Workout Duration Research Articles

Sports and exercise-related smartphone use is antagonistic to hedonic use in regular exercisers: A cross-sectional study examining the roles of exercise frequency and duration.

Hedonic smartphone use has been associated with dependence and addiction studied under the umbrella term Problematic Smartphone Use (PSU). Research usually explores total screen time as an index of PSU. A few studies suggest that exercise is inversely related to smartphone use time. However, it is unknown which primary characteristics of exercise behavior are related to more moderate smarthone use. Furthermore, the purpose of smartphone use, such as hedonic use associated with PSU versus utilitarian use, was not tested in the sports and exercise contexts. Hedonic use generally means playing with the smartphone for joy, distraction, and satisfaction. Utilitarian use implies practical and valuable use. There is a conjecture that sports involvement may foster utilitarian use through increased involvement in sports-related information-seeking, goal-setting, and self-monitoring. Therefore, we examined whether weekly exercise frequency, workout duration, and perceived exercise intensity relate to total daily smarthone and hedonic use and whether this relationship is mediated by sports-related utilitarian device use. We tested regularly exercising adults (n = 360, 132 males, M age = 39.0 ± 9.8, M weekly exercise = 5.8 ± 1.9) who volunteered for this study and provided demographic information about their exercise habits and smartphone use. The results revealed that all exercise parameters mediated the total daily smartphone use, with perceived exercise intensity being a negative predictor. Further, exercise frequency and duration (but not intensity) positively predicted sports-related smartphone use, which inversely predicted hedonic use. These results suggest that exercise parameters directly relate to daily smartphone use, which completely mediates hedonic use. These findings may partially account for the frequently reported inverse relationship between regular exercise and PSU by suggesting that the connection is mediated via sports-related smartphone use.

Impact of Remote Working on Recreational Physical Activity (RPA) Behaviours – a Case Study of the Covid-19 Lockdown in Poland

Abstract The aim of this article is to describe and explain changes in people’s recreational behaviours caused by the shift to remote work (RW) or work from home (WFH) due to lockdowns during the Covid-19 pandemic. A literature review revealed a cognitive, methodological and applicative gap in this area. This relationship has not been analysed so far, particularly among Poles. The authors developed an electronic questionnaire using a framework designed to study RPA behaviours. A survey based on the questionnaire was conducted from 20 May to 31 Oct. 2020 and included 533 respondents, with 371 people experiencing changes at work, 280 of whom shifted to RW/WFH. A combination of quantitative and qualitative data analysis methods (descriptive statistics and content analysis techniques, affinity diagram, relationship diagram) was used to analyse the survey results. The results of the qualitative analysis allowed a description of changes in the respondents’ lifestyles induced by the transition to RW/WFH. The results of the quantitative data analysis showed unequivocally that taking up RW/WFH had a negative impact on RPA behaviours. The frequency and duration of workouts decreased. The novelty lies in demonstrating the relationship between remote working/work from home and RPA and the inventive methodological approach. The results are universal and can be used to design work-life balance programmes for remote employees.

Exercise and Health: Examination of the Relationship between Gym Attendance, Mental Health, and Perceptions of Body Image

The present study examined the relationship between frequency of gym attendance, workout length, happiness, and perceptions of self-esteem, appearance, and the benefits of exercise. A total of 85 participants (48 females, 37 males) completed eight self-report measures, including the Rosenberg Self-Esteem Scale (Rosenberg, 1989), the Subjective Happiness Scale (Lyubomirsky & Lepper, 1999), the Appearance Anxiety Inventory (Veale et al., 2013), the Body Dysmorphic Disorder Questionnaire (Phillips, 2005), the Muscle Dysmorphic Disorder Inventory (Zeeck et al., 2018), the Exercise Benefits/Barriers scale (Sechrist et al., 1987), and two additional measures reporting weekly gym attendance and duration. Results showed that the frequency of weekly gym attendance and time spent in the gym had no relationship to Body Dysmorphic Disorder (BDD), Muscle Dysmorphia (MD), and appearance anxiety. Time spent in the gym had no relationship to BDD, MD, and appearance anxiety. However, both frequency of gym attendance and workout duration had a strong positive relationship to beneficial views of exercise and self-esteem. Lastly, happiness was found to have no relationship with the frequency of gym attendance but had a positive relationship with the amount of time spent at the gym. Overall, it was concluded that gym attendance in general helps to improve certain aspects of mental health, perhaps through creating a more positive self-perception and increased subjective happiness

