Associations of maximal strength and muscular endurance test scores with cardiorespiratory fitness and body composition

Distinct adaptations of muscle endurance but not strength or hypertrophy to low-load resistance training with and without blood flow restriction

Low-load resistance training promotes muscle strength and hypertrophic adaptations when combined with blood flow restriction (BFR). However, the effect of BFR on muscle endurance remains unclear. The aim of this study was to clarify the effects of BFR on muscle performance and adaptation, with special reference to local muscle endurance. In experiment 1, eight healthy men performed unilateral elbow flexion exercise to failure at 30% of one-repetition maximum with BFR (at 40% of estimated arterial occlusion pressure) and free blood flow (FBF). During the exercise, muscle activity and tissue oxygenation were measured from the biceps brachii. In experiment 2, another eight healthy men completed 6 weeks of elbow flexion training with BFR and FBF. The number of repetitions to failure at submaximal load (Rmax), the estimated time for peak torque output to decay by 50% during repetitive maximum voluntary contractions (half-time), one-repetition maximum, isometric strength and muscle thickness of elbow flexors were measured pre- and post-training. Blood flow restriction resulted in fewer repetitions and lower muscle tissue oxygenation at the end of exercise than FBF, while the muscle activity increased similarly to repetition failure. Blood flow restriction also resulted in a smaller post-training Rmax, which was strongly correlated with the total exercise volume over the 6 week period. Despite the smaller exercise volume, BFR resulted in similar improvements in half-time, muscle strength and thickness compared with FBF. These results suggest that the application of BFR can attenuate muscle endurance adaptations to low-load resistance training by decreasing the number of repetitions during exercise, both acutely and chronically.

Does Aerobic Exercise Increase Skeletal Muscle Mass in Female and Male Adults?

INTRODUCTION

It is uncertain whether aerobic exercise in the form of walking contributes to the preservation or increase in total or regional skeletal muscle mass (SMM).

PURPOSE

This study aimed to determine the effects of aerobic exercise on total and regional (upper body verses leg SMM) in male ( n = 105) and female ( n = 133) adults with overweight and obesity.

METHODS

A retrospective analysis of data from four randomized controlled trials. Participants included those who completed the given trial (control, n = 63; intervention, n = 175) and with complete magnetic resonance imaging (MRI) measured adipose tissue and SMM pre- and postintervention. Macronutrient intake was assessed for a subsample of participants. Supervised exercise was performed by walking on a treadmill for durations ranging from 12 to 24 wk at intensities between 50% and 75% of V̇O 2peak .

RESULTS

All MRI-measured adipose tissue depots were reduced, and cardiorespiratory fitness was increased by aerobic exercise compared with controls ( P < 0.001). Independent of baseline SMM, aerobic exercise was associated with a small reduction (estimated mean difference ± standard error) in whole-body SMM (-0.310 ± 0.150 kg, P = 0.039) and upper body SMM (-0.273 ± 0.121 kg, P = 0.025) compared with control. No between-group difference was observed for change in leg SMM ( P > 0.10). A negative association was observed between the relative change in body weight and change in total ( R2 = 0.37, P < 0.001), upper body ( R2 = 0.21, P < 0.001), and leg SMM ( R2 = 0.09, P = 0.701). The SMM-to-adipose tissue ratio increased in response to aerobic exercise and was positively associated with weight loss ( P < 0.001). Change in SMM was not associated with dietary protein intake ( P > 0.10).

CONCLUSIONS

Aerobic exercise performed while walking preserves, but does not increase, SMM in exercising muscle of adults. SMM not directly targeted by aerobic exercise may not be maintained.

Association of Strength Performance in Bench Press and Squat with Anthropometric Variables between Resistance-Trained Males and Females

Individual differences in the appropriate percentage of 1-RM for a given repetition range could be a result of variation in anthropometrics and/or sex. Strength endurance is the term used to describe the ability to perform a number of repetitions prior to failure (AMRAP) in sub-maximal lifts and is important in determining the appropriate load for the targeted repetition range. Earlier research investigating the association of AMRAP performance and anthropometric variables was often performed in a sample of pooled sexes or one sex only or by utilizing tests with low ecological validity. As such, this randomized cross-over study investigates the association of anthropometrics with different measures of strength (maximal and relative strength and AMRAP) in the squat and bench press for resistance-trained males (n = 19, 24.3 ± 3.5 years, 182 ± 7.3 cm, 87.1 ± 13.3 kg) and females (n = 17, 22.1 ± 3 years, 166.1 ± 3.7 cm, 65.5 ± 5.6 kg) and whether the association differs between the sexes. Participants were tested for 1-RM strength and AMRAP performance, with 60% of 1-RM in the squat and bench press. Correlational analysis revealed that for all participants, lean mass and body height were associated with 1-RM strength in the squat and bench press (0.66, p ≤ 0.01), while body height was inversely associated with AMRAP performance (r ≤ -0.36, p ≤ 0.02). Females had lower maximal and relative strength with a greater AMRAP performance. In the AMRAP squat, thigh length was inversely associated with performance in males, while fat percentage was inversely associated with performance in females. It was concluded that associations between strength performance and anthropometric variables differed for males and females in fat percentage, lean mass, and thigh length.

