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Popular topics for upper-body resistance training involve the differences between hand positions, open versus closed chain exercises, and movement variations for the novice to the advanced. It was hypothesized that there will be no difference between closed (push-up) versus open (bench press) chain exercises for the primary muscle group activity nor would there be a difference between push-ups on the toes versus knees with respect to the percent contribution of each muscle. Surface muscle activity was measured for 8 upper-body and core muscles during a sequence of push-up and bench press variations with a normalized weight for 12 active men. Each participant completed push-ups and bench press exercises at each of 3 hand positions. The results demonstrated that there were few differences between closed versus open chain exercises for the primary muscle groups with the exception of core activation. In addition, in general, narrow hand positions yielded greater activation, and there were no significant differences between push-ups on the toes versus knees with respect to the percent contribution for the primary muscle groups. In conclusion, closed chain exercises may be preferred for functional training, and knee push-ups may be ideal as a novice push-up variation.
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INTRODUCTION: Exercise-associated muscle cramping (EAMC) is a poorly understood problem that is neuromuscular in origin. Ingestion of transient receptor potential (TRP) channel agonists has been efficacious in attenuating electrically induced muscle cramps. This study examines the effect of TRP agonist ingestion on voluntarily induced EAMC and motor function. METHODS: Study 1: Thirty-nine participants completed 2 trials after ingesting TRP agonist-containing active treatment (A), or vehicle (V) control. Cramping in the triceps surae muscle was induced via voluntary isometric contraction. Study 2: After ingesting A or V, 31 participants performed kinematic and psychomotor tests of manual dexterity. RESULTS: A increased precramp contraction duration (A, 36.9 ± 4.1 s; V, 27.8 ± 3.1 s), decreased cramp EMG area under the curve (A, 37.3 ± 7.7 %EMGmax ·s; V, 77.2 ± 17.7 %EMGmax ·s), increased contraction force to produce the cramp (A, 13.8 ± 1.8 kg; V, 9.9 ± 1.6 kg), and decreased postcramp soreness (A, 4.1 ± 0.3 arbitrary units (a.u.); V, 4.7 ± 0.3 a.u.). Kinematic and psychomotor tests were not affected. DISCUSSION: TRP agonist ingestion attenuated EAMC characteristics without affecting motor function. Muscle Nerve 56: 379-385, 2017.
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Eletromiografia/efeitos dos fármacos , Exercício Físico , Cãibra Muscular/tratamento farmacológico , Músculo Esquelético/efeitos dos fármacos , Proteínas do Tecido Nervoso/agonistas , Canais de Cátion TRPV/agonistas , Canais de Potencial de Receptor Transitório/agonistas , Adulto , Bebidas , Canais de Cálcio/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Ingestão de Alimentos/fisiologia , Eletromiografia/métodos , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Cãibra Muscular/etiologia , Fadiga Muscular/efeitos dos fármacos , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Canal de Cátion TRPA1 , Canais de Cátion TRPV/fisiologia , Canais de Potencial de Receptor Transitório/fisiologia , Adulto JovemRESUMO
In a previous study, we found that participants modified how they transitioned onto and off of ramp configurations depending upon the incline. While the transition strategies were originally attributed to ramp angles, it is possible that the plateau influenced the strategies since the final surface height also differed. Ultimately, for the current study, we hypothesized that an individual's transition strategies would have significant main effects for ramp angle, but not plateau height. Twelve healthy, young adults transitioned onto 3 distinct ramp configurations, a 2.4-m ramp angled at 12.5° ending at a plateau height of 53 cm, a 1.2-m ramp angled at 23.5° ending at a plateau height of 53 cm, and a 2.4-m ramp angled at 23.5° ending at a plateau height of 99.5 cm. Kinematics, kinetics, and muscle activity were measured during the stance phase before contacting the ramp. In support of our hypothesis, impact peak, active peak, and all of the muscle activity variables had a significant main effect for ramp angle, with greater vertical force peaks and muscle activity on steeper ramp transitions. These findings support our previous interpretation that individuals use estimations of ramp angle, not plateau height, to determine their transition strategies.
