Self-selected Intensity Research Articles

Self-Selected Intensity and Adherence in a Campus Recreation Center with Novice, Female Weight Lifters: A Preliminary Investigation

In response to reports of lower resistance exercise participation in college-aged women, the present, preliminary investigation sought to examine the popular recommendation that self-selected intensity can have a positive impact on resistance exercise adherence. Fifty-three novice female weight lifters were asked to complete three sessions per week for six weeks in a campus recreation center. Results support previous research that novice or untrained individuals do not appear to self-select an intensity that meets common resistance training guidelines for strength and/or hypertrophic gains, although only slightly missing this mark. No differences were found in self-selection between weight or instruction types. Unlike previous anecdotal suggestions, self-selected intensity was not related to adherence; the average attendance was approximately seven sessions. Attrition was linear, and by week six, 95% of all participants had dropped out. In conclusion, despite popular thought, the present results do not support the concept that allowing students to choose their own intensity, alone, will enhance adherence to resistance exercise. Collegiate recreational staff and administrators can use these findings for novel ideas and directed efforts to enhance resistance exercise efforts in women.

A randomized controlled trial of dance exergaming for exercise training in overweight and obese adolescent girls.

Structured exergaming with prescribed moderate intensity physical activity has reduced adiposity among adolescents. The extent to which adolescents reduce adiposity when allowed to self-select intensity level is not known. The objective of the study was to examine the influence of exergaming on adolescent girls' body composition and cardiovascular risk factors. This randomized controlled trial assigned 41 overweight and obese girls aged 14 to 18 years to group-based dance exergaming (36 h over 3 months) or to a self-directed care control condition. Body size and composition were measured by anthropometry, dual-energy X-ray absorptiometry [%fat and bone mineral density {BMD}] and magnetic resonance imaging. Cardiovascular risk factors included blood pressure, cholesterol, triglycerides, glucose and insulin. Attrition was 5%. Using analysis of covariance controlling for baseline value, age and race, there were no significant condition differences. Per protocol (attended >75%), the intervention group significantly decreased abdominal subcutaneous adiposity and increased trunk and spine BMD (ps < 0.05). Per protocol (>2600 steps/session), the intervention group significantly decreased leg %fat and decreased abdominal subcutaneous and total adiposity (ps < 0.05). Exergaming reduced body fat and increased BMD among those adolescent girls who adhered. Further research is required before exergaming is recommended in clinical settings.

Self-selected intensity, ratings of perceived exertion, and affective responses in sedentary male subjects during resistance training.

[Purpose] This study examined the exercise intensity and psychophysiological responses to a self-selected resistance training session in sedentary male subjects. [Subjects and Methods] Twelve sedentary male subjects (35.8 ± 5.8 years; 25.5 ± 2.6 kg·m2) underwent four sessions at 48-h intervals: familiarization; two sessions of one repetition maximum test and a resistance training session in which they were told to self-select a load to complete 3 sets of 10 repetitions of chest press, leg press, seated rows, knee extension, overhead press, biceps curl, and triceps pushdown exercises. During the latter, the percentage of one repetition maximum, affective responses (feeling scale), and rating of perceived exertion (OMNI-RES scale) were measured. [Results] The percentage of one repetition maximum for all exercises was >51% (14–31% variability), the rating of perceived exertion was 5–6 (7–11% variability), and the affective responses was 0–1 point with large variability. [Conclusion] Sedentary male subjects self-selected approximately 55% of one maximum repetition, which was above the intensity suggested to increase strength in sedentary individuals, but below the recommended intensity to improve strength in novice to intermediate exercisers. The rating of perceived exertion was indicative of moderate intensity and slightly positive affective responses.

Feel your stride and find your preferred running speed.

ABSTRACTThere is considerable inter-individual variability in self-selected intensity or running speed. Metabolic cost per distance has been recognized as a determinant of this personal choice. As biomechanical parameters have been connected to metabolic cost, and as different running patterns exist, we can question their possible determinant roles in self-selected speed. We examined the self-selected speed of 15 terrestrial and 16 aerial runners, with comparable characteristics, on a 400 m track and assessed biomechanical parameters and ratings of pleasure/displeasure. The results revealed that aerial runners choose greater speeds associated with shorter contact time, longer flight time, and higher leg stiffness than terrestrial runners. Pleasure was negatively correlated with contact time and positively with leg stiffness in aerial runners and was negatively correlated with flight time in terrestrial runners. We propose the existence of an optimization system allowing the connection of running patterns at running speeds, and feelings of pleasure or displeasure.