Military Body Composition Standards and Physical Performance: Historical Perspectives and Future Directions

ABSTRACT

Harty, PS, Friedl, KE, Nindl, BC, Harry, JR, Vellers, HL, and Tinsley, GM. Military body composition standards and physical performance: historical perspectives and future directions. J Strength Cond Res 36(12): 3551-3561, 2022-US military physique and body composition standards have been formally used for more than 100 years. These metrics promote appropriate physical fitness, trim appearance, and long-term health habits in soldiers, although many specific aspects of these standards have evolved as evidence-based changes have emerged. Body composition variables have been shown to be related to many physical performance outcomes including aerobic capacity, muscular endurance, strength and power production, and specialized occupational tasks involving heavy lifting and load carriage. Although all these attributes are relevant, individuals seeking to improve military performance should consider emphasizing strength, hypertrophy, and power production as primary training goals, as these traits appear vital to success in the new Army Combat Fitness Test introduced in 2020. This fundamental change in physical training may require an adjustment in body composition standards and methods of measurement as physique changes in modern male and female soldiers. Current research in the field of digital anthropometry (i.e., 3-D body scanning) has the potential to dramatically improve performance prediction algorithms and potentially could be used to inform training interventions. Similarly, height-adjusted body composition metrics such as fat-free mass index might serve to identify normal weight personnel with inadequate muscle mass, allowing for effective targeted nutritional and training interventions. This review provides an overview of the origin and evolution of current US military body composition standards in relation to military physical readiness, summarizes current evidence relating body composition parameters to aspects of physical performance, and discusses issues relevant to the emerging modern male and female warrior.

Body composition and grip strength constraints in elite male rink-hockey players of contrasting ethnicity

Rink hockey is a highly specialized and physiological demanding sport with sparse research regarding the game and athletes’ characteristics. A cross-sectional study was developed to characterize the body composition and grip strength of elite male rink hockey players and to establish the relationship between ethnicity on body composition and grip strength. A sample of 100 elite rink-hockey athletes aged 26.59 ± 6.02 participated in the study, comprised of 69 Caucasian male adults aged 27.58 ± 6.44 years and 31 Black African male adults aged 24.39 ± 4.27. Body composition was assessed by anthropometric measurements. Static grip strength was assessed with an adjustable dynamometer. Multiple regression analysis was applied to understand which variables constraints body fat percentage (BF) and grip strength. Body mass showed an average of 76.36 ± 9.18 kg for 175.80 ± 5.87 cm of height and BF% of 10.82 ± 5.07%. Maximal right grip strength was 50.91 ± 6.26 kg and 50.27 ± 6.23 kg for left grip strength. Four predictors accounted for 70.01% of the variance of BF%: abdominal circumference (p < 0.001), right thigh circumference (p < 0.001), right calf circumference (p = 0.001) and ethnicity (p = 0.016). Three predictors accounted for 13.1% of the variance of right grip strength: ethnicity (p = 0.013), chronological age (p = 0.024) and right distal thigh circumference (p = 0.014). Results suggest that elite rink hockey athletes have a specific anthropometric identity, which at the elite level may lead to reduced body fat and greater handgrip strength. Ethnicity seems to predict body fat and grip strength in elite rink hockey athletes.

Health and fitness data for police officers within a health and wellness program: Implications for occupational performance and career longevity

BACKGROUND: Health and wellness programs can be implemented at police departments. Little research has detailed the characteristics of officers within these programs. OBJECTIVE: To analyse the health and fitness data of officers involved in a health and wellness program from 2018–2020, and to profile the officers involved relative to population norms. METHODS: Analysis was conducted on archival data from 633 officers (523 males, 110 females) who participated in a health and wellness program from a large city police department. Data included: body mass; body fat percentage; blood pressure (BP); estimated maximal aerobic capacity; sit-and-reach; push-ups; vertical jump; grip strength; sit-ups; bench press ratio. Data were grouped by year (2018, 2019, 2020), and a univariate ANCOVA with Bonferroni post hoc adjustment determined any significant between-group differences. Individual officer data were also compared to population norms. RESULTS: The 2020 group had higher systolic BP compared to both other groups, and superior sit-and-reach and grip strength compared to the 2018 group (p <  0.05). Compared to population norms across the 3 years, 74–86% of officers had BP elevated above normal levels. Depending on the fitness component measured most officers (69–98%) were categorised as average or better. CONCLUSIONS: There were few differences between the year groups, although the 2020 officers did have superior sit-and-reach and grip strength. The higher systolic BP from the 2020 group may be indicative of the challenges of the year (pandemic, civil unrest). Officers generally had good profiles relative to population norms. The wellness program appeared to benefit the well-being of officers.

