A comparison of physiological intensity and psychological perceptions during three different group exercise formats.

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.

Adult outdoor group sport play during a pandemic: Feasibility, acceptability, and program adherence results from a study of modifications to mitigate COVID-19 risk.

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.

Comparative effectiveness of an adult social physical play versus traditional group exercise program for adherence and fitness: Protocol for a randomized-controlled trial.

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.

Exercise Time and Intensity: How Much Is Too Much?

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.

Perceptions of groupness during fitness classes positively predict recalled perceptions of exertion, enjoyment, and affective valence: An intensive longitudinal investigation.

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.

An integrated core training program improves joint symmetry and metabolic economy in trained runners.

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.

Group structure and entitativity in group fitness: considering groupness at within- and between-group levels.

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.

Muscle Activity Patterns do not Differ Between Push-Up and Bench Press Exercises.

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.

Ingestion of transient receptor potential channel agonists attenuates exercise-induced muscle cramps.

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.

Low load, high repetition resistance training program increases bone mineral density in untrained adults.

BACKGROUND: High load, low repetition resistance training increases BMD in untrained adults; however, many older and untrained adults cannot maintain this type of strenuous program. Our goal was to evaluate whether a low load, high repetition resistance training program would increase BMD in untrained adults. METHODS: Twenty sedentary, but otherwise healthy, adults (6 men and 14 women, age 28-63 yrs) completed a 27-week group exercise program. The participants were randomly assigned to one of two strength groups: one group completed full body, low load, high repetition weight training classes (S-WEIGHT), while the other group completed core focused fusion classes (S-CORE). Both groups also completed indoor cycling classes for cardiovascular conditioning. After a 3-week familiarization period, all participants completed a 12-week block of 5 fitness classes per week (3 cycling + 2 strength) and concluded with another 12-week block of 6 classes per week (3 cycling + 3 strength). We completed iDXA scans at baseline (week 3) and final (week 28). RESULTS: Compared to baseline, BMD significantly increased for S-WEIGHT in the arms (+4%, P<0.001), legs (+8%, P<0.01), pelvis (+6%, P<0.01) and lumbar spine (+4%, P<0.05), whereas BMD did not significantly change for S-CORE at any site. CONCLUSIONS: These results suggest that a low load, high repetition resistance training program may be an effective method to improve bone mass in adults.

Ramp Angle, Not Plateau Height, Influences Transition Strategies.

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.

Perceptions of the activity, the social climate, and the self during group exercise classes regulate intrinsic satisfaction.

Engaging in regular physical activity is a challenging task for many adults. Intrinsic satisfaction with exercise classes is thought to promote adherence to physical activity. This study examined the characteristics of exercise classes that impact within-person changes in intrinsic satisfaction over the course of an extended group exercise program. A 30-week physical activity trial was conducted with assessments at the end of each class. Community-living adults (n = 29) were instructed to complete at least six group exercise classes each week and, following each exercise class, complete a questionnaire asking about the characteristics of the class and the participant's evaluation of the class. Intrinsic satisfaction was high, on average, but varied as much within-person from class-to-class as it did between exercisers. Participants reported the greatest intrinsic satisfaction when classes placed greater emphasis on exercisers' involvement with the group task, feelings of competence, and encouragement from the instructor. For the most part, exercise classes that were more intense than usual were perceived by exercisers as less intrinsically satisfying. Some overall characteristics of the exercise classes were also associated with intrinsic satisfaction. The social and motivational characteristics of group exercise classes contribute to exercisers' intrinsic satisfaction with classes and attention to those dynamics, as well as the intensity of the exercise, may improve adherence for exercise regimens.

Older Adult Hill Transition Strategies are Determined by Task Demands and Cautious Gait Patterns.

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.

Segment lengths influence hill walking strategies.

Segment lengths are known to influence walking kinematics and muscle activity patterns. During level walking at the same speed, taller individuals take longer, slower strides than shorter individuals. Based on this, we sought to determine if segment lengths also influenced hill walking strategies. We hypothesized that individuals with longer segments would display more joint flexion going uphill and more extension going downhill as well as greater lateral gastrocnemius and vastus lateralis activity in both directions. Twenty young adults of varying heights (below 155 cm to above 188 cm) walked at 1.25 m/s on a level treadmill as well as 6° and 12° up and downhill slopes while we collected kinematic and muscle activity data. Subsequently, we ran linear regressions for each of the variables with height, leg, thigh, and shank length. Despite our population having twice the anthropometric variability, the level and hill walking patterns matched closely with previous studies. While there were significant differences between level and hill walking, there were few hill walking variables that were correlated with segment length. In support of our hypothesis, taller individuals had greater knee and ankle flexion during uphill walking. However, the majority of the correlations were between tibialis anterior and lateral gastrocnemius activities and shank length. Contrary to our hypothesis, relative step length and muscle activity decreased with segment length, specifically shank length. In summary, it appears that individuals with shorter segments require greater propulsion and toe clearance during uphill walking as well as greater braking and stability during downhill walking.

Pregnant women exaggerate cautious gait patterns during the transition between level and hill surfaces.

Falls are the leading cause of nonfatal injury across all age groups and a common incident for pregnant women. Thus, there is a critical demand for research to evaluate if walking strategies in pregnant women change throughout pregnancy in order to effectively intervene and minimize the incidence rate. The aim of the present study was to analyze modifications in temporal-spatial parameters as well as muscle activity during hill walking transitions in pregnant women between gestational week 20 and 32. Based upon previous literature, we hypothesized that in comparison to level walking, the transition strides of pregnant women would be distinct between trimesters in order to accommodate the physical changes within twelve weeks. Thirteen pregnant women completed a series of randomly assigned walking conditions on level and hill surfaces during gestational week 20 and 32. Our results demonstrated that pregnant women modulated their gait patterns throughout pregnancy with additional joint flexion as well as muscle activity at the ankle, knee and hip. In summary, pregnant women exaggerate cautious gait patterns by walking slower and wider with greater joint flexion and muscle activity in order to safely transition between level and hill surfaces.

Preferred step frequency during downhill running may be determined by muscle activity.

It is well established that metabolic cost is minimized at an individual's running preferred step frequency (PSF). It has been proposed that the metabolic minimum at PSF is due to a tradeoff between mechanical factors, however, this ignores muscle activity, the primary consumer of energy. Thus, we hypothesized that during downhill running, total muscle activity would be greater with deviations from PSF. Specifically, we predicted that slow step frequencies would have greater stance activity while fast step frequencies would have greater swing activity. We collected metabolic cost and leg muscle activity data while 10 healthy young adults ran at 3.0m/s for 5 min at level and downhill at PSF and ±15% PSF. In support of our hypothesis, there was a significant main effect for step frequency for both metabolic cost and total muscle activity. In addition, there was greater muscle activity in the stance phase during the slower step frequency while muscle activity was greater in the swing phase during the fast step frequency. This suggests that PSF is partially determined by the tradeoff between the greater cost of muscle activity in the swing phase and lower cost in the stance phase with faster step frequency.

Integration core exercises elicit greater muscle activation than isolation exercises.

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.

Learning to be economical: the energy cost of walking tracks motor adaptation.

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.

Altering footwear type influences gait during level walking and downhill transitions.

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.