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Adaptação Fisiológica/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Caminhada/fisiologia , Adulto , Fenômenos Biomecânicos , Eletromiografia , Feminino , Humanos , MasculinoRESUMO
Falls are the leading cause of injury for all age groups. However, adults over 65 are at a higher risk, with one-third falling each year. Transitioning between level and hill surfaces poses a greater fall risk than walking on either surface alone. Previous studies found that young adults adopted a cautious gait pattern to mitigate this risk. As older adults typically employ a cautious pattern during level walking, we investigated how they modify their gait pattern to safely transition between surfaces. Twenty adults over the age of 65 transitioned onto and off of a 15° ramp while we recorded kinematics and muscle activity. During the level-to-downhill and uphill-to-level transitions, participants took slower, shorter steps indicative of an exaggerated cautious gait pattern. The older adults also exhibited greater muscle activity during the transitions, which may be due to muscle weakness requiring compensatory strategies to meet the greater demands of the task. However, the slower, shorter steps when transitioning from uphill to level suggest that these compensations may not always be adequate. Thus, it is important to consider the relationship between physical abilities and task demands in evaluating walking terrains that may be excessively difficult or dangerous for older adults.
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Marcha/fisiologia , Perna (Membro)/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Esforço Físico/fisiologia , Desempenho Psicomotor/fisiologia , Adaptação Fisiológica/fisiologia , Idoso , Feminino , Humanos , Masculino , Equilíbrio Postural/fisiologiaRESUMO
Many theories of motor control suggest that we select our movements to reduce energy use. However, it is unclear whether this process underlies short-term motor adaptation to novel environments. Here we asked whether adaptation to walking on a split-belt treadmill leads to a more economical walking pattern. We hypothesized that adaptation would be accompanied by a reduction in metabolic power and muscle activity and that these reductions would be temporally correlated. Eleven individuals performed a split-belt adaptation task where the belt speeds were set at 0.5 and 1.5 m s(-1). Adaptation was characterized by step length symmetry, which is the normalized difference in step length between the legs. Metabolic power was calculated based on expired gas analysis, and surface EMG was used to record the activity of four bilateral leg muscles (tibialis anterior, lateral gastrocnemius, vastus lateralis and biceps femoris). All participants initially walked with unequal step lengths when the belts moved at different speeds, but gradually adapted to take steps of equal length. Additionally, net metabolic power was reduced from early adaptation to late adaptation (early, 3.78 ± 1.05 W kg(-1); and late, 3.05 ± 0.79 W kg(-1); P < 0.001). This reduction in power was also accompanied by a bilateral reduction in EMG throughout the gait cycle. Furthermore, the reductions in metabolic power occurred over the same time scale as the improvements in step length symmetry, and the magnitude of these improvements predicted the size of the reduction in metabolic power. Our results suggest that increasing economy may be a key criterion driving locomotor adaptation.
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Adaptação Fisiológica , Metabolismo Energético , Caminhada/fisiologia , Adulto , Fenômenos Biomecânicos , Eletromiografia , Teste de Esforço , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Adulto JovemRESUMO
The American College of Sports Medicine and the United States Department of Health and Human Services advocate core training as a means to improve stability, reduce injury, and maintain mobility. There are countless exercises that target the primary core trunk muscles (abdominal and lumbar) with the aim of providing these benefits. However, it is unknown as to which exercises elicit the greatest activation thereby maximizing functional gains and peak performance. Thus, our purpose was to determine whether integration core exercises that require activation of the distal trunk muscles (deltoid and gluteal) elicit greater activation of primary trunk muscles in comparison with isolation core exercises that only require activation of the proximal trunk muscles. Twenty participants, 10 men and 10 women, completed 16 randomly assigned exercises (e.g., crunch, upper body extension, and hover variations). We measured muscle activity with surface electromyography of the anterior deltoid, rectus abdominus, external abdominal oblique, lumbar erector spinae, thoracic erector spinae, and gluteus maximus. Our results indicate that the activation of the abdominal and lumbar muscles was the greatest during the exercises that required deltoid and gluteal recruitment. In conclusion, when completing the core strength guidelines, an integrated routine that incorporates the activation of distal trunk musculature would be optimal in terms of maximizing strength, improving endurance, enhancing stability, reducing injury, and maintaining mobility.