Fit (and Healthy) for Duty: Blood Lipid Profiles and Physical Fitness Test Relationships from Police Officers in a Health and Wellness Program

This research analyzed archival health and wellness program data (2018: 169 males, 39 females; 2019: 194 males, 43 females) to document police officer lipid profiles, and correlate lipids with fitness. Bloodwork included total cholesterol (TC), low-density lipoproteins (LDL-C), high-density lipoproteins (HDL-C), and triglycerides (TG). Fitness data included maximal aerobic capacity (V·O2max); sit-and-reach; push-ups; vertical jump; grip strength; sit-ups; and relative bench press (RBP). Lipid profiles were compared to national standards. Spearman’s correlations derived relationships between lipids and fitness (p < 0.05). Over 2018−2019, 68−76% of officers had desirable TC (<200 mg/dL) and HDL-C (≥60 mg/dL); 67−72% had desirable TG (<150 mg/dL). 54−62% of officers had LDL-C above desirable (≥100 mg/dL); 13−14% had mildly high TG (150−199 mg/dL); 16−18% had high TG (200−499 mg/dL). In 2018, HDL-C correlated with V·O2max, push-ups, grip strength, and RBP in males, and sit-ups in females. TG correlated with V·O2max (both sexes), sit-ups (males), and grip strength (females). In 2019, TG related to V·O2max, push-ups, vertical jump, sit-ups, and RBP in males. TG and LDL-C related to push-ups, and HDL-C to sit-ups and RBP in females. Relationship strengths were trivial-to-small (ρ = ±0.157 − 0.389). Most officers had good lipid profiles relative to cardiovascular disease risk. Nonetheless, the data highlighted the need for comprehensive approaches to decreasing risk.

Combined Eccentric-Isokinetic and Isoinertial Training Leads to Large Ring-Specific Strength Gains in Elite Gymnasts

In male elite gymnastics, lately, eccentric training is often used to improve the maximum specific strength of static elements on rings. Therefore, in this study, we aimed to investigate the effects of a three-week, gymnastic-specific, eccentric-isokinetic (0.1 m/s) cluster training with a change of stimulus after three of six training sessions (eccentric-isokinetic with additional load) on a computer-controlled training device on the improvement of the elements swallow and support scale on rings. Maximum strength and strength endurance in maintaining the static positions of ten international elite male gymnasts were determined on a weekly basis. After three weeks of training, specific maximum strength and strength endurance increased significantly (strength: swallow: +8.72%, p < 0.001; support scale: 8.32%, p < 0.0001; strength endurance: swallow: +122.36%; p = 0.02; Support Scale: +93.30%; p = 0.03). Consequently, top gymnasts can considerably improve ring-specific strength and strength endurance in only three weeks. The separate analysis of the effects of both eccentric-isokinetic training modalities showed that efficiency might even be increased in future training interventions. We suggest using this type of training in phases in which the technical training load is low and monitoring the adaptations in order to compile an individually optimized training after an intervention.

Sex Moderated Mediation of the Musculoskeletal Fitness in Relationship between High-Intensive Interval Training Performing during Physical Education Classes and Cardiorespiratory Fitness in Healthy Boys and Girls

High-intensive interval training (HIIT) is indicated as a means of improving cardiorespiratory fitness (CRF) and musculoskeletal fitness (MSF). The relationship between CRF and MSF was examined too. Little is known about gaining CRF from HIIT independence of MSF in adolescents. Therefore, this study is aimed at investigating whether MSF mediated the relationship between HIIT and CRF and whether sex moderate this relation. The study sample included 122 individuals (45 boys, 77 girls) 16.12 ± 0.38 years of secondary school age. Participants were assigned to the HIIT intervention or control groups. The intervention lasted 14 minutes during one physical education lesson per week for ten weeks. Outcome and potential mediator were residual changes calculated from pre- and postintervention results of MSF components: handgrip (HG), sit-ups (ABS), sit-and-reach (FL), vertical jump (VJ), and Harvard step-test representing cardiorespiratory fitness (CRF). MSF index (MSFI) was calculated as a construct, agglomerating all MSF, and tested its usefulness. HIIT significantly impacted CRF in boys and girls (B = 2.32, p = 0.032; B = 2.28, p = 0.005, respectively). The impact of the HIIT program on the ABS and FL was observed only in girls. The moderation effect of sex was confirmed. Significant effect of HIIT on CRF decreased (B_direct < B_total) and was no significant after including FL (B = 1.46, p = 0.62)—complete mediation, but no ABS (B = 2.97, p = 0.001)—partial mediation. CRF was mediated by changes in ABS (B = 2.28, p < 0.001) and FL (4.18, p < 0.001). MSFI was not mediating; its usefulness was limited. HIIT is an effective tool in the development of CRF in both sexes. MSF played a limited role in the relationship between HIIT and CRF. It suggested different mechanisms in both sexes: girls who performed better to the HIIT had better values of FL and ABS, but not boys. HIIT intervention involved modifications in ABS or FL, which also influenced the increase of CRF.