An exploratory study examining the core affect hypothesis of the anti-depressive and anxiolytic effects of physical activity

We propose the core affect hypothesis that physical activity enhances valence and activation for people with depression symptoms but only valence for people with anxiety symptoms. In an exploratory study, affective valence and activation were assessed before and after a bout of exercise at a self-selected intensity in a small sample of inpatients. For most people with depressive disorders, affective valence (57%) and activation (55%) increased; whereas for people with anxiety disorders, half (50%) experienced an increase in affective valence, but only some (35%) experienced increased activation. Although exploratory and underpowered to test for statistically significant differences, these findings provide tentative support for more robust exploration into the core affect hypothesis. It may be that practitioners can enhance the impact of physical activity on depression or anxiety symptoms by applying the core affect hypothesis.

Self-selected intensity exercise in the treatment of major depression: A pragmatic RCT

Objective. The purpose of the study was to determine the therapeutic effect of physical exercise for patients with unipolar depression. Participants took part in an 8-week walking/running aerobic exercise program at a local sports club. Methods. Forty-six outpatients aged 18–65 years and diagnosed with mild to severe depression (ICD-10 criteria) were randomly assigned to an intervention group or wait list. Treatment as usual was continued. The Hamilton Rating Scale for Depression (HRSD-17) served as the main outcome measure. Secondary outcome measures were Beck Depression Inventory (BDI-II), Fitness Index (FI), and VO2 max as estimated by Urho Kaleka Kekkonen or UKK 2-km Walk Test. Results. Out of forty-six participants, 24% dropped out. Participants attended 58% of exercise sessions. All randomized participants were included in intention-to-treat (ITT) analysis. Analysis of covariance or ANCOVA showed a large reduction of depressive symptoms in HRSD-17 scores (Cohen's d: 1.8; mean change 8.2, p < .0001). BDI-II (Cohen's d: 0.50; mean change: 4.7, p = 0.09), FI scores (Cohen's d: 0.27; mean change: 5.3, p = 0.08), and VO2 max did not change significantly. Conclusions. We observed a large and clinically significant change in HRSD-17 scores. Moderate changes in BDI-II scores without clinical significance and small changes in physical fitness assessments were observed.

Effect of a 12-week aerobic training program on perceptual and affective responses in obese women.

[Purpose] The aim of this study was to observe the effect of self-selected intensity or imposed intensity during aerobic training on perceptual and affective responses in obese women. [Subjects] The study included 26 obese women aged 30–60 years. [Methods] The subjects were randomly divided into two groups, with 13 subjects in each group: self-selected intensity and imposed intensity (10% above ventilatory threshold) groups. All subjects completed an intervention program that lasted 12 weeks, with three exercise sessions a week. The rating of perceived exertion and affective responses (Feeling Scale and Felt Arousal Scale) were monitored in the first, sixth, and twelfth weeks. [Results] Significant differences were observed between groups in heart rate and rating of perceived exertion. The affective responses during exercise were more negative in the imposed intensity group. [Conclusion] Use of a self-selected exercise intensity can promote smaller negative affective responses during exercise and provide a sufficient stimulus for improvement in cardiorespiratory fitness.

Walking and Aerobic Capacity in Old Adults after Concentric and Eccentric Endurance Exercise at Self-Selected Intensities

Self-selected exercise intensity can be a useful exercise prescription tool for older adults; however, it is not known if it can elicit improvements in walking and aerobic capacity. In older adults, effects of concentric or eccentric endurance exercise at self-selected walking speed were examined on 1-mile indoor walk performance, predicted maximum oxygen uptake and physiological parameters. Twenty-four older adults (67 ± 4 years) completed 3 × 30 min treadmill walks per week for 12-weeks on level (LTW, n = 11, 0%) or downhill (DTW, n = 13, ﹣10%) treadmill gradient at a self- selected speed, which progressed every 4 weeks. Maximal oxygen uptake was predicted using a 1-mile walk at 4-week intervals with physiological responses recorded using a portable metabolic system. One-mile walking speed increased from baseline following 8- and 12-weeks (12 weeks: LTW: 13% ± 6%, DTW: 14% ± 9%, P < 0.01). Both groups increased predicted maximal oxygen uptake following 8-weeks of walking (LTW: 15% ± 15%; DTW: 23% ± 30%, P < 0.01). At 12-weeks, the 1-mile walk was performed with higher heart rates and minute ventilation (P < 0.01). It is concluded that an exercise programme of concentric or eccentric endurance exercise, at self-selected exercise intensity, is sufficient to elicit similar improvements in maximum oxygen uptake.