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Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Músculos Abdominais/fisiologia , Análise de Variância , Eletromiografia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Introduction: Past research highlighted that group fitness is an ideal format to meet exercise prescription guidelines. To add, a group enhances exertion, enjoyment, and satisfaction. In the last five years, streaming (live classes on screen with other participants visible) and on demand (pre-recorded classes on screen without other participants visible) formats have grown in popularity. Our goal is to compare the physiological intensity and psychological perceptions of live group, live streaming, and non-live on demand classes. We hypothesize that live classes will have the greatest cardiovascular intensity, enjoyment, and satisfaction followed by streaming and finally on demand. Methods: Fifty-four adults between 18-63 years, who regularly participate in group fitness classes, recorded their heart rate with a chest transmitter during a mixed-martial arts cardiovascular class on consecutive weeks in random order. We calculated the mean, identified the max, and extracted the top 300 values (5 min) for comparison between conditions. Results: Following each class, the participants completed an online survey to evaluate their rate of perceived exertion, enjoyment, and satisfaction. Confirming our hypothesis, mean class heart rate and mean heart rate for the five minutes at the highest intensity were 9% greater during the live group format compared to both live streaming and non-live on demand (all values, p < 0.01). However, there was no difference in any heart rate variables between the streaming and on demand formats. Also, rate of perceived exertion, enjoyment, and satisfaction were all significantly greater during the live session compared to the home collections (all values, p < 0.05). Discussion: Streaming and on demand group fitness formats are viable options for meeting exercise prescription guidelines. But physiological intensity and psychological perceptions were greater during the live class format.
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In level running, humans and other animals store and recover elastic energy during each step. What role does elastic energy play during downhill and uphill running? We measured the fluctuations of the mechanical energy of the center of mass (CoM) of 15 human participants running at 3 m s(-1) on the level, downhill and uphill on a force-measuring treadmill mounted at 3, 6 and 9 deg. In level running, nearly symmetrical decreases and increases of the combined gravitational potential and kinetic (GPE+KE) energy of the CoM indicated equal possible elastic energy storage and recovery. However, asymmetrical fluctuations during hill running indicate reduced maximum possible elastic energy storage and return. We analyzed mechanical energy generation and dissipation during level and hill running by quantifying the anatomically estimated elastic energy storage (AEEE) in the arch and Achilles' tendon using peak ground reaction forces and anatomical characteristics. AEEE did not change with grade. At shallow downhill grades, the body must generate mechanical energy, though it dissipates more than it generates. At steeper downhill grades, little to no energy generation is required and only mechanical energy dissipation must occur. The downhill grade at which mechanical energy must no longer be generated occurs at approximately -9 deg, near the metabolically optimal running grade. At shallow uphill grades, mechanical energy must be generated to raise the CoM, and at steeper grades, additional energy must be generated to offset reduced elastic energy storage and return.
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Tendão do Calcâneo/fisiologia , Perna (Membro)/fisiologia , Corrida , Fenômenos Biomecânicos , Metabolismo Energético , Teste de Esforço , Feminino , Humanos , MasculinoRESUMO
The purpose of our study was to determine if altering the insoles within footwear or walking barefoot, as an attempt to increase or decrease cutaneous stimuli, would improve dynamic balance during a hill-walking task. We hypothesize that compared with foam insoles or iced bare feet, textured insoles or bare feet will result in greater speeds, longer step lengths, narrower step width, shorter stance time, and less tibialis anterior (TA), soleus (SOL), and lateral gastrocnemius (LG) activity during key gait cycle phases. Ten, healthy college students, 5 men and 5 women, completed the protocol that consisted of level walking and downhill transition walking in five different footwear insole or barefoot conditions. During level walking, conditions with the hypothesized greater cutaneous stimuli resulted in greater step length, which relates to a more stable gait. In detail, the texture insole condition average step length was 3% longer than the regular insole condition, which was 5% longer than the ice condition (p < .01). The same signals of increased stability were evident during the more challenging downhill transition stride. Step length during the barefoot condition was 8% longer than the ice condition (p < .05) and step width during the regular footwear condition was 5% narrower than the foam condition (p = .05). To add, during the preswing phase of level walking, TA activity of the textured insole condition was 30% less than the foam insole. Although our data show that footwear conditions alter gait patterns and lower leg muscle activity during walking, there is not enough evidence to support the hypothesis that textured insoles will improve dynamic balance as compared with other footwear types.