How Does Time Spent Working in Custody Influence Health and Fitness Characteristics of Law Enforcement Officers?

This study investigated the influence of time spent working in custody on the health and fitness of law enforcement officers (LEOs). Retrospective analysis was conducted on data from 48 male and 12 female LEOs, divided into groups based upon time spent working custody: LEO ≤ 24 (≤24 months; n = 15); LEO 2547 (25-47 months; n = 24); and LEO 48+ (≥48 months; n = 21). The following were measured: body mass index (BMI); fat mass percentage; waist-to-hip ratio (WHR); resting heart rate (RHR); blood pressure; grip strength; sit-and-reach; push-ups; sit-ups; and YMCA step test recovery heart rate (HR). A univariate ANCOVA (controlling for sex and age) with Bonferroni post hoc determined significant between-group differences. Select assessments were compared to normative data. The LEO 48+ group completed fewer sit-ups than the LEO 2547 group (p = 0.006); there were no other significant between-group differences. Forty-nine LEOs were overweight or obese according to BMI; 52 were fatter than average or above; 27 had a WHR that increased cardiovascular disease risk. Forty-three LEOs had very poor RHR; 52 had elevated blood pressure. Forty-eight LEOs had average-to-very poor step test recovery HR. Irrespective of time spent working in custody, personnel should be physically active to maintain health and fitness and, where possible, engage in formal strength training and conditioning.

Local Muscle Endurance and Strength Had Strong Relationship with CrossFit® Open 2020 in Amateur Athletes

This study analyzed the relationship between anthropometric measures, cardiorespiratory capacity, strength, power, and local muscle endurance with performance in the CrossFit^® Open 2020. For this, 17 volunteers (6 women) (29.0 ± 7.2 years) completed, on separate weeks, tests for body composition (dual-energy X-ray absorptiometry), maximal oxygen consumption (2 km row test), muscle strength (one repetition maximum (1 RM) back and front squat, isometric peak torque), muscle power (1 RM snatch and clean and jerk) and muscle endurance (Tibana test), which were compared with performance during the CrossFit^® Open 2020. Specific tests of localized muscular endurance and muscle strength had the strongest relationship with performance in the CrossFit^® Open 2020. On the other hand, the percentage of fat and cardiorespiratory capacity were not significantly correlated with CrossFit^® Open 2020 workout performance. Coaches and practitioners should therefore utilize these findings to assess physical fitness and organize the distribution of the training session based on less developed physical needs, in order to ensure an appropriate physiological adaptation for a given competition.

Differential Effects of Resistance- and Endurance-Based Exercise Programs on Muscular Fitness, Body Composition, and Cardiovascular Variables in Young Adult Women: Contextualizing the Efficacy of Self-Selected Exercise Modalities

There is an evident lack of research simultaneously investigating endurance training (ET) and resistance training (RT) with regard to their potential influence on fitness and health status in young women. This study aimed to determine the effects of RT and ET three times a week over an eight-week period on anthropometric/body composition indices, blood pressure (BP), and muscular fitness in apparently healthy young women who participated in a self-preferred program. The sample of participants comprised 57 young healthy women (23.9 ± 3.08 years, 165.5 ± 5.8 cm, 66.8 ± 7.2 kg) divided into ET (n = 18), RT (n = 19), and non-exercising (C) (n = 20) groups. The variables consisted of anthropometric/body composition indices (body mass, BMI, body fat, and lean body mass), muscular fitness variables (lower body strength, upper body strength, abdominal strength, dynamometric force, and flexibility), and cardiovascular parameters (resting heart rate and systolic and diastolic BP). A pre- and post-testing design, with factorial analysis of variance for repeated measurements (ANOVA: Group × Measurement), including a consecutive post hoc test, was applied. The ANOVA indicated a similar improvement in body composition (increase in lean body mass and decrease in body fat percentage), resting heart rate, and flexibility in both of the exercise groups, with no significant changes in the C group. RT improved the participants' strength and force capacities to a greater extent than ET. BP showed a trend of improvement in both of the training groups, but without statistically significant pre- to post-changes. Correlation analysis calculated with variables of pre- to post-differences (VDs) indicated poor associations between VDs, indicating relative independence of the obtained effects for the different variables in each training group. Although this investigation comprised apparently healthy young women, numerous positive changes indicated the efficacy of both programs in a relatively short period of time. While the participants in this study self-selected training programs, the evidenced positive effects can be at least partially related to this fact.