Physical and Psychological Effects from Supervised Aerobic Music Exercise

To assess the physical and psychological effects across 11 weeks of music-exercise sessions, the participants' training experience, and attitudes towards physical activity. The effect of different music information was also investigated. Overall, 146 sedentary volunteers were randomized into 4 exercise groups and each group received different music information. Physical capacity and psychological measures were obtained. Increased performance in oxygen uptake and flexibility and decreased blood pressure was found. Participants reported increased wellbeing and body-awareness, and an intention to remain physically active. No differences between groups were found. Music-exercise can be recommended to promote physical activity among sedentary individuals. The amount of musical information in synchronous music seems not to have any effects on self-selected intensity or physiological benefits.

Feasibility of using a compact elliptical device to increase energy expenditure during sedentary activities.

This study aimed to evaluate the feasibility of using a compact elliptical device to increase energy expenditure during sedentary activities. A secondary aim was to evaluate if two accelerometers attached to the elliptical device could provide reliable and valid assessments of participants' frequency and duration of elliptical device use. Physically inactive adults (n=32, age range=25-65) were recruited through local advertisements and selected using stratified random sampling based on sex, body mass index (BMI), and age. Indirect calorimetry was used to assess participants' energy expenditure while seated and while using the elliptical device at a self-selected intensity level. Participants also self-reported their interest in using the elliptical device during sedentary activities. Two Actigraph GT3X accelerometers were attached to the elliptical device to record time-use patterns. Participants expended a median of 179.1 kilocalories per hour while using the elliptical device (range=108.2-269.0), or a median of 87.9 more kilocalories (range=19.7-178.6) than they would expend per hour of sedentary sitting. Participants reported high interest in using the elliptical device during TV watching and computer work, but relatively low interest in using the device during office meetings. Women reported greater interest in using the elliptical device than men. The two accelerometers recorded identical time-use patterns on the elliptical device and demonstrated concurrent validity with time-stamped computer records. Compact elliptical devices could increase energy expenditure during sedentary activities, and may provide proximal environmental cues for increasing energy expenditure across multiple life domains.

Caffeine Ingestion and Cycling Power Output in a Low or Normal Muscle Glycogen State

Commencing selected workouts with low muscle glycogen availability augments several markers of training adaptation compared with undertaking the same sessions with normal glycogen content. However, low glycogen availability reduces the capacity to perform high-intensity (>85% of peak aerobic power (VO2 peak)) endurance exercise. We determined whether a low dose of caffeine could partially rescue the reduction in maximal self-selected power output observed when individuals commenced high-intensity interval training with low (LOW) compared with normal (NORM) glycogen availability. Twelve endurance-trained cyclists/triathletes performed four experimental trials using a double-blind Latin square design. Muscle glycogen content was manipulated via exercise-diet interventions so that two experimental trials were commenced with LOW and two with NORM muscle glycogen availability. Sixty minutes before an experimental trial, subjects ingested a capsule containing anhydrous caffeine (CAFF, 3 mg · kg(-1) body mass) or placebo (PLBO). Instantaneous power output was measured throughout high-intensity interval training (8 × 5-min bouts at maximum self-selected intensity with 1-min recovery). There were significant main effects for both preexercise glycogen content and caffeine ingestion on power output. LOW reduced power output by approximately 8% compared with NORM (P < 0.01), whereas caffeine increased power output by 2.8% and 3.5% for NORM and LOW, respectively, (P < 0.01). We conclude that caffeine enhanced power output independently of muscle glycogen concentration but could not fully restore power output to levels commensurate with that when subjects commenced exercise with normal glycogen availability. However, the reported increase in power output does provide a likely performance benefit and may provide a means to further enhance the already augmented training response observed when selected sessions are commenced with reduced muscle glycogen availability.