Spinal column and midbrain integration for long duration space missions

Background: Deep space missions produce atrophied postural muscles and cognitive and proprioception losses. Lumbar and hip injury as well as limbic system dysregulation may result. In microgravity, the Neutral Body Position is the spinal baseline for the prone-position cycle, where the astronaut’s lumbar muscles and audio and visual-spatial centers can be informed through a virtual reality interface. Methods: The exercise can be reproduced as a low-fidelity space simulation in a epsom-salt float tank. MRI and ultrasound imaging of the spine at the start of the 4-week program can be compared to the imaged results upon program completion. Any contractile tightening would be evident in shortened IVD (intervertebral distances) in post-procedure MRI results. The terrestrial gravity cycling instrument establishes an effective baseline for determining anthropomorphic tolerances, the necessary workout duration and resistance levels in zero gravity. Results: An exercise regimen performed on an ergonomically-designed cycle can limit the stresses to demineralized postural bones thus reducing the risk of in-flight and post-flight fractures. The redistribution of spinal fluids is a specific focus of this exercise instrument. It's postulated that the secondary effect of reduced spinal fluid shifts are lower optic nerve and cranial pressures and the tertiary effect is the reduction of neuro-cognitive and cardio-vascular stresses brought on by weightlessness. Conclusions: The biomechanism of spinal fluid’s dynamic flow across a lower pressure gradient may be the cause of increased fluid volume in the spinal canal. This cycling exercise lessens the physical impact to areas of BMD depletion such as the hip socket. The exercise can maintain spinal flexibility, fluid stasis and posture. Human body systems affected by microgravity could be assisted with Virtual Reality (VR) inputs. The limbic system receives comprehensive, targeted sensory information that enables reorganization of neuronal networks that may serve to change dysregulated human immune, spatio-temporal, and cognitive systems.

Paper 58: Against Surgeons’ Advice: The Return to Sport in High Demand Weightlifters Following Anatomic Total Shoulder Arthroplasty at Average 3.6 Years Follow-up

Objectives: Return to sport in high-demand weightlifters following total shoulder arthroplasty has rarely been investigated, as most surgeons recommend against returning to heavy lifting postoperatively. The purpose of this study is to determine the incidence of return to sport, patient reported outcomes, patient satisfaction, performance, and failures in a specific population of high demand weightlifters that continue lifting after undergoing total shoulder arthroplasty. Methods: Retrospective review of a specific population of high demand weightlifters that underwent anatomic total shoulder arthroplasty with minimum one-year clinical follow up was conducted. Prospective surveys determining pre- and postoperative participation in weightlifting included maximum weight, frequency, and duration of workouts, Single Assessment Numeric Evaluation (SANE), patient satisfaction, and post-operative range of motion were collected. Secondary outcomes included failure, revision surgery, risk factors for not returning to weightlifting, and performance measured as percentage of prior maximum bench press. Bivariate and multivariate analysis was performed to compare cohorts and identify risk factors, respectively. Results: Forty-two shoulders in 36 patients who met inclusion criteria (avg age 57.9 years, 97% male). No patient underwent revision surgery at average 3.6 year follow up (1 to 7 years, SD 1.9 years). The majority of patients (23/42 shoulders) report returning to heavy weightlifting postoperatively against senior surgeon’s recommendations. Mean SANE score for current weightlifters and retired weightlifters were 86.9 and 91.6, respectively (P = 0.148). In the weightlifting cohort, only 78.3% of patients achieved patient-acceptable symptom state (PASS) threshold for SANE compared to 89.5% of patients (p = .332) in the retired cohort. Patient satisfaction and return to sport satisfaction in current weightlifting shoulders were good-to-excellent in 91.3% (P= 0.922) and 82.6% (P = 0.972) respectively. Patients who continued lifting reported substantially decreased maximum weight in all lifts compared to pre symptomatic maximum. Conclusions: This data provides insight for surgeons on the expected activity level of prior high demand weightlifters. Against their surgeon’s recommendations, most patients who participated in preoperative weightlifting returned to high demand weightlifting after surgery, but patients demonstrated lower lifting performance postoperatively. There were no early clinical catastrophic failures with high patient reported outcomes. While caution is still advised with returning to heavy weightlifting, the current data highlights the advances of modern fixation techniques, fourth generations implants, and diminished lifting capacity after surgery, which likely play a role in the high implant survivorship in this cohort.