The Relationship Habits of Through Breakfast and Physical Activity with Abdominal Obesity in Nutrition Students

Background : Abdominal obesity is obesity characterized by the accumulation of excess fat in the abdominal area. The risk of metabolic and cardiovascular disease may increase due to abdominal obesity. One of the factors associated with abdominal obesity is imbalance between energy intake and physical activity. Several studies have stated that skipping breakfast is associated with an increased risk of obesity with the tendency to consume high calorie foods to provide energy for activities.Objectives : The purpose of this study is to analyze the relationship between skipping breakfast, level of physical activity and obesity in nutrition students at Public Health Faculty, Airlangga University.Methods : This research is observational analytic with cross sectional design. The population in this study were nutrition students at Public Health Faculty, Airlangga University. The number of samples was 60 people which selected by proportional random sampling method. Data were collected include the measurements of waist circumference, interviews using respondent's identity questionnaire and physical activity recall 3 x 24 hours. Data were analyze with Spearman correlation test.Results : Based on the results, it was found that 33.3% of the respondents were obese. The results of statistical tests shows a negative correlation between skipping breakfast and abdominal obesity (p = 0.000). The results of this study also showed that there is no significant correlation between the level of physical activity and obesity (p = 0.618).Conclusions : Skipping breakfast was significantly associated with abdominal obesity in the young adult students group. Therefore, it is better if the habits of skipping breakfast can be replaced with breakfast habits to prevent abdominal obesity. 

Intensive Sports Nutrition Program Improving Body Composition and Energy Intake among Elite Combat Sport Athletes

ABSTRAK Latar Belakang :Gizi olahraga merupakan aspek penting dalam mengatur asupan makanan dan komposisi tubuh untuk mencapai performa yang optimal. Studi epidemiologis menunjukkan sebagian besar asupan atlet tidak adekuat dan dapat mempengaruhi komposisi tubuh yang ideal.Tujuan :Tujuan dari penelitian ini adalah untuk menganalisis pengaruh pendampingan gizi olahraga terhadap komposisi tubuh dan asupan energi atlet bela diri.Metode :Pendampingan gizi intensif dilakukan selama empat bulan (Juni- September 2019). Pengukuran komposisi tubuh  dilakukan 2 kali, yakni sebelum dan sesudah intervensi dengan menganalisis hasil pengukuran dari alat BIA (Bio Impadance Analyzer) tipe MBCA (Medical Body Compotiton Analyzer) 515/514 merk seca©. Variabel yang dianalisis diantaranya, total asupan kalori sehari diukur menggunakan instrumen Recall-24 jam, komposisi tubuh diukur dengan alat BIA yakni Fat Mass (FM), Fat Free Mass (FFM) dan Skeletal Muscle Mass (SMM). Pendampingan gizi dilakukan oleh ahli gizi olahraga yang mengunjungi 24 responden setiap bulan dan memberikan materi pendidikan gizi, memberikan makanan sehat dan memberikan konseling permasalahan gizi atlet.Hasil : Hasil penelitian ini menunjukkan adanya peningkatan secara signifikan pada asupan energi total (1496,2±654,4 menjadi 1688,5±679,8, p= 0,002). Pada komposisi tubuh terjadi peningkatan pada FFM dan SMM yakni (56,57 ± 9,91 kg vs 57,01 ± 9,53, p = 0,032) dan (27,49 ± 5,58 vs 27,75 ± 5,31, p = 0,005) dan tidak ada perbedaan signifikan dalam variabel  FM.Kesimpulan : Kesimpulan dari percobaan ini adalah pendampingan gizi secara intensif dapat meningkatkan asupan energi total, FFM dan SMM pada atlet bela diri. Kata Kunci : Komposisi tubuh, pendampingan gizi, asupan energiABSTRACTBackground :Sports nutrition is very urgent to improve nutrition knowledge, dietary intake and body composition to achieve an optimum athletic performance. Epidemiological studies showed most athletes lack of getting adequate intake and maintaining an ideal body composition.Objective :This study aims to analyze the effect of sport nutrition education on body composition and energy intake among elite combat sport athletes.Methods :Intensive sport nutrition was conducted for four months June until September 2019. Body composition was assessed  for 2 times, before and after intervention using bioelectric impedance analysis (BIA), with seca© brand 515/514 type of stainless steel electrodes.Measurement of energy intake with recall 24 hours before and after the intervention. The variables studied were Fat Mass (FM), Fat Free Mass (FFM), Skeletal Muscle Mass (SMM) and energy intake.The professional sport nutritionist and dietitians visited 24 subjects every month by teaching nutrition education, bringing the healthy food, and facilitating the counseling about sport nutrition.Result :Energy intake increased significantly (1496,2±654,4 to 1688,5±679,8, p= 0,002). FFM and SMM increased significantly pre to post (56.57±9.91 kg vs 57.01±9.53, p=0.032) and (27.49±5.58 vs 27.75±5.31, p=0.005) respectively, meanwhile no significant differences in FM variable.Conclusion : Our findings indicate that intensive sport nutritionimproved energy intake, FFM and SMM among elite combat sport athletes. Keywords : Body compotition, sport nutririon education, energy intake

Development of a Body Mass Index-based Body Fat Equation: Effect of Handgrip Strength

Body mass index (BMI)-based body fat equations from Womersley (BMIWOMERSLEY), Jackson (BMIJACKSON), Deurenberg (BMIDEURENBERG), and Gallagher (BMIGALLAGHER) are practical in clinical and field settings. However, research has shown these prediction equations produce large error, which may be due to the inability of BMI to account for differences in fat mass and fat-free mass. Thus, accounting for variations in muscular strength via relative handgrip (RHG) strength could help enhance the accuracy of a BMI-based body fat equation.