Is the Self-Selected Resistance Exercise Intensity by Older Women Consistent With the American College of Sports Medicine Guidelines to Improve Muscular Fitness?

The purpose of this study was to verify the self-selected intensity during resistance training (RT) in older women. Twenty healthy women (mean age, 65.6 years) underwent a 2-week familiarization period followed by 3 experimental sessions. During the first session, anthropometric measurements were taken. The second session involved completion of a 1 repetition maximum (1RM) test for the following exercises: chest press, leg press, lat pull-down, leg extension, lateral shoulder raise, leg curl, biceps curl, and triceps pushdown. Last, a single RT session was performed at a self-selected intensity. During the RT session, participants were instructed to self-select a load for performing 3 sets of 10-15 repetitions. Data were analyzed by mean (SD) and analysis of variance with repeated measures (p < 0.05). Global mean of the 3 sets was bench press 41.0% 1RM (11.9), leg press 43.0% 1RM (17.2), lat pull-down 47.2% 1RM (11.1), leg extension 33.0% 1RM (8.1), lateral shoulder raise 51.1% 1RM (12.1), leg curl 43.5% 1RM (8.8), biceps curl 48.0% 1RM (15.5), and triceps pushdown 51.7% 1RM (13.3); there were no significant differences between the sets (p > 0.05). These results indicate that inactive older women self-selected an intensity exercise during RT below the recommendation for improvements on muscle fitness in apparently healthy older adults. However, this intensity is recommended for very deconditioned individuals. Nevertheless, the use of self-selection strategy during an exercise program can have greater advantages because of its easy applicability, its positive relation with exercise adherence, and for promoting initial muscle conditioning in older adults. Furthermore, it is crucial to gradually increase the RT load to guarantee better and sustainable effects on muscle fitness. Finally, future studies are needed to establish the chronic effects of RT at self-selected intensity on muscle fitness and the functional health of older adults.

Affective change as a function of exercise intensity in a group aerobics class

This study examined, in a naturalistic setting, affective changes in 15 women. Measurements were obtained presession, postsession, and at 10-minute intervals during three aerobics sessions that were conducted at high (HI), low (LI) and self-selected (SS) intensities. The intensity was manipulated via changes in music tempo and movement size. Scores on the Feeling Scale (FS) and the Felt Arousal Scale (FAS) were subjected to two-way repeated measures analysis of variance (ANOVA). Circumplex models were constructed to display the path followed by the affective changes throughout the course of each exercise session. A main effect for time and condition emerged in that the FS scores were more positive in the SS intensity participants than in the LI participants, and the post-test FS scores were more favorable than they were at pretest or at 10 minutes, 20 minutes, 30 minutes, or 40 minutes. The FAS scores were higher in the SS intensity participants and HI participants than in the LI participants. A difference only emerged between the SS intensity and HI participants at the 20-minute interval. Variability in the circumplex profiles was evident across each intensity level and for each participant. The study supports and extends previous work in confirming that: (1) exercise can positively influence affective changes in ecologically valid settings; (2) a self-selected intensity is the most beneficial for producing affective changes; (3) idiosyncratic patterns of affective change occur when exercising at different intensities. The implications of these findings for exercise professionals are discussed.

Disentangling the effects of choice and intensity on affective response to and preference for self-selected- versus imposed-intensity physical activity

ObjectiveTo examine the independent effects of physical activity (PA) intensity and choice of PA intensity when comparing affective response to and relative preference for self-selected-intensity versus imposed higher intensity PA. DesignWithin-subjects experiment. MethodsTwenty-nine healthy, low-active women completed four PA bouts over two sessions. The first session consisted of a one-third mile self-selected-intensity treadmill walk during which the speed was recorded, but was not visible to the participants. The second session consisted of three, counterbalanced, one-third mile treadmill conditions: (a) self-selected intensity, (b) same intensity as recorded for the first-session-self-selected-intensity walk, but with the intensity imposed by the experimenter (i.e., yoked-self-selected intensity), and (c) intensity set at 20% higher than the first-session-self-selected-intensity walk (imposed higher intensity). Acute affective valence (pleasure/displeasure) was recorded prior to, during, and following each walking bout. Preference for each walking intensity was assessed using a behavioral-choice paradigm. ResultsContrary to hypotheses, there was no effect of condition on acute affective valence. However, consistent with hypotheses, there was a linear trend, F(1, 22) = 11.00, p = .003, indicating preference in descending order from self-selected-intensity to yoked-self-selected-intensity to imposed higher intensity PA. ConclusionsBoth choice over the intensity and a lower intensity per se contributed to greater preference for self-selected-intensity over imposed higher intensity PA among healthy low-active women; however, there was no evidence to support the notion that affective response to PA mediated this relationship.

