Who changed and who maintained their urban bike-sharing mobility after the COVID-19 outbreak? A within-subjects study.

The COVID-19 pandemic has remarkably impacted urban mobility. All non-essential movements were restricted in Valencia (Spain) to contain the virus. Thus, the transport usage patterns of Valencia's bike-sharing system (BSS) users changed during this emergency situation. The primary objective of this study was to analyse the behaviour patterns of BSS users in Valencia before and after the COVID-19 outbreak, specifically those who maintained or changed their transport routines. A within-subjects comparison design was developed using a group of BSS users before and after the onset of the pandemic. Data mining techniques were used on a sample of 4355 regular users and 25 variables were calculated to classify users by self-organising maps analysis. The results show a significant reduction (40 %) in BSS movements after the outbreak during the entire post-outbreak year. There was some recovery during the rest of 2020; however, this has yet to reach the pre-pandemic levels, with variations observed based on the activities performed in different areas of the city. Of the users, 63 % changed their BSS use patterns after the onset of the pandemic (LEAVE group), while 37 % maintained their patterns (REMAIN group). The user profile of the REMAIN group was characterised by a general reduction of approximately 35 % of journeys during 2020, with a slight increase in morning movements compared to those made in the evening. These users also presented an equivalent number of cycling days to those of the previous year, reduced the number of connections and increased the network's density and the travelling speed. These results can be useful in estimating the percentage of people who do not vary their usual behaviour during emergencies. Finally, several policy implications are outlined based on the findings.

Encouraging People with Spinal Cord Injury to Take Part in Physical Activity in the COVID-19 Epidemic through the mHealth ParaSportAPP.

BACKGROUND: Although mHealth tools have great potential for health interventions, few experimental studies report on their use by people with spinal cord injuries in physical activity. OBJECTIVE: The main objective of this study was to analyze the effect of the ParaSportAPP on different physical and psychological variables in people with paraplegia. METHODS: Fourteen of these subjects made up the final sample. All the participants performed two pre-tests (control period) and a post-test with 8 months between the evaluations (COVID-19 broke out between pre-test 2 and the post-test). The ParaSportAPP was installed on their smartphones when they performed pre-test 2. The same tests were performed in the same order in all the evaluations: (i) the questionnaires PASIPD, HADS, RS-25; SCIM III and AQoL-8D, (ii) respiratory muscle strength, (iii) spirometry and (iv) cardiopulmonary exercise test. RESULTS: The results showed no differences in any of the variables studied between the measurement times. CONCLUSIONS: Although none of the variables experienced improvements, the ParaSportAPP mobile application was able to lessen the impact of the pandemic on the variables studied.

Impact of COVID-19 on the self-reported physical activity of people with complete thoracic spinal cord injury full-time manual wheelchair users.

CONTEXT: The emergence of COVID-19 caused a new public health crisis, leading to major changes in daily life routines, often including physical activity (PA) levels. The main goal of this study was to analyze the differences in self-reported physical activity of people with complete spinal cord injuries between the time prior to the COVID-19 lockdown and the lockdown period itself. METHODS: A sample of 20 participants with complete thoracic spinal cord injuries completed the Physical Activity Scale for Individuals with Physical Disabilities before and during the COVID-19 lockdown. RESULTS: The results showed differences between the pre-lockdown and lockdown measurements in total self-reported PA (z=-3.92; P<0.001; d=1.28), recreational PA (z=-3.92; P<0.001; d=1.18) and occupational PA (z=-2.03; P=0.042; d=0.55). Nevertheless, no differences were found in housework PA between the two time periods. Furthermore, the results showed differences in total minutes (z=-3.92; P<0.001; d=1.75), minutes spent on recreational activities (z=-3.82; P<0.001; d=1.56) and minutes spent on occupational activities (z=-2.032; P=0.042; d=0.55) of moderate/vigorous intensity. CONCLUSIONS: Individuals with thoracic spinal cord injuries who were full-time manual wheelchair users displayed lower levels of PA during the pandemic than in the pre-pandemic period. The results suggest that the prohibition and restrictions on carrying out recreational and/or occupational activities are the main reasons for this inactivity. Physical activity promotion strategies should be implemented within this population to lessen the effects of this physical inactivity stemming from the COVID-19 pandemic.

Physical Activity and Exercise: Text Mining Analysis.

