Automatic Detection of Aerobic Threshold through Recurrence Quantification Analysis of Heart Rate Time Series

During exercise with increasing intensity, the human body transforms energy with mechanisms dependent upon actual requirements. Three phases of the body’s energy utilization are recognized, characterized by different metabolic processes, and separated by two threshold points, called aerobic (AerT) and anaerobic threshold (AnT). These thresholds occur at determined values of exercise intensity(workload) and can change among individuals. They are considered indicators of exercise capacities and are useful in the personalization of physical activity plans. They are usually detected by ventilatory or metabolic variables and require expensive equipment and invasive measurements. Recently, particular attention has focused on AerT, which is a parameter especially useful in the overweight and obese population to determine the best amount of exercise intensity for weight loss and increasing physical fitness. The aim of study is to propose a new procedure to automatically identify AerT using the analysis of recurrences (RQA) relying only on Heart rate time series, acquired from a cohort of young athletes during a sub-maximal incremental exercise test (Cardiopulmonary Exercise Test, CPET) on a cycle ergometer. We found that the minima of determinism, an RQA feature calculated from the Recurrence Quantification by Epochs (RQE) approach, identify the time points where generic metabolic transitions occur. Among these transitions, a criterion based on the maximum convexity of the determinism minima allows to detect the first metabolic threshold. The ordinary least products regression analysis shows that values of the oxygen consumption VO2 , heart rate (HR), and Workload correspondent to the AerT estimated by RQA are strongly correlated with the one estimated by CPET (r > 0.64). Mean percentage differences are <2% for both HR and VO2 and <11% for Workload. The Technical Error for HR at AerT is <8%; intraclass correlation coefficients values are moderate (≥0.66) for all variables at AerT. This system thus represents a useful method to detect AerT relying only on heart rate time series, and once validated for different activities, in future, can be easily implemented in applications acquiring data from portable heart rate monitors

Physical Education on the Beach: An Alternative Way to Improve Primary School Children’s Skill- and Health-Related Outcomes during the COVID-19 Pandemic

: The COVID-19 restrictions could preclude children from participating in physical education (PE) interventions. This study aimed to evaluate the efficacy of a PE intervention conducted on the beach on children's skill- and health-related outcomes, as a possible alternative PE intervention that could be also applied during the COVID-19 pandemic. The study involved 106 primary school children, randomly assigned to the traditional indoor (TI) intervention or to the experimental outdoor (EO) intervention. The intervention period lasted 4 months and consisted of two 1-h sessions per week. Intervention was conducted just before the beginning of the COVID-19 pandemic. Children's anthropometric parameters (height, weight, BMI, body fat percentage, and abdominal circumference), fitness parameter (VO2peak), health parameters (resting heart rate, and systolic and diastolic blood pressure), gross motor coordination, and physical activity level were assessed before and after intervention. Both groups significantly improved fitness and motor coordination but worsened some anthropometric parameters (weight, abdominal circumference) after the intervention period. The EO group showed a higher increase of gross motor coordination than the TI group. Results of this study demonstrated that children benefited from a well-structured PE intervention conducted in the natural environment of the beach improving physical fitness and gross motor coordination. Therefore, planning outdoor PE interventions could be an alternative and safe way to encourage and implement physical activity at school during the particular period of COVID-19 pandemic

Effects of sports experience on children's gross motor coordination level

Background: Gross motor coordination (GMC) development could be influenced by age, gender, weight status, geographical area, living setting, home environment, socio-economic status, sports practice. Purpose: To verify whether practicing sports and practicing different sports could influence children's GMC level. Methods: A total of 295 children aged 8-11 years were involved in the study and divided into 5 groups in relation to the sport they practiced: gymnastics group (n = 67; 51F, 16M), cycling group (n = 64; 15F, 49M), athletics group (n = 47; 22F, 25M), swimming group (n = 35; 20F, 15M), control group (n = 82; 42F, 40M). The four subtests of the Körperkoordinations Test für Kinder (KTK) assessed children's GMC level. The scores from each of the four subtests were summed into the KTK total raw score (RS) and then converted into a gender- and age-specific motor quotient (MQ). Results: Children practicing sports showed significantly higher RS and MQ score than children of control group (203.14 ± 38.55 vs. 163.63 ± 43.50 and 98.56 ± 15.79 vs. 83.01 ± 16.71, respectively; p < 0.001). Children practicing gymnastics had a significantly higher RS and MQ than children of cycling, swimming, and control groups (p < 0.05), children of control group had a significantly lower RS and MQ than children of all other groups (p < 0.05). Children practicing gymnastics performed better walking backwards subtest than all other children's groups (p < 0.001). Children of control group performed worse jumping sideways subtest than children of gymnastics, athletics and swimming groups (p < 0.01). Children practicing gymnastics performed better moving sideways subtest than children of athletics, cycling and control groups (p < 0.01); children of control group performed worse than children of all other groups (p < 0.01). Children of control group performed worse hopping for height subtest than children of gymnastics, athletics and cycling groups (p < 0.05); children practicing gymnastics performed better than children of swimming and control groups (p < 0.05). Conclusions: The performance model and therefore the specialized training that each sport discipline required, could justified the differences in children's GMC level among sports groups. Thus, coaches should plan individualized interventions and choose activity contents to support children's GMC development