Prediction of metabolic activity of rowing athletes based on serum biochemical analysis

Determination of the metabolic state is an important topic in sports medicine. Biochemical and hematological blood parameters reflect the predominance of anabolic or catabolic processes in metabolism, these parameters depend on intensity and duration of workouts. The aim of the present study was to determine whether metabolic processes are dominant. 21 male rowing athletes (age: 22.55 ± 3.68 years, height: 189.62 ± 6.34 cm, weight: 88.65 ± 8.55 kg) participated in the experiment. Monitoring of blood concentrations in samples collected from participating athletes and measuring workout intensity led to the use of a linear-discriminant function. With this technique, the eight main blood count parameters: creatinine (p < 0.001), uric acid (p < 0.001), urea (p < 0.001), testosterone (p < 0.001), ALP (p < 0.001), albumin (p < 0.05), total calcium (p < 0.05), and total protein (p < 0.05) for the prediction of the metabolic state have been determined. The reliability of test results using a linear-discriminant function for the prediction of the metabolic state in athletes was supported by a strong positive correlation (r = 0.88, p < 0.001) with the results of the neuroendocrine system activity assessments. The accuracy of the metabolic state prediction was 91.8%.

Workout Detection by Wearable Device Data Using Machine Learning

There are many reports that workouts relieve daily stress and are effective in improving mental and physical health. In recent years, there has been a demand for quick and easy methods to analyze and evaluate living organisms using biological information measured from wearable sensors. In this study, we attempted workout detection for one healthy female (40 years old) based on multiple types of biological information, such as the number of steps taken, activity level, and pulse, obtained from a wristband-type wearable sensor using machine learning. Data were recorded intermittently for approximately 64 days and 57 workouts were recorded. Workouts adopted for exercise were yoga and the workout duration was 1 h. We extracted 3416 min of biometric information for each of three categories: workout, awake activities (activities other than workouts), and sleep. Classification was performed using random forest (RF), SVM, and KNN. The detection accuracy of RF and SVM was high, and the recall, precision, and F-score values when using RF were 0.962, 0.963, and 0.963, respectively. The values for SVM were 0.961, 0.962, and 0.962, respectively. In addition, as a result of calculating the importance of the feature values used for detection, sleep state (39.8%), skin temperature (33.3%), and pulse rate (13.2%) accounted for approximately 86.3% of the total. By applying RF or SVM to the biological information obtained from the wearable wristband sensor, workouts could be detected every minute with high accuracy.

Is Rating of Perceived Exertion a Valuable Tool for Monitoring Exercise Intensity During Steady-State Conditions in Elite Endurance Athletes?

Rating of perceived exertion (RPE) is a widely used tool to assess subjective perception of effort during exercise. The authors investigated between-subject variation and effect of exercise mode and sex on Borg RPE (6-20) in relation to heart rate (HR), oxygen uptake (VO2), and capillary blood lactate concentrations. A total of 160 elite endurance athletes performed a submaximal and maximal test protocol either during cycling (n = 84, 37 women) or running (n = 76, 32 women). The submaximal test consisted of 4 to 7 progressive 5-minute steps within ∼50% to 85% of maximal VO2. For each step, steady-state HR, VO2, and capillary blood lactate concentrations were assessed and RPE reported. An incremental protocol to exhaustion was used to determine maximal VO2 and peak HR to provide relative (%) HR and VO2 values at submaximal work rates. A strong relationship was found between RPE and %HR, %VO2, and capillary blood lactate concentrations (r = .80-.82, all Ps < .05). The between-subject coefficient of variation (SD/mean) for %HR and %VO2 decreased linearly with increased RPE, from ∼10% to 15% at RPE 8 to ∼5% at RPE 17. Compared with cycling, running induced a systematically higher %HR and %VO2 (∼2% and 5%, respectively, P < .05) with these differences being greater at lower intensities (RPE < 13). At the same RPE, women showed a trivial, but significantly higher %HR and %VO2 than men (<1%, P < .05). Among elite endurance athletes, exercise mode influenced RPE at a given %HR and %VO2, with greater differences at lower exercise intensities. Athletes should manage different tools to evaluate training based on intensity and duration of workouts.