It is currently difficult to have a global state of the art vision of certain scientific topics. In the field of physical activity (PA) and exercise, this is due to information overload. The present study aims to provide a solution by analysing a large mass of scientific articles using text mining (TM). The purpose was to analyse what is being investigated in the PA health field on young people from primary, secondary and higher education. Titles and abstracts published in the Web of Science (WOS) database were analysed using TM on 24 November 2020, and after removing duplicates, 85,368 remained. The results show 9960 (unique) words and the most frequently used bi-grams and tri-grams. A co-occurrence network was also generated. 'Health' was the first term of importance and the most repeated bi-grams and tri-grams were 'body_mass' and 'body_mass_index'. The analyses of the 20 topics identified focused on health-related terms, the social sphere, sports performance and research processes. It also found that the terms health and exercise have become more important in recent years.

The tightening parameters of the vibratory devices modify their disturbing postural effects.

The purpose was to specify the impact of two different forces exerted by vibratory devices on the Achilles tendon on postural balance. The postural balance of 13 participants was evaluated on a force platform in two 40 s bipedal stance conditions with closed eyes. Tendon vibrations (80 Hz) were triggered 10 s after the beginning of the postural evaluation and applied during 20 s. Two levels of the force exerted by the vibrators were calibrated using load cells to control the tightening parameters of the vibrators: a strong tightening (ST) condition at 45 N and a light tightening (LT) condition at 5 N. The soleus electromyographic (EMG) activity and the spatio-temporal parameters of displacement of the centre of foot pressure (COP) were analysed. To analyse the effects of the introduction, the adaptation and the end of the stimulation, non-parametric tests were used. The results indicated that the soleus EMG activity increased only in the ST condition. However, during the vibration the anteroposterior COP position was significantly more in a backward position in the LT condition. At the end of the vibration, COP parameters increased more in the LT condition than the ST condition. This study demonstrated that the effects of the vibration depended on the force exerted by the devices on the tendons. The ST increased the vibration effects on EMG activity through greater stimulating effects compared to the LT. However, the ST could also increase the ankle joint stiffness and/or somaesthetic sensory information, which attenuated the COP backward shift.

The Impact of COVID-19 on Sport in Twitter: A Quantitative and Qualitative Content Analysis.

The spread of the SARS-CoV-2 virus has transformed many aspects of people's daily life, including sports. Social networks have been flooded on these issues. The present study aims to analyze the tweets produced relating to sports and COVID-19. From the end of January to the beginning of May 2020, over 4,000,000 tweets on this subject were downloaded through the Twitter search API. Once the duplicates, replicas, and retweets were removed, 119,253 original tweets were analyzed. A quantitative-qualitative content analysis was used to study the selected tweets. Posts dynamics regarding sport and exercise evolved according to the COVID-19 pandemic and subsequent lockdown, shifting from considering sport as a healthy bastion to an activity exposed to disease like any other. Most media professional sporting events received great attention on Twitter, while grassroots and women's sport were relegated to a residual role. The analysis of the 30 topics identified focused on the social, sporting, economic and health impact of the pandemic on the sport. Sporting cancellations, leisure time and socialization disruptions, club bankruptcies, sports training and athletes' uncertain career development were the main concerns. Although general health measures appeared in the tweets analyzed, those addressed to sports practice were relatively scarce. Finally, this study shows the importance of Twitter as a means of conveying social attitudes towards sports and COVID-19 and its potential to generate alternative responses in future stages of the pandemic.

Validation of Using Smartphone Built-In Accelerometers to Estimate the Active Energy Expenditures of Full-Time Manual Wheelchair Users with Spinal Cord Injury.

This study aimed to investigate the validity of using built-in smartphone accelerometers to estimate the active energy expenditures of full-time manual wheelchair users with spinal cord injury (SCI). Twenty participants with complete SCI completed 10 5-min daily activities that involved the upper limbs, during which their oxygen consumption and upper limb activity were registered using a portable gas analyzer and a smartphone (placed on the non-dominant arm), respectively. Time series of 1-min averaged oxygen consumption and 55 accelerometer variables (13 variables for each of the four axes and three additional variables for the correlations between axes) were used to estimate three multiple linear models, using a 10-fold cross-validation method. The results showed that models that included either all variables and models or that only included the linear variables showed comparable performance, with a correlation of 0.72. Slightly worse general performance was demonstrated by the model that only included non-linear variables, although it proved to be more accurate at estimating the energy expenditures (EE) during specific tasks. These results suggest that smartphones could be a promising low-cost alternative to laboratory-grade accelerometers to estimate the energy expenditure of wheelchair users with spinal cord injury during daily activities.