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Marcha , Sapatos , Caminhada , Adulto , Fenômenos Biomecânicos , Eletromiografia , Desenho de Equipamento , Feminino , Marcha/fisiologia , Humanos , Masculino , Músculo Esquelético/fisiopatologia , Propriocepção , Propriedades de Superfície , Caminhada/fisiologia , Adulto JovemRESUMO
Individuals must constantly modify their gait patterns to safely transition between different surfaces. The goal of the current study was to determine if gait changes could be detected two steps from a transition, and whether these changes scaled with the angle of the hill. We hypothesized that during the anticipation of uphill walking and the aftereffect of downhill walking, the magnitude of kinetic and electromyography changes would be greatest at steep hill angles and fewer steps from the transition. We collected force and electromyography data as participants walked on the level ground before an uphill ramp and after a downhill ramp. As hypothesized, there were significant main effects for both the number of steps and angle of the hill for the first vertical GRF peak, as well as lateral gastrocnemius and vastus lateralis activity. Overall, our results indicate that when transitioning to and from hills, anticipation and aftereffect responses occur at least two steps from the transition and are scaled to the angle of the hill.
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Adaptação Fisiológica/fisiologia , Marcha/fisiologia , Perna (Membro)/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Esforço Físico/fisiologia , Caminhada/fisiologia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
PURPOSE: Gait maturation, evidenced in, for example, the ability to walk over nonlevel surfaces, is an important indicator of typical development in children. Therefore, the purpose of this study was to compare the walking strategies used by children and adults during hill walking. METHODS: Temporal-spatial gait parameters and trial-to-trial coefficient of variation of these parameters were compared between 30 children (aged 3.5-5.5 years) and 30 adults during level and 15° hill walking. RESULTS: Compared with the adult group, the child group coefficient of variation was greater during all conditions. Furthermore, unique to the child group, there was a significant increase in variability during downhill walking. CONCLUSION: It is evident from the current results that children aged 3.5 to 5.5 years do not yet exhibit a mature gait and that downhill walking may increase fall risk. Attention should be given to gait variability and nonlevel walking when investigating or training children's gait.
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Transtornos Neurológicos da Marcha/diagnóstico , Marcha , Caminhada , Aceleração , Fatores Etários , Desenvolvimento Infantil , Pré-Escolar , Feminino , Transtornos Neurológicos da Marcha/patologia , Humanos , Masculino , TempoRESUMO
Healthy young adults transition between level and hill surfaces of various angles while walking at fluctuating speeds. These surface transitions have the potential to decrease dynamic balance in both the anterior-posterior and medial-lateral directions. Hence, the purpose of the current study was to analyze modifications in temporal-spatial parameters during hill walking transitions. We hypothesized that in comparison with level walking, the transition strides would indicate the adoption of a distinct gait strategy with a greater base of support. Thirty-four participants completed level and hill trials on a walkway with a 15-degree portable ramp apparatus. We collected data during 4 transition strides between level and ramp surfaces. In support of our hypothesis, compared with level walking, the base of support was 20% greater during 3 out of the 4 transition strides. In short, our results illustrate that healthy young adults did adopt a distinct gait strategy different from both level and hill walking during transitions strides.
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Marcha/fisiologia , Perna (Membro)/fisiologia , Esforço Físico/fisiologia , Análise e Desempenho de Tarefas , Caminhada/fisiologia , Adaptação Fisiológica/fisiologia , Adulto , Feminino , Humanos , MasculinoRESUMO
The purpose of this study was to investigate the feasibility, acceptability, and short-term adherence to an adult outdoor group sport play program designed to maximize enjoyment that was modified to incorporate COVID-19 risk mitigation strategies. We enrolled 17 healthy, but sedentary, central Pennsylvania adults (mean age = 31.6 ± 7.3) without obesity via mail advertisements to participate in four, 60-minute sessions of instructor-led modified sport games (e.g., handball, Ultimate Frisbee, soccer) over a two-week period in October 2020. Durign recrutiment and the study period, there were approximately 1000-2000 new cases of COVID-19 daily in central Pennsylvania . The overall adherence rate to the sessions was 91%, and no participants reported new or existing COVID-19 symptoms or diagnoses during the two-week study period or 10-days following the final session. Despite enforcing mandatory COVID-19 safety measures (e.g., universal masking, social distancing), the participants reported enjoying the program and feeling socially connected with one another, while perceiving the program to be safe. Additionally, all participants expressed a desire to participate again, if the program were offered in the future. These results suggest that an outdoor group sport play program for adults can be feasible, acceptable, and well-adhered to despite enforcing mandatory COVID-19 safety precautions. Physical activity programs similar to the one presented here may provide an easily-adaptable approach to outdoor physical activity during the current and potential future pandemics that have viral transmission characteristics similar to COVID-19.
