The population of the world is aging. In Sweden alone, almost 20% of the population is 65 years or older. As people get older, problems with sleep disturbances and sleep quality tends to increase, as do the risks of falling injuries. In this thesis, methods for calculating sleep quality and if a person is about to leave a bed were devised. A bed sensor, measuring ballistocardiographical signals, was used to measure activity in bed and vital signs of the occupant. The Cole-Kripke algorithm, used to calculate sleep quality based on activity from a wrist worn sensor, was adapted to the bed sensor system and compared to results from the ActiGraph wGT3X-BT activity monitor, which is frequently used in research. The bed sensor systems sleep quality estimations showed strong correlation with the ActiGraph, with a Pearson correlation coefficient of 0.946. Two approaches were made to estimate if a subject was about to leave the bed, one by training a neural network on labeled night data, and one using a linear equation with each term consisting of activity data, optimized by linear regression. The neural network approach suffered from limited data, but the linear method showed more promise, with accuracy, specificity and sensitivity all over 70%.

No description available.

Studies with diverse populations including Caucasians, African-Americans, Asians, and Latinos have contributed important information about factors that may contribute to childhood obesity. However, the studies on Latino children have not examined how specific child and parent factors may be related to physical activity (PA) or sedentary behaviors (SB). Research investigations into these correlates or possible determinants of PA and SB in Latino children have only included children from Mexican American backgrounds. This dissertation consists of two studies designed to address the gaps in knowledge about these factors and their interaction with PA and SB in a specific group of Latino children. Data were obtained by direct evaluation of 75 children and their parents living on the Island of Puerto Rico. Objective measures, via accelerometry, were used to asses PA and SB, and questionnaires were used to obtain parental perceptions and beliefs about PA and SB. Child’s body composition was measured and used as a fitness component, along with a motor proficiency battery. Study 1 examined the relation between children’s fitness levels and level of motor skills, parental beliefs and perceptions of health status and children’s PA and SB. Results showed that time spent in SB and moderate to vigorous intensity PA (MVPA) was associated with parents’ intentions of reducing TV time and their perception of their child’s body weight. Study 2 undertook a more specific analysis of the mechanism(s) of these associations, specifically attempting to understand the possible moderation effect of certain constructs on the association between predictors of PA and SB. Results indicated that the strength of age as a predictor of MVPA and SB levels of Latino children may be moderated by the parent’s perception of influence, which in itself may be influenced by the parent’s level of education. Parental perceptions and intentions are modifiable factors, which suggests that working with the family is an important area to explore in future interventions to reduce obesity risk in this population.

The purpose of this study was to validate heart rate recording (Polar Vantage XL), and accelerometry (Tritrac-R3D) against a direct observational technique (BEACHES) in the assessment of physical activity in 49 healthy male and female pre-schoolers (3.0 to 5.9 yrs). Activity was assessed in a controlled laboratory environment and in 2 field trials during spontaneous uncontrolled activity. During the laboratory session, subjects wore a heart rate monitor and an accelerometer while performing a choreographed routine of activities. The actual level was coded concurrently on the BEACHES scale by a trained observer. The three measures were significantly correlated during the laboratory (r = 0.76-0.85) and field (r = 0.50-0.85) conditions. There was no difference in mean scores for activity level of the group between two different days of field observation, however, there was considerable intra-subject variability as reflected by the low to moderate rank order correlations for all techniques. It was found that a measurement interval of greater than 5 min would likely increase the correlations. These findings suggest that the three measures of PA provide similar information about the level of PA in both a controlled and the free play environment, and pre-school children as a group generally maintain a similar level of activity from day to day. / Thesis / Master of Science (MS)