Körperkoordinations test für Kinder: A short form is not fully satisfactory

Assessment of motor competence (MC) is crucial to finding deficiencies in children's motor development. Because of the need to ensure validity, reliability, and feasibility, the selection of contemporary testing batteries is a difficult task. Many papers report the validity of the KTK test in describing MC in school aged children. KTK consists of 4 four separate items: walking back, jumping sideways, moving sideways, and hopping for height. Some authors suggested the use of a short version of KTK that includes 3 items excluding one subtest: hopping for height. This study aimed to evaluate the effectiveness of short versions of Körperkoordinationstest für Kinder (KTK). A sample of 2,231 participants (boys: n=1,188; girls: n = 1,043; age range: 6–12 years) were recruited from Italian schools between January 2019 and February 2020 and they performed the complete version of KTK. Stepwise linear regression was performed on the dataset to evaluate the ideal number of variables to describe the KTK short form version. Data for both the sexes and all ages indicated that considering the item combinations of each short version, the highest R squares were obtained in those that included exactly the deleted subtest (ranging from 0.881–0.979). The adoption of a short form does not seem to provide a fully satisfactory condition for measuring MC in children 6–12 years

Interrelationship between age, gender, and weight status on motor coordination in Italian children and early adolescents aged 6-13 years old

Although numerous evidences reported a negative correlation between motor coordination (MC) and overweight/obesity in children and adolescents, the interrelationship between age, gender, and weight status is still debatable. Hence, the aim of this cross-sectional study was to examine the association between MC and weight status according to age and gender across childhood and early adolescence in a large sample of Italian elementary and middle school students. A number of 1961 Italian school students (1,026 boys, 935 girls) was stratified in three consecutive age groups (6-7, 8-10, and 11-13 years) and four weight status categories (underweight, normal weight, overweight, and obese) according to Cole's body mass index (BMI) cut-off points for children. MC performance was assessed measuring motor quotient (MQ) with the Körperkoordinationstest für Kinder (KTK). Results showed significantly lower MQ levels in children in overweight (OW) and with obesity (OB) in both sexes for all age groups than peers in normal weight (NW), except in 6-7-year-old boys. Girls in OW and with OB had similar MQ levels across all age groups, while younger boys in OW and with OB showed higher MQ levels than older ones (p < 0.05). The 6-7-year-old boys showed better MQ levels than girls peers in NW, OW, and with OB, while 8-10-year-old boys in underweight (UW), NW, and OW; and 11-13-year-old boys only in NW (p < 0.05). No interaction effect was found between age, gender, and weight status on MQ levels. These outcomes showed the negative impact of higher weight status on MC performance according to age and gender, pointing out the importance of planning targeted motor programs that consider these variables to improve MC performance

Oxygen uptake efficiency slope in healthy normal weight young males: an applicable framework for calculation and interpretation

Background The oxygen uptake efficiency slope (OUES) is considered a reliable indicator of cardiorespiratory fitness in young and clinical populations who cannot achieve maximal effort during a graded exercise test. However, OUES accuracy depends on the data points used for its calculation and it is still not clear if the submaximal OUES can accurately assess CRF in healthy young males. Objective We investigated the association between peak oxygen uptake and peak and submaximal OUES, and the agreement between submaximal OUES and peak OUES in male adolescents and young adults. Methods In this cross-sectional, observational study, fifty normal weight healthy participants (age 14–22 years, peak oxygen uptake 43.8 ± 7.3 mL·min−1·kg−1) performed a graded exercise test on a cycle ergometer and pulmonary gas exchange was assessed using breath-by-breath analysis. Peak oxygen uptake, and oxygen consumption at the aerobic and at the anaerobic threshold were determined as the 30-s average of the oxygen consumption values. Peak OUES (up to peak) and submaximal OUES (up to the aerobic and anaerobic thresholds) were calculated from the logarithmic relation between oxygen consumption and pulmonary ventilation. Results Very strong correlations were observed between peak oxygen uptake and peak OUES (r = 0.80–0.88) while fair-to-very strong correlations were observed between the peak oxygen uptake and the two submaximal OUES (r = 0.32–0.81). The level of agreement between peak OUES and OUES up to the anaerobic threshold (r = 0.89–0.93; Typical percentage error 6%; Intraclass correlation coefficient = 0.89–0.93) was greater than the one between the peak oxygen uptake with OUES up to the aerobic threshold (r = 0.39–0.56; Typical percentage error 15%; Intraclass correlation coefficient = 0.38–0.56). Conclusions . The peak OUES is a better indicator of aerobic fitness than the OUES up to the anaerobic threshold in healthy, young males. The OUES up to the anaerobic threshold is a valid alternative to peak OUES