Impact of using wearable devices on psychological Distress: Analysis of the health information national Trends survey

AimThis study explores the possible impact of wearables on psychological distress and their implications on designs. MethodThe study conceptualizes and tests two exploratory models by analyzing the US-based Health Information National Trends Survey of 2019 and 2020. Six variants from the databases were used in the study as predictors. We used models 4 and 6 of the Hayes PROCESS macros to test our conceptual parallel and sequential mediation models, respectively. ResultsThe finding indicates significant and negative indirect effects of ‘Use of wearable device’ on ‘Psychological distress.’ In parallel mediation models, ‘self-care’ and ‘health perception’ were noted to be significant mediators. Wearable devices were associated with improved ‘Health perception,’ ‘Self-care,’ and longer ‘workout duration,’, which in turn helped reduce ‘psychological distress’ (better mental health). The sequential mediation model captured the indirect effect of ‘Use of wearable device’ on ‘Psychological distress’ when sequentially mediated by ‘workout duration,’ ‘BMI,’ ‘self-care,’ and ‘health perception’ in the given order. ConclusionAs the adoption of digital wearables is increasing due to their growing potential to augment physiological and psychosocial health, it is critical that these technologies are designed to address the needs of users from diverse backgrounds (race, education level, age).

Pre-Exercise Nutrition Habits and Beliefs of Endurance Athletes Vary by Sex, Competitive Level, and Diet

Objective The purpose of this study was to determine the self-reported beliefs and practices relating to pre-exercise nutrition intake among endurance athletes of varying ages and competitive levels and examine differences based on sex, competitive level, and habitual dietary pattern. Method An anonymous online survey was circulated internationally in English and completed by 1950 athletes of varying competitive levels (51.0% female, mean age 40.9 years [range 18:78]). Survey questions included training background, determinants of pre-exercise nutrition intake and composition, and timing relative to exercise. Results Prior to morning exercise, 36.4%, 36.0%, and 27.6% of athletes consumed carbohydrate-containing food/drinks before almost every workout, some of the time, and never/rarely, respectively, with significant effects of sex (p < 0.001, Cramer’s V (ϕc) = 0.15) and competitive level (p < 0.001, ϕc = 0.09). Nutritional intake before exercise varied based on workout duration for 47.6% of athletes, with significant effects of sex (ϕc = 0.15) and habitual diet (ϕc = 0.19), and based on workout intensity for 39.1% of athletes, with significant effects of sex (ϕc = 0.13) and habitual diet (ϕc = 0.17, all p < 0.001). Additionally, 89.0% of athletes reported using at least some type of dietary supplement (including caffeine from coffee/tea) within 1 hour before exercise. Conclusions Overall, nearly all factors measured relating to pre-exercise nutrition intake varied by sex, competitive level, habitual dietary pattern, and/or intensity/duration of the training session and suggest a large number of athletes may not be following current recommendations for optimizing endurance training adaptations.

Exposure to nickel from the metal equipment in the gym

It remains unclear whether gym customers are exposed to any nickel from the metal equipment and if the exposure is associated with the duration of contact. Therefore, the aim of this study was to ascertain exposure to nickel measured through nickel concentration in the hair in those exercising in a fitness gym. We enrolled 100 amateur athletes in one of the gyms in Almaty, Kazakhstan (all men, median age 30 (interquartile range (IQR) 10) years), exercising from 2 to 7 days a week for 40 to 180 minutes and their age- and sex-matched controls who did not exercise. All subjects filled in the questionnaires on the exercising patterns, smoking and occupational exposure and then donated 0.25 g of head hair, in which nickel was measured using atomic absorption spectrophotometry. Hair nickel concentration ranged from 0 to 8.5 µg/g with notable left-skewness towards low concentrations in both groups. Hair nickel concentration was not associated with age, smoking or occupation, but was significantly lower in amateur athletes compared to controls (median 0 (IQR 0.5) vs. 0.9 (IQR 1.4) µg/g). More days a week in a gym, longer workout history, longer workout duration or supplements use did not increase the probability of being stratified in a high-exposure subgroup (defined as 75th percentile of hair nickel concentration and higher); however, there were more smokers in a low-exposure group (p&lt;0.05). With the mixed pattern of exposure, gym goers may be unlikely exposed to more nickel from the metal equipment in the gym, however the exposure may depend on the specific alloy composition.