The accurate measurement of total energy expenditure is a cornerstone of metabolic research. However, there is a lack of measurement methods that are valid, objective, inexpensive, and easy to use. Accelerometry, along with validated prediction equations for resting energy requirements, may provide an opportunity to fill this void. Twenty weight stable adults (12 female, 8 male) who recently participated in a controlled feeding study comprised the study sample. Total energy requirements were assessed from the controlled feeding period in which weight stability was achieved using the intake-balance method. Resting energy expenditure was assessed using the Mifflin-St. Jeor equation. Participants wore accelerometers to objectively assess habitual physical activity. The accelerometer data obtained along with subjects' demographic and biometric data were used to predict non-resting energy expenditure (NREE) using step-wise linear regression in JMP. Bland-Altman plots and Spearman's Rho correlations were used to determine the validity of the total energy requirements obtained from the sum of the predicted non-resting energy expenditure. Estimated resting energy expenditure was compared with the total energy requirements assessed using the intake-balance method from the controlled feeding period. The resulting prediction equation is as follows: 480.93 – 180.69(sex) + 0.21(Accelerometer kcals) + 617.98(BF%) = AEE. The sex was coded as 1 for females and 0 for males. This prediction model has a coefficient of determination of 0.74 (0.70 adjusted). On average, the model overestimates AEE by 76 kcals. This new model could be the key to accurately, inexpensively and objectively measuring total energy requirements. / Master of Science / Accurate measurement of the total amount of energy (i.e. calories) utilized by the body throughout the day, also known as total energy expenditure, is a vital component of metabolic research. However, there is a lack of measurement methods that are valid, objective, inexpensive, and easy to use. Accelerometers combined with equations designed to predict total energy expenditure may be able to fill this gap. Accelerometers are devices worn on the body that measure accelerative forces from physical activity. Twenty weight stable adults (12 female, 8 male), who recently participated in a study in which all dietary intake and exercise were closely monitored (controlled feeding study), comprised the study sample. The amount of energy needed to maintain weight (total energy requirements) was assessed from the controlled feeding period in which weight stability was achieved. Resting energy expenditure, the energy burned while the body is at rest, was assessed using an equation often used to estimate energy expenditure, the Mifflin-St. Jeor equation. Participants wore accelerometers to objectively assess habitual physical activity. The accelerometer data obtained along with subjects’ demographic (age, sex) and biometric (height, weight, BMI, etc.) data were used to predict non-resting energy expenditure (resting energy expenditure subtracted from total energy expenditure). Multiple statistical tests were used to determine the validity of the total energy requirements obtained from the sum of the predicted non-resting energy expenditure (NREE) and resting energy expenditure. Estimated resting energy expenditure was compared with the total energy requirements assessed using the intake-balance method from the controlled feeding period. The resulting prediction equation is as follows: 480.93 – 180.69(sex) + 0.21(Accelerometer kcals) + 617.98(BF%) = NREE. The sex was coded as 1 for females and 0 for males. This prediction model has a coefficient of determination of 0.74 (0.70 adjusted), which means 70% of the variation in non-resting energy expenditure was explained by changes in the variables in the equation. On average, the model overestimates NREE by 76 Calories per day. This new model could be the key to accurately, inexpensively and objectively measuring total energy requirements.