Collective dynamics of populations of weakly correlated filaments of incoherent white light

We examined the dynamics of two populations of self-trapped filaments of spatially and temporally incoherent white light. The populations consisted of (i) independent filaments generated through self-trapping of incandescent speckles, and (ii) co-dependent filaments created through modulation instability of a broad incandescent beam. Both filament populations were positionally stable in conditions where individual pairs of self-trapped beams interact strongly. Both also acquired significantly broad intensity distributions, which were independent of their parent optical fields; a small but persistent number of high-intensity filaments was identified in both cases. These studies provide accessible routes to weakly correlated ensembles, insight into their collective behaviour such as self-stabilization and self-selected intensity distributions, and reveal intriguing similarities between the dynamics of two populations of different origins.

Cardiovascular Responses During Downhill Treadmill Walking at Self-Selected Intensity in Older Adults

Cardiovascular responses of older adults to downhill (DTW, -10% incline) and level treadmill walking (0%) at self-selected walking speed (SSWS) were examined. Fifteen participants (age 68 ± 4 yr, height 1.69 ± 0.08 m, body mass 74.7 ± 8.1 kg) completed two 15-min walks at their SSWS (4.6 ± 0.6 km/hr). Cardiovascular responses were estimated using an arterial-volume finger clamp and infrared plethysmography. Oxygen consumption was 25% lower during DTW and associated with lower values for stroke volume (9.9 ml/beat), cardiac output (1.0 L/min), arteriovenous oxygen difference (a-v O2 diff, 2.4 ml/L), and systolic blood pressure (10 mmHg), with no differences in heart rate or diastolic and mean arterial blood pressure. Total peripheral resistance (TPR) was higher (2.11 mmHg) during DTW. During downhill walking, an exercise performed with reduced cardiac strain, endothelial changes, and reduced metabolic demand may be responsible for the different responses in TPR and a-v O2 diff. Future work is warranted on whether downhill walking is suitable for higher risk populations.

Impact of a carbohydrate–electrolyte drink on ingestive behaviour, affect and self-selected intensity during recreational exercise after 24-h fluid restriction

This study examined the effects of a carbohydrate–electrolyte drink on voluntary fluid intake, affect and self-selected intensity during recreational exercise after fluid restriction. In a randomised counterbalanced design, ten physically active adults were dehydrated via a 24-h period of fluid restriction before completing two 20-min bouts of cardiovascular exercise, 20-min of resistance exercise and 20min on a cycle ergometer at a self-selected intensity with ad libitum access to water (W) or a carbohydrate–electrolyte solution (CES). Fluid restriction induced hypohydration of ∼1.2% initial body mass. Fluid intake during exercise was greater with CES (2105±363 vs. 1470±429mL; P<0.01) and resulted in more adequate hydration (−0.03±0.65 vs. −1.26±0.80%; P<0.01). Plasma glucose concentrations (4.48±0.40 vs. 4.28±0.32mmolL−1; P<0.01) and pleasure ratings (2.63±1.17 vs. 1.81±1.37; P<0.01) were greater with CES than W. Mean power output during exercise performed at a self-selected intensity was 5.6% greater with CES (171±63 vs. 162±60W; P<0.05). In physically active adults performing a ‘real-life’ recreational exercise simulation, CES resulted in more adequate hydration and an enhanced affective experience that corresponded with an increase in self-selected exercise intensity.

What is the effect of the early weight-bearing mobilisation without using any support after endoscopy-assisted Achilles tendon repair?