The Effects of Knowledge, Lack of Knowledge, and Deception on Rate of Perceived Exertion and Performance During Workouts

The purpose of this study is to examine how knowledge, lack of knowledge, and deception affect the rate of perceived exertion (RPE) and actual performance of moderately trained teenagers engaged in sprint training. This study has two hypotheses. The first hypothesis is that athletes who do not know their sprint duration will have a lower reported RPE and actual performance, compared to athletes who are aware of their sprint duration. Our second hypothesis is that athletes deceived with a lower sprint duration will report a higher RPE and performance compared to when they have knowledge of their duration. The order of the experimental conditions was knowledge, deception, and then lack of knowledge. Participants started from the midfield line of an indoor soccer field and ran to the end of the field and back to midfield ten times for all conditions. While on their way back, they reported their RPE to an assigned assistant who was timing them. We found that participants ran the slowest and reported the lowest RPE throughout the ten sprints in the lack of knowledge condition. We also found that the knowledge condition had a slower average sprint time than the sprints during deception, but the knowledge condition yielded the fastest and most consistent speeds. Coaches should strongly consider telling their athletes the truth about workout duration since our study along with many others suggests that it is the best way to maximize performance and RPE.

Testosterone and Cortisol Responses to Five High-Intensity Functional Training Competition Workouts in Recreationally Active Adults.

To determine the salivary steroid response to high-intensity functional training (HIFT) competition workouts, saliva samples were collected from ten recreationally trained male and female competitors during a 5-week (WK1–WK5) international competition. Competitors arrived at their local affiliate and provided samples prior to (PRE) their warm-up, immediately (IP), 30-min (30P), and 60-min (60P) post-exercise. Samples were analyzed for concentrations of testosterone (T), cortisol (C), and their ratio (TC). Generalized linear mixed models with repeated measures revealed significant main effects for time (p < 0.001) for T, C, and TC. Compared to PRE-concentrations, elevated (p < 0.05) T was observed at IP on WK2–WK5 (mean difference: 135–511 pg·mL−1), at 30P on WK3 (mean difference: 81.0 ± 30.1 pg·mL−1) and WK5 (mean difference: 56.6 ± 22.7 pg·mL−1), and at 60P on WK3 (mean difference: 73.5 ± 29.7 pg·mL−1) and WK5 (mean difference: 74.3 ± 28.4 pg·mL−1). Compared to PRE-concentrations, elevated (p < 0.05) C was noted on all weeks at IP (mean difference: 9.3–15.9 ng·mL−1) and 30P (mean difference: 6.0–19.9 ng·mL−1); significant (p < 0.006) elevations were noted at 60P on WK1 (mean difference: 9.1 ± 3.0 ng·mL−1) and WK5 (mean difference: 12.8 ± 2.9 ng·mL−1). Additionally, TC was significantly reduced from PRE-values by 61% on WK1 at 60P (p = 0.040) and by 80% on WK5 at 30P (p = 0.023). Differences in T, C, and TC were also observed between weeks at specific time points. Although each workout affected concentrations in T, C, and/or the TC ratio, changes appeared to be modulated by the presence of overload and workout duration. During periods of elevated training or competition, athletes and coaches may consider monitoring these hormones for consistency and as a means of assessing workout difficulty.

Perceived Exertion As A Monitoring Strategy During Crossfit®

Facing harsh criticism of potentially causing injury, CrossFit® (CF) may benefit from the inclusion of appropriate monitoring strategies. Rate of perceived exertion (RPE) is a monitoring strategy commonly used for both quantification and modulation of workloads during exercise and sports training. Despite its widespread use in CF investigations, the validity of RPE as a monitoring strategy in CF training remains untested. PURPOSE: To assess the utility of RPE as a monitoring strategy during CF training. METHODS: Six males (height, 182.8±8.6 cm; weight, 84.3±12.4 kg; and age, 25.0±5.4 years) participated in three weeks (5 days/week) of CF training. Following each training session, RPE, workout duration (Dura), and immediate post-exercise heart rate (THR) were recorded. Dura and THR were used to quantify the workload (WL) for each session. Means for RPE, Dura, THR, and WL were calculated for week 1 and week 3 of training. The Profile of Mood States (POMS) questionnaire was administered pre-week 1 and post- week 3. A repeated measures MANOVA with Tukey post-hoc adjustments was used to assess differences in training session variables between weeks 1 and 3. Linear regression of mean RPE and WL were compared between weeks 1 and 3. POMS outcomes were compared between weeks 1 and 3 using magnitude-based inferences of each subscales’ minimum clinically important difference (MCID). RESULTS: There are increases in mean session THR (%Δ=+6.2%; F=1.19, p=0.324), Dura (%Δ=+17.3%; F=4.55, p=0.086), and WL (%Δ=+23.9%; F=8.14, p=0.036) from week 1 to 3. In contrast, mean session RPE decreased (%Δ=-4.9%; F=1.42, p=0.183) between these weeks. RPE was a better predictor of WL during week 3 compared to week 1 (week 1: r=0.364, R2=13.5%, p=0.048; week 3: r=0.614, R2=37.7%, p=0.001; ΔR2=+24.2%). For POMS outcomes, total mood disturbance (2.69 foldΔ; 87.6% likelihood), tension-anxiety (3.13 foldΔ; 90.7% likelihood), and vigor-activity (3.25 foldΔ; 94.9% likelihood) subscales most likely highlight meaningful negative changes. CONCLUSION: RPE has the potential to be a useful monitoring strategy for incorporation into CF training. Questions still remain as to whether or not RPE is sensitive enough to detect early signs of overreaching during CF training.