Coaches are constantly seeking more ecologically valid and reliable data to improve professional sporting performance. Using unobtrusive, valid and reliable mobile physiological monitoring devices may assist in achieving this aim. For example, there is limited information regarding professional fast bowlers in cricket and understanding this role during competitive in-match scenarios rather than in simulated bowling events could enhance coaching and physical conditioning practices. The BioharnessTM is a mobile monitoring device and assesses 5 variables (Heart rate [HR], Breathing frequency [BF], Accelerometry [ACC], Skin temperature [ST] and Posture [P]) simultaneously. Therefore, the aims of this research were to assess the effectiveness of the BioharnessTM mobile monitoring device during professional sporting performance using fast bowlers in cricket and this was to be achieved in five research studies. Study 1 presented the physiological profile of professional cricketers reporting fitness data with other comparable professional athletes, with a specific interest in fast bowlers who were to be the focus of this work. The 2nd and 3rd study assessed the reliability and validity of the BioharnessTM through controlled laboratory based assessment. For validity, strong relationships (r = .89 to .99, P < .01) were reported for HR, BF, ACC and P. Limits of Agreement reported HR (-3 ± 32 beat.min-1), BF (-3.5 ± 43.7 br.min-1) and P (0.2 ± 2.6o). ST established moderate relationships (-0.61 ± 1.98 oC; r =.76, P <.01). Reliability between subject data reported low Coefficient of Variation (CV) and strong correlations for ACC and P (CV < 7.6%; r = .99, P <.01). HR and BF (CV ~ 19.4%; r ~.70, P <.01) and ST (CV 3.7%; r = .61, P < .01), present more variable data. Intra and inter device data presented strong relationships (r > .89, P < .01, CV < 10.1%) for HR, ACC, P and ST. BF produced weaker data (r < .72, CV < 17.4%). Study 4 assessed reliability and validity of the BioharnessTM in a field based environment using an intermittent protocol. Precision of measurement reported good relationships (r = .61 to .67, P < .01) and large Limits of Agreement for HR (> 79.2 beat.min-1) and BF (> 54.7 br.min-1). ACC presented excellent precision (r = .94, P < .01). Results for HR (r = ~ .91, P < .01: CV <7.6%) and ACC (r > .97, P < .01; CV < 14.7%) suggested these variables are reliable in the field environment. BF presented more variable data (r = .46 - .61, P < .01; CV < 23.7%). In all studies, as velocity of movement increased (> 10 km.h-1) variables became more erroneous. HR and ACC were deemed as valid and reliable to be assessed during in-match sporting performance in study 5. This final study sought to utilise and assess the BioharnessTM device within professional cricket, assessing physiological responses of fast-medium bowlers within a competitive sporting environment, collected over three summer seasons. The BioharnessTM presented different physiological profiles for One Day (OD) and Multi Day (MD) cricket with higher mean HR (142 vs 137 beats.min-1, P < .05) and ACC (Peak acceleration (PkA) 227.6 vs 214.9 ct.episode-1, P < .01) values in the shorter match format. Differences in data for the varying match states of bowling (HR, 142 vs 137 beats.min-1, PkA 234.1 vs 226.6 ct.episode-1), between over (HR, 129 vs 120beats.min-1, PkA 136.4 vs 126.5 ct.episode-1) and fielding (115 vs 106 beats.min-1, PkA 1349.9 vs 356.1 ct.episode-1) were reported across OD and MD cricket. Therefore, this information suggests to the coach that the training regimes for fast bowlers should be specific for the different demands specific to the format of the game employed. Relationships between in-match BioharnessTM data and bowling performance were not clearly established due to the complexities of uncontrollable variables within competitive cricket. In conclusion, the BioharnessTM has demonstrated acceptable validity and reliability in the laboratory and the field setting for all variables (Heart rate, Breathing frequency, Accelerometry, Skin temperature and Posture) but with limitations for heart rate and breathing frequency at the more extreme levels of performance. Furthermore, taking these limitations into account it has successfully been utilised to assess performance and provide further insight into the physiological demands in the professional sport setting. Therefore, this work suggests that coaches and exercise scientists working together should seek to utilise new mobile monitoring technology to access unique insights in to sporting performance which may be unobtainable in the laboratory or a simulated field based event.

