running economy (RE) and blood lactate concentration ([BLa]) at 241.2 m/min, VO2max, velocity at VO2max (vVO2max), vertical jump height and muscle power, and isokinetic knee extension strength at 60°/sec and 240°/sec were measured. The participants? best 5-km race time over the last month of the cross-country season (16.98 ± 0.76 min) was used in the analysis. The data were analyzed using Pearson correlation coefficients. Significant relationships to run time were observed for VO2max (r = ?.53), RE (r = .55), and vVO2max (r = ?.66), but not [BLa], isokinetic muscle torque, or vertical jump. Identifying the unique strength and power characteristics related to running performance in this age group is warranted.

Strength, Power, and Aerobic Exercise Correlates of 5-km Cross-Country Running Performance in Adolescent Runners

The effect of stimulant medication use by children with attention deficit/hyper­activity disorder (ADHD) on the rating of perceived exertion (RPE)�heart rate (HR) relationship was examined. Children with ADHD (n = 20; 11.3 ± 1.8 yrs) and children without ADHD (n = 25; 11.2 ± 2.1 yrs) were studied. Children with ADHD were examined while on their usual dose of medication on the day of study. HR and RPE, using the OMNI RPE scale, were assessed during a graded exercise to peak voluntary effort. The RPE-HR relationship was determined individually and the intercept and slope responses were compared between groups. The inter­cept was 132.4 ± 19.5 bpm for children with ADHD and 120.6 ± 15.7 bpm for children without ADHD. The slope was 7.3 ± 1.9 bpm/RPE for the children with ADHD and 8.1 ± 1.6 bpm/ RPE for the children without ADHD. For the group with ADHD the intercept and slope values fell outside of the 95% CI observed in the control group. The altered relationship between RPE and HR with stimulant medication use in children with ADHD has practical implications with respect to the use of HR and RPE to monitor exercise intensity

Megan E. Woodruff

Papers

Evaluating the prediction of maximal heart rate in children and adolescents.

Acute Exercise Effects on Measures of Attention and Impulsivity in Children with Attention Deficit/Hyperactivity Disorder

Strength, Power, and Aerobic Exercise Correlates of 5-km Cross-Country Running Performance in Adolescent Runners

Effect of Stimulant Medication Use by Children With ADHD on Heart Rate and Perceived Exertion