Screen time among Spanish university students with disabilities: a self-organizing maps analysis.

BACKGROUND: Screen time can play a significant role in the health and quality of life of people with disabilities. However, there is a lack of studies on this issue among people with disabilities, and even fewer in the university setting. Thus, the aim of our study was to explore the relationships between screen time, disability grade, body mass index (BMI), physical activity and sociodemographic variables (gender and socioeconomic status) in university students with different disabilities. METHODS: A cross-sectional study was conducted on a sample of 1091 students with disabilities from 55 Spanish universities. Instruments used for data gathering were the Adolescent Sedentary Activity Questionnaire (ASAQ) and the International Physical Activity Questionnaire-Short Form (IPAQ-SF). A Self-Organizing Maps (SOM) analysis was carried out to explore the relationships between the variables under study. RESULTS: Participants reported high values in overall screen time (5.45 h per day/week), with computers being the media most used (2.45 h per day/week). The SOM analysis showed slightly higher screen time values in women than men. People with a high disability grade spent less screen time than those with lower disability grade. Contradictory results exist when a group of men with the highest BMI had the highest screen time and the lowest physical activity (PA) while women with low BMI show the highest screen time and PA. CONCLUSIONS: Gender and disability grade played a moderating role in screen time among people with disabilities while BMI and PA do not play such a role.

Assessment of haemophilic arthropathy through balance analysis: a promising tool.

The purpose of this study was to develop a tool able to distinguish between subjects who have haemophilic arthropathy in lower limbs and those who do not by analyzing the centre of pressure displacement. The second objective was to assess the possible different responses of haemophiliacs and healthy subjects by creating a classifier that could distinguish between both groups. Fifty-four haemophilic patients (28 with and 26 without arthropathy) and 23 healthy subjects took part voluntarily in the study. A force plate was used to measure postural stability. A total of 276 centre of pressure displacement parameters were calculated under different conditions: unipedal/bipedal balance with eyes open/closed. These parameters were used to design a Quadratic Discriminant Analysis classifier. The arthropathy versus non-arthropathy classifier had an overall accuracy of 97.5% when only 10 features were used in its design. Similarly, the haemophiliac versus non-haemophiliac classifier had an overall accuracy of 97.2% when only 7 features were used. In conclusion, an objective haemophilic arthropathy in lower limbs evaluation system was developed by analyzing centre of pressure displacement signals. The haemophiliac vs. non-haemophiliac classifier designed was also able to corroborate the existing differences in postural control between haemophilic patients (with and without arthropathy) and healthy subjects.

An author keyword analysis for mapping Sport Sciences.

Scientific production has increased exponentially in recent years. It is necessary to find methodological strategies for understanding holistic or macro views of the major research trends developed in specific fields. Data mining is a useful technique to address this task. In particular, our study presents a global analysis of the information generated during last decades in the Sport Sciences Category (SSC) included in the Web of Science database. An analysis of the frequency of appearance and the dynamics of the Author Keywords (AKs) has been made for the last thirty years. Likewise, the network of co-occurrences established between words and the survival time of new words that have appeared since 2001 has also been analysed. One of the main findings of our research is the identification of six large thematic clusters in the SSC. There are also two major terms that coexist ('REHABILITATION' and 'EXERCISE') and show a high frequency of appearance, as well as a key behaviour in the calculated co-occurrence networks. Another significant finding is that AKs are mostly accepted in the SSC since there has been high percentage of new terms during 2001-2006, although they have a low survival period. These results support a multidisciplinary perspective within the Sport Sciences field of study and a colonization of the field by rehabilitation according to our AK analysis.

Effects of Rapid Weight Loss on Balance and Reaction Time in Elite Judo Athletes.