Physical inactivity among young people is a public health concern. Markers of physical inactivity, such as low cardio-respiratory fitness (CRF) and obesity are adversely related to higher order cognitive functions, which underpin goal directed behaviour (i.e. cognitive control) and are implicated in academic achievement. Regular aerobic exercise can benefit cognitive control in children. However, it remains unknown whether daily physical activity behaviour is associated with cognitive control. Investigating this is important as targeting increments in daily moderate-to-vigorous physical activity (MVPA) may initially be a more realistic policy goal than developing aerobic exercise interventions. Nominal number of studies assessed this relationship using objective monitoring of physical activity (accelerometry), and yielded mixed results. None of the studies into objectively measured physical activity and cognitive function in young people controlled for CRF, which is posited to mediate the relationship between regular aerobic exercise and cognitive control. Likewise, other important confounders such as intelligence, have yet to be addressed in the literature. Moreover, it is unknown whether this relationship varies with age, as extant studies looked solely at younger adolescents. For example, meta-analytical findings (Fedewa & Ahn, 2011) suggest that children can benefit more cognitively from CRF and chronic aerobic exercise than adolescents as greater effect sizes have been observed for younger compared to older youngsters. Alternatively, chronic aerobic exercise may be specifically needed for cognitive benefits to emerge. However, none of the aerobic exercise interventions included objective assessments of baseline physical activity and few studies assessed the effects of chronic aerobic exercise interventions on multiple indices of cognitive control. This thesis aimed to address the limitations of previous research and to investigate: 1) the associations between objectively measured daily MVPA and cognitive control in older adolescents (study 1), and 2) in preadolescent children (study 2), while controlling for CRF, general intellectual ability and a number of important confounders (e.g. adiposity, attention-deficit hyperactivity disorder); 3) the relationship between daily MVPA and academic achievement (study 2); 4) the effects of chronic aerobic exercise intervention on cognitive control in children, while controlling for objectively measured daily MVPA and time sedentary at baseline (study 3). Methods: Study 1. A sample of 667 adolescents (Mage = 15.4, SD = .17, 55.5% girls) from the Avon Longitudinal Study of Parents and Children was included in the analyses. MVPA was measured with ActiGraph, GT1M accelerometer. CRF was assessed with sub-maximal cycle ergometer test and expressed as weight adjusted predicted physical work capacity at the heart rate of 170 beats per minute (PWC-170). Attentional control was measured with Stop Signal task. Study 2. A sample of 81 children (Mage = 8.64 years, SD = .57, 45.7 % girls) was included in the analyses. MVPA was objectively measured using the ActiGraph, wGT3X+ accelerometer. CRF was measured using a maximal graded exercise test on a treadmill. Inhibitory control was assessed with a modified Eriksen flanker task, working memory with Operation Span Task; and academic achievement with Kaufman Test of Educational Achievement. Study 3. 32 children (Mage = 8.64, SD = .58, 56.2% girls) were randomised into a physical activity intervention (FITKids2) or a waitlist control group. Changes in VO2max were measured using a maximal graded treadmill exercise test and changes in MVPA were objectively monitored for 7 days using the ActiGraph, wGT3X+ accelerometer. Behavioural measures of inhibition (reaction time, and accuracy) and working memory (accuracy) were taken using computerised laboratory tasks (modified Eriksen flanker task and Operation Span Task). Results: Study 1. MVPA was not significantly related to cognitive processing speed or variability of cognitive performance in hierarchical linear regression models. In simple regression models, CRF was negatively related to mean RT on the simple go condition (R2 = 2.6%, F(1, 308) = 8.28, p = .004). Study 2. No significant associations were noted between MVPA and either inhibition, working memory, or academic achievement. In contrast, CRF explained 4.7% of variance in accuracy interference (ΔR2 = .047, p = .045; β = -.22, t(78) = 2.03, p = .045, F(2, 78) = 4.95, p = .009). Study 3. FITKids2 physical activity intervention had a positive effect on the speed of responding during incongruent condition of flanker task (F(1, 30) = 4.69, p = .038, ηp2 = .13). A significant increase in BMI percentile was observed in the control (Z = 2.17, p = .03) but not in the intervention group (p = .53). Discussion: Study 1. Our results suggest that aerobic fitness, but not MVPA, was associated with cognitive processing speed under less cognitively demanding task conditions. The results thus indicate a potential global effect of aerobic fitness on cognitive functions in adolescents but this may differ depending on the specific task characteristics. Study 2. The results of this study suggest that CRF but not objectively measured MVPA was associated with better interference control in preadolescent children. Given the intermittent nature of children s daily MVPA, it is possible that aerobic exercise, which increases CRF is needed for cognitive benefits to emerge. Study 3. FITKids2 after-school physical activity intervention had a positive effect on children s inhibitory control, namely this cognitive function, which is closely related to academic achievement and future job and health outcomes. Thus, the results of this study convey a positive public health message, where promoting child s engagement in aerobic exercise can engender benefits to their cognitive function. Conclusions: The findings from this thesis can inform development of physical activity interventions to benefit cognitive functions in young people and contribute to the evidence base to inform future health and educational policies.