Session-RPE for quantifying the load of different youth basketball training sessions.

The aim of the study was to evaluate youth basketball training, verifying the reliability of the session-RPE method in relation to session duration (< and ≥ 80 minutes) and workout typology (reduced and high warm-up, conditioning, technical, tactical, game portions within a single session) categories. Six male youth basketball players (age, 16.5±0.5 years; height, 195.5±6.75 cm; body mass, 93.9±10.9 kg; and body mass index, 23.6±2.8 kg.m-2) were monitored (HR, type and duration of workouts) during 15 (66 individual) training sessions (80±26 minutes). Edwards’ HR method was used as a reference measure of internal training load (ITL); the CR-10 RPE scale was administered 30 minutes after the end of each session. The results obtained showed that all comparisons between different session durations and workout portions revealed effects in term of Edwards’ ITLs except for warm-up portions. Moderate to strong relationships between Edwards’ and session- RPE methods emerged for all sessions (r = .85, P < .001), player’s sessions (r range = .79 - .95, P < .001), session durations (< 80 minutes: r = .67, P < .001; ≥ 80 minutes: r = .75, P < .001), and workout portions (r range = .78 - .89, P range = .002 - < .001). The findings indicated that coaches of youth basketball players can successfully use session-RPE to monitor the ITL, regardless of session durations and workout portions.

Nitric Oxide/Arginine: Is Cardiovascular Modulation Effects in Athletes Supplementation?

Dietary nitrates and L-Arginine have been increasingly recognized to play a promising role as sport dietary supplementation, getting more and more popular as ergogenic aids, namely, substances used with regard to performance enhancement. Inorganic nitrate (NO3-) is abundant in numerous foodstuffs and is convertible into nitrite (NO2-) following ingestion. Nitrite, in turn, can be metabolized into nitric oxide (NO), one of the most widespread signaling molecules, taking part in virtually every cellular and organic functions, most notably blood flow regulation and vasodilation, mitochondrial respiration, platelet function and metabolic homeostasis. L-Arginine is a conditionally essential amino acid that has been target of considerable attention as the main precursor of NO, revealing other promising potential effects on growth hormone (GH) release, promotion of creatine synthesis, all leading to possible exercise tolerance and muscle efficiency benefits, impairment of O2 uptake (cost of submaximal exercise) and rise in workout duration before fatigue. Accordingly, the purpose of this review is to provide an overview on the accumulating evidence concerning not only the importance of NO and its associated precursors in exercise and sports performance, but also the inherent cardiovascular modulation during workout, as well as ascertain the possible benefits and hazards, never despising the crucial role ascribed to sports nutrition professionals.

The Salivary Testosterone and Cortisol Response to Three Loading Schemes

This aim of this study was to examine the free hormone (in saliva) responses to squat workouts performed by recreationally weight-trained males, using either a power (8 sets of 6 reps, 45% 1 repetition maximum [1RM], 3-minute rest periods, ballistic movements), hypertrophy (10 sets of 10 reps, 75% 1RM, 2-minute rest periods, controlled movements), or maximal strength scheme (6 sets of 4 reps, 88% 1RM, 4-minute rest periods, explosive intent). To determine the relative importance of the different training variables, these schemes were equated by workout duration with the power and strength schemes also equated by load volume. Salivary testosterone (T) and cortisol (C) both increased following the hypertrophy scheme (P < 0.05), with little to no hormonal change across the power and maximal strength schemes (P > 0.05). In general, the postexercise T and C responses to the hypertrophy scheme exceeded the other two schemes (P < 0.05). The greater volume of load lifted in the hypertrophy protocol over the same workout duration may explain the endocrine differences observed. The similar T and C responses to the power and maximal strength schemes (of equal volume) support such a view and suggest that differences in load intensity, rest periods, and technique are secondary to volume. Because the acute hormonal responses to resistance exercise contribute to protein metabolism, then load volume may be the most important workout variable activating the endocrine system and stimulating muscle growth.