The aim of this study was to assess the effect of immediate weight-bearing mobilisation with intensive rehabilitation on muscle strength and lower extremity functional level after endoscopy-assisted Achilles tendon repairs. After warming up for 5 min at a self-selected intensity on a stationary bike 32 male patients were tested for bilateral peak concentric isokinetic ankle dorsi- and plantar-flexor torque, passive range of motion for ankle joint, one-leg hop for distance, single-leg vertical jump height, Achilles Tendon Total Rupture Score, and perceived function using the Foot and Ankle Outcome Score (FAOS). A series of paired sample t tests were used to compare side-to-side differences (p < 0.05). There were no significant differences in hop and jump tests, dorsi- and plantar-flexor isokinetic muscle strength, and dorsi- and plantar-flexion range of motion between the affected and unaffected side of the patients. Pain score of FAOS was 95 ± 8, other symptoms score was 92 ± 11, function in daily living score was 95 ± 6, function in sport and recreation was 85 ± 16, and Quality of Life score was 85 ± 12. The mean of the Achilles Tendon Rupture Score was 86. There was no significant difference in both ankle muscle strength and lower extremity functional level between the endoscopy-assisted repairs and the unaffected sides. The early tolerated weight-bearing mobilisation without cast-brace and/or special shoe at the first day after the surgery may easily provide to return the daily living activities. It improves muscle strength, functional level, and range of motion. Further comprehensive and prospective studies on large patients should be warranted to analyse and compare the clinical and functional results in patients with endoscopy-assisted Achilles tendon repair.

Comparison Between Nintendo Wii Fit Aerobics and Traditional Aerobic Exercise in Sedentary Young Adults

Exergaming is becoming a popular recreational activity for young adults. The purpose was to compare the physiologic and psychological responses of college students playing Nintendo Wii Fit, an active video game console, vs. an equal duration of moderate-intensity brisk walking. Twenty-one healthy sedentary college-age students (mean age 23.2 ± 1.8 years) participated in a randomized, double cross-over study, which compared physiologic and psychological responses to 30 minutes of brisk walking exercise on a treadmill vs. 30 minutes playing Nintendo Wii Fit "Free Run" program. Physiologic parameters measured included heart rate, rate pressure product, respiratory rate, and rating of perceived exertion. Participants' positive well-being, psychological distress, and level of fatigue associated with each exercise modality were quantified using the Subjective Exercise Experience Scale. The mean maximum heart rate (HRmax) achieved when exercising with Wii Fit (142.4 ± 20.5 b·min(-1)) was significantly greater (p = 0.001) compared with exercising on the treadmill (123.2 ± 13.7 b·min(-1)). Rate pressure product was also significantly greater (p = 0.001) during exercise on the Wii Fit. Participants' rating of perceived exertion when playing Wii Fit (12.7 ± 3.0) was significantly greater (p = 0.014) when compared with brisk walking on the treadmill (10.1 ± 3.3). However, psychologically when playing Wii Fit, participants' positive well-being decreased significantly (p = 0.018) from preexercise to postexercise when compared with exercising on the treadmill. College students have the potential to surpass exercise intensities achieved when performing a conventional standard for moderate-intensity exercise when playing Nintendo Wii Fit "Free Run" with a self-selected intensity. We concluded that Nintendo Wii Fit "Free Run" may act as an alternative to traditional moderate-intensity aerobic exercise in fulfilling the American College of Sports Medicine requirements for physical activity.

MEASUREMENT OF ENERGY EXPENDITURE WHILE PLAYING EXERGAMES AT A SELF-SELECTED INTENSITY.

Exergames have been suggested as a possible alternative to traditional exercise in the general population. The purpose of this study was to examine the heart rate (HR) and energy expenditure (EE) of young adults playing several different exergames, while self-selecting the component of the game to play and the intensity. A total of 117 participants, 18-35 years of age, were evaluated on one of four active video games. Participants were free to choose any component of the given game to play and they played at a self-selected intensity. The average HR and EE during the individual games were compared to resting conditions and to the American College of Sports Medicine (ACSM) guidelines. The HR and EE increased above resting conditions during each game (p<0.05). When the results of all games were combined, the HR was 125.4 ± 20.0 bpm and the average EE was 6.7 ± 2.1 kcal/min. This HR represents an average percent of heart rate reserve of 44.6 ± 14.1, high enough to be considered moderate intensity exercise. If performed for 30 minutes a day, five days per week, the average EE would be 1,005 kcals, enough to meet the ACSM recommendations for weekly EE. Therefore, at least some exergames could be a component of an exercise program.