PURPOSE

The purpose of the current study was twofold: 1) to develop a new BMI-based body fat equation that includes the measurement of RHG (BMINICKERSON) and 2) to cross-validate BMINICKERSON, BMIWOMERSLEY, BMIJACKSON, BMIDEURENBERG, and BMIGALLAGHER against a four-compartment criterion.

METHODS

The development and cross-validation samples consisted of 230 and 110 participants, respectively. Criterion body fat percent was determined with a four-compartment model. RHG was calculated by summing the max of each handgrip strength measurement and dividing by body mass. BMI (kg·m), RHG (kg·kg), age (yr), ethnicity (Hispanic or non-Hispanic White), and sex (male or female) were entered into a stepwise regression to calculate BMINICKERSON.

RESULTS

BMINICKERSON was calculated as follows: body fat percent = 21.504 - (12.484 × RHG) - (7.998 × sex) + (0.722 × BMI). In the cross-validation sample, BMINICKERSON produced lower constant error (CE) and total error (TE) values (CE = -0.11%, TE = 4.28%) than all other BMI-based body fat equations (CE = 0.89%-1.90%, TE = 5.71%-6.87%). Furthermore, the 95% limits of agreement were lower for BMINICKERSON ± 8.47% than previous BMI-based body fat equations (95% limits of agreement = ±11.14% to 13.33%).

CONCLUSION

Current study results confirm that previous BMI-based body fat equations produce large error in Hispanics and non-Hispanic Whites but can be improved by accounting for RHG. Allied health professionals are encouraged to use BMINICKERSON in clinical and field settings for adiposity assessments.

Upper body strength endurance evaluation: A comparison between the handgrip strength and three body weight tests

BACKGROUND: The hand-grip strength test has been widely adopted to evaluate upper limb strength. Other field based tests as push-ups and pull-ups are commonly used for the same purpose. It is however unclear if these may be used interchangeably for upper body strength evaluation. OBJECTIVE: The purpose of this investigation was to evaluate strength endurance of the upper body and understand which test could be the most appropriate for upper body evaluation. METHODS: Thirty-eight healthy young male participants were tested with three tests comprised of: 1) push-ups (PS), 2) pull-ups (PL) and 3) parallel dips (PD) performed to exhaustion. Grip strength (GS), total number of repetitions, time-to-complete the test, repetition cadence and rate of perceived exertion (RPE) were also retrieved for investigation. RESULTS: Repetitions, time-to-complete the test and repetition cadence significantly differed across the three tests (p< 0.001). No difference in the RPE was present. No correlation was present between GS and the other tests. No correlation was present between RPE and performance values and time-to-complete the tests. BMI was positively correlated to RPE in all tests. All tests strongly correlate to each other (PS vs. PL r= 0.55; PS vs. PD r= 0.64; PL vs. PD r= 0.70) and to time-to-complete the test (PS r= 0.79; PL r= 0.69; PD r= 0.66). Only the results of the PD correlate to their respective repetition cadence (r= 0.66). CONCLUSIONS: GS is not suitable to evaluate strength endurance. PS, PL and PD are all suitable to evaluate strength endurance. However, PD may be preferred to evaluate the upper body, if velocity also needs to be taken into account.

The Relationship between Body Mass Index, Body Fat Percentage, and Dietary Intake with Muscle Fatigue in Adolescent Football Players

It is important for football players to maintain muscle strength through the entire match. The aim of this study was to investigate body mass index (BMI), body fat percentage (BF%), dietary intake (energy, carbohydrate, and protein) and its relationship with muscle fatigue among adolescent football players. This was a cross-sectional study involving 26 football players aged 15-17 y. BMI was determined using WHO Anhtro Plus, BF% was analyzed using Bioelectrical Impedance Analysis (BIA) and categorized using bodyfat curves for children, and dietary intake was assessed using 3×24 h dietary recall. Running-Based Anaerobic Sprint Test (RAST) was conducted twice and averaged to identify muscle fatigue. Pearson correlation and multiple-regression analysis were performed to determine the relationship between variables. The results showed that overall participants had healthy weight (17.61±1.82 kg/m2), good diet pattern (energy 99.08±14.34%, carbohydrate 92.88±9.54% and protein 95.96±23.41%), but low body fat (6.76±2.12%). In pearson test, negative correlations were found in muscle fatigue and BMI (r=-0.393, p=0.047), as well as BF% (r=-0.458, p=0.019), but positive between muscle fatigue and energy intake (r=0.538, p=0.005). Furthermore, multiple-regression analysis only confirmed statistically significant relationship between energy intake and muscle fatigue (p=0.028). We conclude that the higher BMI and BF% may lead to greater muscle fatigue, while higher energy intake has significant improvement to reduce muscle fatigue. Hence, it is essential for football players to consume adequate energy, and consider to maintain BMI and BF% at optimal range.