Introdução - Com o crescimento da população idosa cresce a necessidade de incentivo a hábitos de vida saudáveis como a prática de atividade física (AF), bem como sua investigação, a fim de se prevenir a instalação de incapacidades. No entanto, são enormes as dificuldades de medida dessa atividade. O acelerômetro surge como uma das formas objetivas de avaliação da AF destacando-se por sua praticidade e capacidade de armazenamento de dados. Objetivo - Avaliar os níveis e intensidades de AF de idosos através da acelerometria e examinar as associações com fatores sócio-demográficos, de saúde e estilo de vida. Métodos - Estudo transversal com 568 idosos de 65 anos e mais da coorte de 2010 do estudo SABE. Os idosos usaram o acelerômetro ActiGraph (GT3X) por três dias posicionado na cintura. Resultados - A média geral de cpm foi de 341,29 (95 por cento IC 326,79 - 355,80). Não houve diferença entre homens e mulheres. A média de cpm diminuiu com a idade e para os idosos acometidos por todas as doenças, exceto hipertensão, doença pulmonar e doença articular. A mobilidade e CP reduzidas, um maior número de doenças e uma pior autopercepção de saúde estiveram associados de forma independente com menores cpm. Os homens divorciados/separados, os que viviam sozinho e os que possuíam de cino a oito anos de escolaridade apresentaram maiores cpm que as mulheres dessas categorias. A idade, o declínio cognitivo isolado ou associado à disfunção, a hipertensão, a doença cerebrovascular, a mobilidade e a CP, estiveram associados de forma independente à menores níveis de AF gerais e por sexo. Entre as mulheres o estado marital (solteira), a autopercepção de saúde (ruim/muito ruim) e os sintomas depressivos estiveram associados de forma independente a menores níveis de AF. Para os homens a suficiência de renda (não), presença de diabetes e o número de doenças (duas ou mais) estiveram associados de forma independente com menores níveis de AF. Após ajuste pelas demais variáveis, a idade se associou às cpm em ambos os sexos. Para o sexo feminino, a renda per capita e o tabagismo também demosntraram associação, e para os homens apenas o diabetes.Conclusão - Foram observados baixos níveis de AF entre os idosos do município de São Paulo, principalmente com o avançar da idade e na presença de doenças, que são muito comuns nessa população. Esse estudo reforça que a prática de AF deve ser incentivada e demonstra a necessidade de estudos longitudinais para se estabelecer a relação temporal entre esses fatores. / Introduction Togetherwith the growth of the elderly population, it also grows the necessity of encouraging a healthy lifestyle, with the practice of physical activity (PA), as well as its investigation, aiming at the prevention of potential disabilities. Nevertheless, the difficulties related to the measurement of such physical activity pose a considerable level of challenge. The accelerometer appears as an objective way of evaluating the PA, being distinguished by its practicality and ability to store data. Objective To evaluate the levels and intensities of PA in elderly people through accelerometry and examine the associations with socio-demographic, health and lifestyle factors.Methods Transversal study with 568 elderly citizens, aged 65 and above, who attended 2010 cohort of SABE Study. The elderly used the accelerometer ActiGraph (GT3X) for three days, placed in their waist. Results The general average cpm was 341,29 (95 per cent CI 326,79 355,80). There was no variation between men and women. The average cpmreduced according to the persons age and presence of diseases, except for hypertension, lung diseases and articular diseases. The reduced mobility and CP, a greater number of diseases and a worse auto health perceptionwere associated independently with lower cpm figures. The divorced/separated men, those who live on their own and those with five to eight years in the education system present higher cpm than women in those categories. The age, isolated cognitive decline or association with the disfunction, hypertension, cerebrovascular disease, mobility and calf circumference (CC), were associated independently with lower levels of general PA and per gender. Amongst women, the marital status (single), the auto health perception (bad/very bad) and the depression symptoms were associated independently to lower levels of PA. For men, the income sufficiency (no), presence of diabetes and number of diseases (two or more) were associated independently to lower levels of PA. Afteradjustment to other variables, the age was associated to the cpm in both genders. For the female, the income per capita and smoking also demonstrated association, and for men only the diabetes.Conclusion Lower levels of PA were observed in the elderly of the city of São Paulo, especially with age advancing and the presence of diseases, that are very common in this population. This study reinforces that the practice of PA should be encouraged and it demonstrates the necessity of longitudinal studies to establish the time relation with these factors.