POSTURAL CONTROL AFTER A PROLONGED TREADMILL RUN AT INDIVIDUAL VENTILATORY AND ANAEROBIC THRESHOLD

The objective of the study was to verify whether young males' balance was affected by 30min prolonged treadmill running (TR) at individual ventilatory (IVT) and anaerobic (IAT) thresholds in recovery time. The VO2max, IAT and IVT during an incremental TR were determined. Mean displacement amplitude (Acp) and velocity (Vcp) of center of pressure were recorded before (pre) and after (0min post; 5min post; and 10min post) prolonged TR at IAT and IVT, through posturographic trials performed with eyes open (EO) and closed (EC). Significant differences between IVT and IAT for Vcp, between EO and EC for Acp and Vcp, were observed. The IAT induced higher destabilizing effect when postural trials were performed with EC. The IVT intensity produced also a destabilizing effect on postural control immediately after exercise. An impairment of postural control after prolonged treadmill running exercise at IVT and IAT intensity was showed. However, destabilizing effect on postural control disappeared within 10min after IAT intensity and within 5min after IVT intensit

Effects of open (Racket) and closed (running) skill sports practice on children’s attentional performance.

Aims: The first aim of the study was to examine the attentional performance of children (8–13 years of age) who practiced two different sport disciplines: Open skill sport – racket and closed skill sport – running and also to investigate the acute effects of these two specific training sessions on children’s immediate and delayed attentional performance. The second aim of the present study was to verify gender differences in attentional performance. Eighteen children+ (8 girls and 10 boys; age = 10.6 ± 1.5 yrs; height = 144.3 ± 12.2 cm; weight = 44.2 ± 12.5 kg; BMI = 20.8 ± 2.7 kg/m2) engaged in a racket sports and eighteen children (9 girls and 9 boys; age = 9.9 ± 1.2 yrs; height = 142.4 ± 9.5 cm; weight = 40.0 ± 8.6 kg; BMI = 19.6 ± 2.4 kg/m2) engaged in running were enrolled. Methods: Children’s training and experience with these activities averaged 2.3 (± 1.0) years. Children’s attentional capacity was measured before, immediately after and 50 minutes after each specific training session by the d2 test of attention. This paper -and -pencil letter cancellation test evaluated concentration and sustained attention under stress induced by a fixed executing time. A 2 (Sport: open vs closed skill) x 2 (Gender: boys vs girls) x 3 (Time: pre vs 0’ post vs 50’ post) repeated measures ANOVA for time was used to compare the effect of an open skill session and a closed skill session on the individual attentional variables. Results: Children of open skill sport showed higher attentional scores (higher processing speed - TN, higher concentration performance - CP and lower percentage of errors - E%; p < 0.01), improved CP from pre to 0’ post intervention (p = 0.01) and maintained this improved performance at 50’ post intervention (50’ post vs pre; p < 0.01), and decreased E% from pre to 0’ post intervention (p = 0.01) and maintained this improvement at 50’ post intervention (50’ post vs pre; p < 0.001). Children of closed skill sport significantly decreased their CP from pre to 50’ post intervention (50’ post vs pre; p = 0.001 and 50’ post vs 0’ post; p < 0.0001) and worsened their E% across the time (50’ post vs pre; p = 0.001 and 50’ post vs 0’ post; p < 0.0001). Boys showed significantly higher TN values than girls only in closed skill sport (p = 0.023). Finally, all girls of both open and closed skill sports significantly improved their CP from pre to 0’ post intervention (p = 0.04). Conclusion: Results of the study showed that open skill sport practice and training session positively affects children’s attentional performance

Benefici dell’Allenamento Sportivo Inclusivo sulla Fitness e sulla Salute di Atleti con e senza Disabilità Intellettiva

This study aimed to assess the variation of fitness level in athletes with ID before and after an 8-month Inclusive (IS) and Not Inclusive Sport (NIS) training. Thirty-eight athletes with ID and 14 athletes without ID belonged to IS group, 38 athletes with ID to the NIS group and 23 participants with ID to the Control group (not attending to any sport). Before and after the intervention period, all participants performed fitness tests assessing body composition, flexibility (SR), explosive leg power (SLJ), balance ability (FT), lower and upper-body muscular strength and endurance (SUP and PUP), arm muscular strength (HG), cardiovascular endurance (ST), motor coordination (TUGT), lower-body speed (10x5 SR), and upper-body speed (PT). Results showed that all athletes with ID significantly improved their body composition, ST, FT and PUP after the training period, and athletes of the NIS training (with and without ID) obtained significantly better scores in all fitness tests after the intervention (p < 0.05), showing how inclusive training may bring more effective results on all athletes