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Despite the myriad benefits associated with regular physical activity (PA), few American adults accrue sufficient weekly PA. Although "lack of time" is often cited as a correlate of physical inactivity, a growing body of evidence suggests that, perhaps more importantly, people allocate their leisure-time to activities they find more enjoyable than PA. These findings underscore the need to devise physical activities that will be chosen over other enjoyable, but less healthy, behavioral alternatives. As a first step in this direction, we designed a group social PA play program for adults, known as PlayFit. The overarching philosophy of PlayFit is that fun and enjoyment are among the most important influences on PA adherence. In PlayFit, traditional sport games are modified to fulfill basic psychological needs, in a non-competitive, and non-contact environment. We will randomize 280 sedentary adults 18-50 years of age to 12-months of PlayFit or traditional group exercise, matching the groups on intensity, frequency, and duration. The primary outcomes include cardiorespiratory fitness (VO2peak), group adherence, and group enjoyment. We hypothesize that, at 6 months, cardiorespiratory fitness will have increased to the same extent in both groups, but at 12 months, only those randomized to PlayFit will have maintained their fitness through better adherence than Group Exercise - and this outcome will be mediated by enjoyment of the assigned group. Findings from this study could provide evidence that a focus on providing fun and enjoyable PA experiences for adults may be a viable route toward improving PA adherence. A simple, inexpensive PA intervention, such as PlayFit, may represent one such approach to do so.
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When climbing stairs, there are 2 practical strategies, contact each step with alternating feet (single) or contact every other step (double) with alternating feet. Our purpose was to evaluate the metabolic cost and muscular activity of these single and double stair-climbing strategies. We hypothesized that metabolic cost would not differ between the 2 strategies, because the subjects would complete the 2 protocols with a similar speed that would minimize cost. Likewise, we hypothesized that muscle activity during stance would not differ between the 2 stepping strategies. Twelve subjects completed baseline and experimental protocols. For the baseline protocol, the subjects walked up a stairwell with a single-step and a double-step strategy. For the experimental protocol, each subject walked on a treadmill inclined to the same degree as the stairs at the speed and step frequency determined from the baseline protocol. Every subject completed the baseline testing with a faster average speed during the double-step protocol. After mimicking each strategy with our experimental methods, we calculated that the double-step strategy would yield a greater use of metabolic energy, equal to approximately 1.0-1.3 kcalxkg-1xh-1, on average 70-90 additional kcalxh-1. This double-step strategy required a greater activity for propulsion during stance for the ankle and knee extensors. In summary, to maximize metabolic cost and muscular activity, we recommend a double-stair-climbing (skip a step) strategy.
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Músculo Esquelético/fisiologia , Esforço Físico/fisiologia , Eletromiografia , Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Feminino , Humanos , Perna (Membro)/fisiologia , Masculino , Movimento/fisiologia , Músculo Esquelético/metabolismo , Consumo de Oxigênio/fisiologia , Adulto JovemRESUMO
The growing prevalence and popularity of interval training necessitate additional guidelines in regard to maximal levels of time and intensity. PURPOSE: To correlate salivary hormones and time in varying heart-rate (HR) zones. The hypothesis was that chronic exercise durations >9% of total exercise time in the >90% maximum HR zone would lead to decreased variation in salivary cortisol concentration after exercise in a 2-bout high-intensity protocol compared with less or more time in this zone. METHODS: A total of 35 healthy adults who regularly exercised for an average of 8 hours per week recorded their HR during every training session for 3 weeks. Later, they completed an experimental day composed of two 30-minute high-intensity interval sessions separated by 4 hours of nonactive recovery. The authors collected saliva samples before, immediately following, and 30 minutes after each exercise session to assess changes in cortisol concentrations. RESULTS: There was a correlation between weekly time training at an intensity >90% maximum HR and the variables associated with overtraining. Salivary cortisol concentration fluctuated less in the participants who exercised in this extreme zone for >40 minutes per week (P < .001). CONCLUSION: Based on the current study data, for individuals who regularly exercise, 4% to 9% total training time above 90% maximum HR is the ideal duration to maximize fitness and minimize symptoms related to overreaching.