Os objetivos desta pesquisa foram a) quantificar a prática de atividade física durante os dias de semana e finais de semana e avaliar o cumprimento das recomendações internacionais, b) mensurar indicadores de competência motora e c) verificar as relações entre essas variáveis em crianças de baixo nível socioeconômico. Participaram do estudo 234 crianças (44% meninas) entre 3 e 6 anos de idade (M=5,2; DP=0,78). Entre essas 234 crianças, 176 atingiram o critério de tempo mínimo de uso do acelerômetro, o qual foi utilizado para mensurar a prática de atividade física. A competência motora foi mensurada com a utilização do Test of Gross Motor Development (TGMD-2) e do Korperkoordination Test fur Kinder (KTK). Os resultados mostraram que os meninos despenderam mais tempo em atividade física total do que as meninas nos dias de semana (204,0 ± 44,0 xs 222,5 ± 41,8 minutos; p<0,01) e nos dias de final de semana (209,3 ± 49,3 xs 227,9 ± 65,0 minutos; p< 0,01). Em ambos os sexos, o tempo médio diário de atividade física total ficou acima das diretrizes internacionais de prática de atividade física para pré-escolares (> =180 minutos por dia). Em relação ao desempenho no TGMD-2, houve uma superioridade estatisticamente significante dos meninos principalmente nas habilidades de controle de objetos, com estabilização do desempenho, em ambos os sexos, por volta dos 5 anos de idade. No teste KTK, não houve diferença entre os sexos na pontuação total obtida. Quanto a associação entre as variáveis de atividade física e competência motora, apesar de estatisticamente significantes, os coeficientes de correlação foram reduzidos em ambos os sexos, oscilando entre r = 0,26 para a atividade física vigorosa dentro da escola e a pontuação total no controle de objetos nas meninas e r = 0,31 para a atividade física vigorosa fora da escola e a pontuação total no KTK para os meninos. Além disso, a análise do qui-quadrado demonstrou não existir associação entre o fato de atingir as recomendações internacionais de prática de atividade física total e o nível de competência motora. Conclui-se que os meninos apresentam maiores índices de prática de atividade física do que as meninas e possuem maior competência motora, especialmente nas habilidades de controle de objetos, porém, os valores reduzidos ou inexistentes de associação entre a prática de atividade física e a competência motora levantam um questionamento acerca da adequação das diretrizes internacionais de prática de atividade física na infância, indicando que a quantidade de atividade física talvez não seja um aspecto relevante para a aquisição de competência motora. Esses dados reforçam a necessidade de uma maior preocupação com aspectos qualitativos da atividade física / The objectives of this study were a) to quantify the practice of physical activity during the weekdays and weekends and assess compliance with international guidelines, b) to measure indicators of motor competence and c) to verify the relationships between these variables in children of low socioeconomic status. The study included 234 children (44% girls) between 3 and 6 years of age (M = 5.2, SD = 0.78). Among these 234 children, 176 reached the criteria of accelerometer use, which was used to measure physical activity. The motor competence was measured using the Test of Gross Motor Development (TGMD-2) and korperkoordination Test fur Kinder (KTK). The results showed that the boys spent more time in total physical activity than girls on weekdays (204.0 ± 44.0 xs 222.5 ± 41.8 minutes, p <0.01) and on weekends (209.3 ± 49.3 227.9 ± 65.0 minutes xs, p <0.01). In both genders, the daily average time of total physical activity was above the international uidelines for physical activity for preschoolers (>= 180 minutes per day). Regarding the performance on TGMD-2, there was a statistically significant superiority of boys mainly in object control skills, with stabilization of performance, in both genders, at about 5 years old. In the KTK, there was no difference between the genders in the total score. The association between physical activity and motor skills, although statistically significant, were reduced in both genders, ranging from r = 0.26 for vigorous physical activity within the school and the