Exercise-Related Injury in Women: Prevention and Recovery

Exercise, with its numerous benefits to health and well-being, also carries risk for injury. Exercise-related injuries fall into two major categories -- acute injuries (e.g., sprains and strains) and overuse injuries (e.g., tendonitis). This article focuses on conditions most common in recreational athletes, as well as those that disproportionately affect female athletes. Acute Injuries Acute injuries usually result from trauma, such as stepping on an uneven surface or making contact with another player. An exception is the potentially season- or career-ending anterior cruciate ligament (ACL) injury, which occurs much more frequently in female than male athletes, often without contact. ACL injuries commonly occur during deceleration, landing, or cutting -- particularly if the athlete is off balance, with her feet flat and knees straight. Women's predisposition to this injury is related to both modifiable factors (environmental, biomechanical, and neuromuscular) and nonmodifiable ones (hormonal and anatomical). Overuse Injuries Overuse injuries result from three preventable factors: (1) training errors -- e.g., increasing workout duration or intensity too rapidly1; (2) gear problems -- e.g., mismatch of footwear to foot type; and …

Moderators of the relationship between exercise and mood changes: gender, exertion level, and workout duration

Although the role of exercise in improving mood is well established, less is known about moderators of this effect, particularly outside of the laboratory. The current study examined the effect of gender, type of exercise, level of exertion, and duration of workout on the exercise–mood relationship in a naturalistic setting. One hundred and thirty five participants (64 females) either engaged in weight training (n = 52) or cardiovascular (n = 83) exercise. Pre- and post-exercise assessments of mood were collected and changes in two types of mood, negative mood and exhaustion, were examined. Overall, participants reported improved mood after exercise in both domains. Workout duration and level of exertion significantly moderated the relationship of exercise to mood improvement (i.e., an increase in either corresponded to greater improved mood, ps<0.05). Overall, women showed more improved mood than men in the domain of exhaustion (p = 0.001).

THE EFFECT OF RESISTANCE TRAINING WITH DIFFERENT WORKOUT FREQUENCY ON STRENGTH AND LEAN TISSUE MASS

Changes in muscle mass and strength will vary depending on the frequency of training, duration of workouts, exercise intensity, and recovery between subsequent workouts. PURPOSE The purpose of this study was to determine the effect of resistance training with different workout frequency on muscle strength (I-RM) and lean tissue mass. METHODS Twenty-nine untrained volunteers (27–58 yr: 23 female and 6 male) were randomly assigned to one of two groups in blocks based on gender. All subjects performed the same nine whole body resistance training exercises at each training session using free weights and pulley machines for 6 weeks. Subjects assigned to Group 1 (n = 15) trained 2x/wk and performed 3 sets of 10 repetitions for each of the 9 exercises, while subjects in Group 2 (n = 14) trained 3x/wk and performed 2 sets of 10 repetitions for each of the 9 exercises. The weight used for each exercise and session was self-selected and adjusted so that the required number of repetitions and sets could be completed. Training logs were kept for each subject and exercise session so that training volume could be calculated for each group. Before and after training. 1-RM bench press and leg press, and lean tissue mass (DXA) were measured. RESULTS Both groups increased 1-RM bench press strength (20–25%), 1-RM leg press strength (17–41%) and lean tissue mass (2.0–2.5%) with training (P < 0.05), with a trend for greater gains in 1-RM leg press in Group 2 (P= 0.056). Calculation of training volume indicated a higher total volume for Group 2, but this was not significant (P= 0.09). CONCLUSION These results indicate that a resistance training program involving two workout sessions per week was as effective as the same program performed three times per week when the same number of total repetitions and exercises were performed by beginner weightlifters. However, there was a trend towards greater improvements in 1-RM leg strength and training volume with three workout sessions per week.