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Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Hidrocortisona/metabolismo , Saliva/metabolismo , Adulto , Afeto/fisiologia , Aptidão Cardiorrespiratória/fisiologia , Aptidão Cardiorrespiratória/psicologia , Metabolismo Energético , Exercício Físico/psicologia , Feminino , Treinamento Intervalado de Alta Intensidade/psicologia , Humanos , Masculino , Sono/fisiologia , Fatores de TempoRESUMO
BACKGROUND: Over 60 million Americans participate in running as a form of exercise or sport annually, making it the most popular form of physical activity in the country. Although there are numerous health benefits from a regular running routine, it is also an activity associated with a high risk of injury. Multiple factors, such as core muscle weakness and stride asymmetry, contribute to running injuries and loss of performance. The aim of this study was to assess how an integrated, functional core training intervention affects the components of performance (metabolic economy and speed) as well as a risk factor associated with injury (range of motion joint asymmetry). We hypothesized that economy, 5-km speed, and range of motion symmetry would increase in runners who added a 6-week integrated core-training intervention to their routine compared to a control group who simply maintained their current running routine. METHODS: Twelve, healthy adult runners participated in the study and six of these participants completed the exercise intervention. Heart rate data were collected to estimate metabolic economy while kinematic data were collected to calculate joint range of motion asymmetry. RESULTS: Our data demonstrated that running asymmetry decreased by a statistically significant 60% at the ankle in the sagittal plane while economy was 3% greater on both level and incline surfaces. CONCLUSIONS: In summary, runners who completed the 6-week integrated, functional training intervention improved economy, 5-km speed, and range of motion symmetry in comparison to the runners who simply maintained their current training routine.
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Desempenho Atlético , Treinamento Resistido/métodos , Corrida/fisiologia , Adulto , Tornozelo/fisiologia , Articulação do Tornozelo/fisiologia , Desempenho Atlético/fisiologia , Metabolismo Energético , Exercício Físico/fisiologia , Feminino , Frequência Cardíaca , Humanos , Consumo de Oxigênio/fisiologia , Amplitude de Movimento Articular/fisiologia , Esportes , Adulto JovemRESUMO
OBJECTIVE: How can we distinguish between a collection of individuals exercising alongside one another from group that is exercising 'together'? This question is central to research on the extent that individuals perceive their fitness settings to entail core features of groups. To advance understanding of the nature of groupness and its implications in exercise, the current study (a) evaluated a brief measure of groupness and (b) examined the extent that groupness predicted perceptions of exertion and affect. DESIGN: Participants included 633 exercisers (Mage = 33.92, SD = 11.05, 74% female) who completed surveys after group fitness classes (k = 34). MAIN OUTCOME MEASURES: Groupness, affect, exertion, and group cohesion. RESULTS: Exploratory structural equation modelling provided support for a two-factor solution reflecting entitativity and group structure as subdimensions of groupness. The groupness factors were differentially associated with theoretically relevant aspects of classes (e.g. synchronised movement), the individual (e.g. number of members interacted with), as well as group cohesion. Groupness also predicted perceived exertion and affect. CONCLUSION: Our research provides support for a brief measure of groupness, advances theory related to how individuals perceive exercise groups, and provides evidence regarding how broader experiences during exercise may relate to exercisers' perceptions of groupness.
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Exercício Físico/psicologia , Estrutura de Grupo , Relações Interpessoais , Adulto , Feminino , Humanos , Masculino , Inquéritos e QuestionáriosRESUMO
Group contexts such as fitness classes are popular forms of physical activity, and studying them can uncover new ways to promote exercise adherence. Focusing on the potential for group fitness experiences to vary from class-to-class, we examined how exercisers' dynamic perceptions of groupness relate to recalled perceptions of exercise enjoyment, affective valence, and exertion. These outcome variables are in focus because they are theoretically construed to be determinants of physical activity. Using an intensive sampling methodology across a two-week period, 97 adult exercisers (M age = 42.35 years) completed surveys following each fitness class attended (695 unique responses). Using multilevel confirmatory factor analysis, we confirmed a theorized two-factor structure of groupness at both the within-and between-person levels. Multilevel modeling revealed that class-to-class fluctuations in exercisers' perceptions of groupness explained a considerable portion of variance in recalled perceptions of exertion, enjoyment, and affective valence. Specifically, during classes in which exercisers' perceptions of groupness were relatively higher, exercisers reported more recalled enjoyment, affective valence, and exertion. Focusing on how variability in groupness perceptions may influence exercise adherence, these findings demonstrate the value in fitness classes feeling like authentic groups. In studying the dynamic aspects of group evaluations, the current study makes novel advancements to group theories applied to exercise settings. Perhaps most notably, individuals' variations in their cognitive evaluations of fitness groups were closely linked to their affective responses to exercise.