Muscular strength and cardiovascular risk factors in adults: a systematic review

OBJECTIVE

The purpose of this study was to identify and summarize the relationships between MS and individual components of metabolic syndrome (MetS) [high waist circumference (WC), high blood pressure (BP), high systolic blood pressure (SBP), high diastolic blood pressure (DBP), high triglycerides (TG), fasting blood glucose (GL) and low HDL cholesterol levels (HDL-C)] in adults.

METHODS

A systematic review was performed on six electronic databases (Lilacs, Pubmed, Scielo, Scopus, Sportdiscus, and Web of Knowledge), with complimentary searches in reference lists. The databases were investigated without restrictions regarding the period of publication.

RESULTS

Of the 6,833 articles initially identified, 17 were included, with data on 43,343 adults. Higher MS values were associated with lower WC values. Different results in relation to the association between MS and BP, MS and SBP, and MS and DBP were verified. In addition, inconclusive results were verified in the relationship between MS and TG, MS and HDL-C, and MS and GL.

CONCLUSION

Higher MS values were related with lower WC in adults. More evidence from longitudinal studies with high methodological rigor is needed to elucidate the relationship between MS and CVD among adults.

Association of mitochondrial DNA haplogroups J and K with low response in exercise training among Finnish military conscripts

Background

We have previously suggested that some of the mutations defining mitochondrial DNA (mtDNA) haplogroups J and K produce an uncoupling effect on oxidative phosphorylation and thus are detrimental for elite endurance performance. Here, the association between haplogroups J and K and physical performance was determined in a population-based cohort of 1036 Finnish military conscripts.

Results

Following a standard-dose training period, excellence in endurance performance was less frequent among subjects with haplogroups J or K than among subjects with non-JK haplogroups (p = 0.041), and this finding was more apparent among the best-performing subjects (p < 0.001).

Conclusions

These results suggest that mtDNA haplogroups are one of the genetic determinants explaining individual variability in the adaptive response to endurance training, and mtDNA haplogroups J and K are markers of low-responders in exercise training.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07383-x.

Relative Weights of Physical Strength Factors in Sports Events: Focused on Similarity Sports Events Group According to the Sports Physiological View

The purpose of this study was to investigate the relative weights of physical strength factors in sports events. We selected 16,645 people as a sample group who participated in physical fitness measurements through eight sports science centers across the country from 2016 until August of 2018, and divided into four sports types depending on the sports physiological view: type A: short-term muscular power and short-term muscular endurance, type B: mid-term muscular power, type C: long-term cardiorespiratory endurance, type D: coordination capability (CC), agility, flexibility, and balance. Categorized the performance level into excellent athletes and non-excellent athletes, and standardized (T-score) the measured value after considering sex, age and sports type group. Used logistic regression analysis for the method of analysis, and calculated the relative weights of physical strength factor with different sports by using Wald value which was calculated from logistic regression analysis. As a result, the relative weights of physical factor in type A were power 30%, muscular power (MP) 18%, CC 16%, agility 11%, flexibility 10%, cardiorespiratory endurance (CE) 1%, and balance 0%. The relative weights of physical factor in type B were muscular endurance (ME) 43%, MP 25%, power 20%, balance 9%, CE 2%, flexibility 1%, agility 0%, and CC 0%. The relative weights of physical factor in type C were ME 41%, CE 37%, power 10%, agility 8%, flexibility 2%, CC 2%, ME 0%, and balance 0%. Need more specific classification standard for type D sports. Hope the results of this study were used to measure physical fitness level and used as baseline data for recruiting future talents.

Maximum isometric tongue force in patients with obstructive sleep apnoea

Background

Obstructive sleep apnea (OSA) is a sleep disorder with a prevalence of 9–38%. The underlying pathology in OSA is a collapse of the upper airway. Especially in more severely affected patients, this collapse is often located at the level of the tongue base. Therefore, various implantable systems (anchors and ligament techniques) were developed to prevent or overcome this collapse. These systems are exposed to various forces. Different models have been developed to measure these forces and data comparing forces in healthy individuals with OSA patients are rare.

Purpose

Purpose of the study was to evaluate possible differences in tongue forces between healthy individuals and patients with OSA.

Method

To evaluate maximum isometric tongue forces, we conducted a matched pair design study including 20 healthy individuals and 20 patients suffering from OSA. Maximum isometric tongue forces were measured in an anterior/posterior direction with the help of self-designed new device that clamps the tongue.

Results

We could show that the maximum isometric force does not differ significantly in healthy individuals (10.7 ± 5.2N) from patients with OSA (14.4 ± 6.3N).

Conclusion

Currently there are no indications that maximum isometric tongue force does differ in healthy individuals and patients with OSA. Higher, as well as lower, tongue forces in patients with OSA seem not to differ from healthy subjects and therefore may not be needed to consider, in the development of tongue management devices, for OSA patients.