Balance, reaction time, and strength are key factors affecting judo performance. Although ample research has been done examining potential strength changes caused by weight loss prior to competition, changes in balance and reaction time have been overlooked. PURPOSE: To examine the effects of rapid and progressive weight loss (RWL and PWL) on balance, reaction time, and strength in a group of elite judo athletes. METHODS: A total of 38 female and male judo athletes (age = 20.6 [2.6] y) completed balance, reaction-time, and strength assessments 1 wk prior to an official weigh-in (pretest) and immediately after the weigh-in (posttest). The athletes were divided into 3 groups, 1 control group who maintained regular training and eating habits, 1 experimental group who engaged in PWL (<3% reductions in body mass), and a second experimental group who used RWL techniques (>3% reductions in body mass). RESULTS: The RWL group showed significant decreases (P < .05) in balance performance (ellipse area: 4.83 [0.87] vs 6.31 [1.39] mm2 with eyes closed; mean mediolateral velocity: 2.07 [0.2] vs 2.52 [0.45] mm·s-1 with eyes closed; and mean anteroposterior velocity: 2.25 [0.20] vs 2.51 [0.32] mm·s-1 with eyes open and 2.44 [0.26] vs 3.06 [0.56] mm·s-1 with eyes closed) and reaction time (0.38 [0.04] vs 0.42 [0.06] s) with no changes in strength from pretesting to posttesting. The athletes in the PWL and control groups maintained performance in all variables. CONCLUSION: These findings demonstrate negative effects on perceptual motor-skill performance in judo athletes engaging in RWL strategies prior to competition.

Relationship between body composition and vertical ground reaction forces in obese children when walking.

BACKGROUND: Obesity is now a serious worldwide challenge, especially in children. This condition can cause a number of different health problems, including musculoskeletal disorders, some of which are due to mechanical stress caused by excess body weight. The aim of this study was to determine the association between body composition and the vertical ground reaction force produced during walking in obese children. METHODS: Sixteen children participated in the study, six females and ten males [11.5 (1.2) years old, 69.8 (15.5) kg, 1.56 (0.09) m, and 28.36 (3.74) kg/m2 of body mass index (BMI)]. Total weight, lean mass and fat mass were measured by dual-energy X-ray absorptiometry and vertical forces while walking were obtained by a force platform. The vertical force variables analysed were impact and propulsive forces, and the rate of development of both. Multiple regression models for each vertical force parameter were calculated using the body composition variables as input. FINDINGS: The impact force regression model was found to be positively related to the weight of obese children and negatively related to lean mass. The regression model showed lean mass was positively related to the propulsive rate. Finally, regression models for impact and propulsive force showed a direct relationship with body weight. INTERPRETATION: Impact force is positively related to the weight of obese children, but lean mass helps to reduce the impact force in this population. Exercise could help obese persons to reduce their total body weight and increase their lean mass, thus reducing impact forces during sports and other activities.

Differences in intermittent postural control between normal-weight and obese children.

AIM: The main objective of this study was to determine differences in postural control between obese and non-obese children. METHODS: The study design was cross-sectional, prospective, between-subjects. Postural control variables were obtained from a group of obese children and a normal-weight control group under two different postural conditions: bipedal standing position with eyes open and bipedal standing with eyes closed. Variables were obtained for each balance condition using time domain and sway-density plot analysis of the center of pressure signals acquired by means of a force plate. RESULTS: Pairwise comparisons revealed significant differences between obese and normal-weight children in mean velocity in antero-posterior and medio-lateral directions, ellipse area and mean distance with both eyes open and eyes closed. Normal-weight subjects obtained lower values in all these variables than obese subjects. Furthermore, there were differences between both groups in mean peaks with eyes open and in mean time with eyes closed. CONCLUSION: Alterations were detected in the intermittent postural control in obese children. According to the results obtained, active anticipatory control produces higher center of pressure displacement responses in obese children and the periods during which balance is maintained by passive control and reflex mechanisms are of shorter duration.

The Work Endurance Recovery Method for Quantifying Training Loads in Judo.

PURPOSE: To adapt the work endurance recovery (WER) method based on randori maximal time to exhaustion (RMTE) for combat situations in judo. METHODS: Eleven international-standard judo athletes (7 men and 4 women; mean age 20.73 ± 2.49 y, height 1.72 ± 0.11 m, body mass 67.36 ± 10.67 kg) were recruited to take part in the study. All participants performed a maximal incremental test (MIT), a Wingate test (WIN), a Special Judo Fitness Test (SJFT), and 2 RMTE tests. They then took part in a session at an international training camp in Barcelona, Spain, in which 4 methods of load quantification were implemented: the WER method, the Stagno method, the Lucia method, and the session rating of perceived exertion (RPEsession). RESULTS: RMTE demonstrated a very high test-retest reliability (intraclass correlation coefficient = .91), and correlations of the performance tests ranged from moderate to high: RMTE and MIT (r = .66), RMTE and WIN variables (r = .38-.53), RMTE and SJFT variables (r = .74-.77). The correlation between the WER method, which considers time to exhaustion, and the other systems for quantifying training load was high: WER and RPEsession (r = .87), WER and Stagno (r = .77), WER and Lucia (r = .73). A comparative repeated-measures analysis of variance of the normalized values of the quantification did not yield statistically significant differences. CONCLUSIONS: The WER method using RMTE is highly adaptable to quantify randori judo sessions and enables one to plan a priori individualized training loads.