total score in object control skills in the girls and r = 0.31 for vigorous physical activity outside school and the total KTK score in the boys. In addition, chi-square analysis showed no association between attending the international guidelines of total physical activity and the level of motor competence. In conclusion, boys showed higher levels of total physical activity than girls and also showed greater motor competence, especially in object control skills; however, the low or non-significant values of association between physical activity and motor competence raise a question about the adequacy of international guidelines for physical activity in childhood, indicating that the amount of physical activity may not be a relevant aspect for the acquisition of motor competence. These data reinforce the need for a greater focus on qualitative aspects of physical activity

A castração de cães é um procedimento eletivo frequentemente realizado, e a sua prática tem sido associada com a queda nos níveis de atividade física e com ganho de peso. A grande maioria das pesquisas que envolvem a atividade física é realizada através de questionários que fornecem dados aceitáveis, porém subjetivos. Este trabalho teve por objetivo analisar de forma quantitativa, através do uso do acelerômetro, os níveis de atividade física e o ganho de peso de cadelas antes e após a castração. Foram utilizadas 21 cadelas e monitoradas através do acelerômetro em quatro momentos: antes, um mês, três meses e seis meses após a ovariossalpingohisterectomia. Os cães também foram avaliados quanto ao ambiente, peso, escore de condição corporal e porte. Não houve redução estatisticamente significativa dos níveis de atividade física após a castração. Ao fim dos seis meses de pós-operatório as atividades sedentária, leve a moderada e vigorosa permaneceram iguais àquelas anteriores à castração. O ambiente não influenciou o comportamento dos animais, pois apresentaram níveis de atividade muito semelhantes. Cadelas com sobrepeso tiveram maior variação de atividade em relação a cadelas de peso ideal e cadelas de porte grande maior variação em relação aquelas de porte médio e pequeno. Houve significativo ganho de peso de 8,75% ao fim dos seis meses de estudo, independente do ambiente, escore corporal e porte. Foi possível relacionar à variação da atividade vigorosa e leve moderada somada a vigorosa com o ganho de peso. Assim, conclui-se que até seis meses após a castração os animais não alteram os níveis de atividade física, mas apresentam significativo ganho de peso no mesmo período. / Neutering dogs is an elective procedure often performed, and its practice has been associated with the declined levels of physical activity and weight gain. The very majority of research involving physical activity is conducted through questionnaires that provide acceptable data, however those data are subjective. This study aimed to analyze quantitatively the physical activity and the weight gain in bitches before and after castration throughout accelerometer. Twenty one monitored bitches by accelerometer were evaluated in four stages: before, one month, three months and six months after ovariosalpingohysterectomy. The dogs were also evaluated in regards for the environment, weight, body condition score and size. There was no statistically significant reduction in levels of physical activity after castration. At the end of the six months post-operative sedentary, mild to moderate and vigorous activities remained the same as pre-castration versions. The environment did not influence the behavior of animals, since the activity levels remained very similar. Bitches overweight had a higher variation of activity in relation to bitches of ideal weight and large sized dogs greater variation regarding those medium and small-sized. There was significant weight gain of 8,75% at the end of the six months of study, regardless of the environment, body condition and size. It was possible to relate the variation of vigorous activity and mild to moderate added to vigorous activity with weight gain. Thus, it is concluded that up to six months after castration animals do not change the physical activity levels, but they present significant weight gain in the same period.