POSTURAL CONTROL MECHANISMS IN HEALTHY ADULTS IN SITTING AND STANDING POSITIONS.

This study explored differences in the center of pressure in healthy people in a sitting and standing position and with eyes open and closed. With this purpose, 32 healthy participants (16 men, 16 women; M age=25.2 yr., SD=10.0, range=18-55) were measured with an extensiometric force plate. Using a two-way repeated-measures multivariate analysis of variance (MANOVA), the root mean square, velocity, range, and sway, in both visual conditions, had higher values in the standing task than in the sitting task. In the frequency domain, the low-frequency band had higher values during the standing task. For control mechanism variables, mean distance and time were greater when standing while mean peaks were greater when sitting. Thus, stability is worse in the standing position and more neuromuscular activity is required to maintain balance.

Physical activity, physical fitness and academic achievement in adolescents: a self-organizing maps approach.

The relationship among physical activity, physical fitness and academic achievement in adolescents has been widely studied; however, controversy concerning this topic persists. The methods used thus far to analyse the relationship between these variables have included mostly traditional lineal analysis according to the available literature. The aim of this study was to perform a visual analysis of this relationship with self-organizing maps and to monitor the subject's evolution during the 4 years of secondary school. Four hundred and forty-four students participated in the study. The physical activity and physical fitness of the participants were measured, and the participants' grade point averages were obtained from the five participant institutions. Four main clusters representing two primary student profiles with few differences between boys and girls were observed. The clustering demonstrated that students with higher energy expenditure and better physical fitness exhibited lower body mass index (BMI) and higher academic performance, whereas those adolescents with lower energy expenditure exhibited worse physical fitness, higher BMI and lower academic performance. With respect to the evolution of the students during the 4 years, ∼25% of the students originally clustered in a negative profile moved to a positive profile, and there was no movement in the opposite direction.

Use of heart rate variability in monitoring stress and recovery in judo athletes.

The main objective of this study was to examine the effect of different judo training loads on heart rate variability (HRV) measurements, to determine if they can be used as valid indicators in monitoring stress and recovery in judo athletes. Fourteen male national-standard judo athletes were randomly divided into 2 groups, and each group followed a different type of training, namely, a high training load (HTL) and a moderate training load program (MTL). Data collection included HRV measurements, a Recovery Stress Questionnaire for athletes (RESTQ-SPORT), and strength measurements, 4 weeks before and after the training program. The HTL group had lower square root of the mean squared difference of successive RR intervals, very low frequency, high frequency, short-term variability, short-range scaling exponents, general recovery, sport-specific recovery, general stress, maximum strength, maximum power, and higher low/high frequency ratio at posttest compared with pretest (p ≤ 0.05). The HTL group showed lower short-range and long-range scaling exponents, general recovery, sport-specific recovery, and higher general stress than the MTL group in posttest measurements (p ≤ 0.05). In conclusion, judo athletes enrolled in an HTL program showed an imbalance of the autonomic nervous system with decreased vagal modulation, together with a decrease in strength parameters, higher markers for stress, and a lower perception of recovery.

Relation between physical activity and academic performance in 3rd-year secondary education students.

The main aim of this study was to analyze the relationship between the amount of physical activity and academic performance in 3rd-year secondary education students. The sample was taken from three secondary schools in the area of Barcelona. 284 students (158 girls, 126 boys) with an average age of 14.7 yr. participated. The International Physical Activity Questionnaire was used by students to self-report their amount of physical activity. Students' academic records were obtained for comparisons. Results showed that there was a linear relationship between academic performance and physical activity; nevertheless, there was a trend to stronger correlation when modeling the relationship between these variables with a quadratic equation. Further research should focus on whether academic performance and physical activity might be better explained with a second-order equation.