Recruit Fitness Standards From a Large Law Enforcement Agency: Between-Class Comparisons, Percentile Rankings, and Implications for Physical Training

Lockie, RG, Dawes, JJ, Orr, RM, and Dulla, JM. Recruit fitness standards from a large law enforcement agency: Between-class comparisons, percentile rankings, and implications for physical training. J Strength Cond Res 34(4): 934-941, 2020-Law enforcement can be a physically demanding profession. Many agencies use a "one-size-fits-all" academy training approach, which may not be optimal for all recruits. There is also little information that benchmarks fitness of law enforcement recruits. The purpose of this study was to analyze between-academy class differences in fitness, as well as produce normative data for the development of strength and conditioning programs. A retrospective analysis of 908 recruits (761 men and 147 women), comprising 11 classes from one agency, was used. Fitness assessment data included push-ups, sit-ups, and mountain climbers in 120 seconds; pull-ups; 201-m run; and 2.4-km run. A one-way analysis of variance with a Bonferroni post hoc adjustment revealed that fitness varied significantly between classes. Class 11 completed less sit-ups than 6 other classes (p ≤ 0.033) and were slower in the 201-m and 2.4-km run than 5 classes (p ≤ 0.005). Class 7 completed less push-ups than 3 classes (p ≤ 0.036) and less mountain climbers and were slower in the 201-m run than 5 classes (p ≤ 0.005). Individual recruit analysis and percentile data indicated a wide spread of all assessment results and the effects upon female recruits. For example, 81% of women completed ≤2 pull-ups and were in the bottom 2 percentile bands; 72-76% of women were in the bottom 3 bands for push-ups and the 201-m run. Fitness varies from class-to-class, and female recruits will generally be less physically fit. Training staff should ideally implement individualized, ability-based programming where appropriate to train their recruits.

The Association between Physical Fitness Performance and Abdominal Obesity Risk among Taiwanese Adults: A Cross-Sectional Study

The present study aims to investigate the associations between physical fitness performance and abdominal obesity risk among Taiwanese adults. We conducted a cross-sectional study and reviewed the data derived from the National Physical Fitness Survey in Taiwan (HPFSIT). Data from a total of 62,486 respondents aged 23–64 years were collected in this study. The participants completed a standardized structural questionnaire and a series of anthropometric characteristics (body mass index and waist-to-hip ratio) and physical fitness (3-min step tests, 1-min sit-up tests, and sit-and-reach tests) assessments. Waist circumference was used to define abdominal obesity status. A multiple logistic regression analysis was conducted. Our results presented almost entirely significant associations (except for women) on the 3-min step test. Moreover, the results suggest that muscular strength, endurance, and flexibility may be effective predictors of abdominal obesity among men and women, whereas cardiorespiratory fitness predicted abdominal obesity only in men. According to the results of this study, the fitness–abdominal obesity associations are minor based on a mixed population analysis. However, dose–response relationships have been observed. The present study provides a new perspective by using different types of fitness performance to predict abdominal obesity.

Cardiorespiratory and muscular fitness in young adult Finnish men between 2003 and 2015

INTRODUCTION

Physical fitness is strongly related to health and may offer valuable information about public health. We investigated trends in physical fitness, leisure-time physical activity (LTPA), and anthropometry of young healthy adult Finnish men in representative population-based samples between 2003 and 2015.

METHODS

Three independent cross-sectional samples of 18- to 35-year-old Finnish men were assessed in 2003 (n = 889), 2008 (n = 803), and 2015 (n = 690). Cardiorespiratory (VO₂ max) and muscular fitness (1-minute sit-ups and push-ups), body mass, and height were measured. Self-reported LTPA was assessed.

RESULTS

After adjusting for age, education, and smoking, cardiorespiratory fitness was higher in 2003 (mean: 43.5, 95%CI: 42.9-44.1 mL/kg/min) compared to 2008 (41.3, 95%CI: 40.7-41.9 mL/kg/min) and 2015 (40.6, 95%CI: 40.0-41.2 mL/kg/min) (P < .001), whereas no difference was observed between 2008 and 2015. The lowest values in muscular fitness were observed in 2003, while no clear trends were further noticed. The adjusted BMI was higher in 2008 (25.1, 95%CI: 24.9-25.4) and 2015 (25.3, 95%CI: 25.3, 95%CI: 25.0-25.6) compared to 2003 (24.5, 95%CI: 24.3-24.8) (P < .005). In 2015, a higher proportion of individuals exercised at least four times per week compared to 2003 and 2008 (P < .05).

CONCLUSION

The decrease in cardiorespiratory fitness that took place between 2003 and 2008 plateaued after 2008. The plateau is in accordance with the previously observed trend of 5-10 years younger Finnish men. Moreover, muscular fitness was for the most part higher in 2008 and 2015 compared to 2003. Efforts directed to promote regular physical activity and improve physical fitness are needed.

Roar of a Champion: Loudness and Voice Pitch Predict Perceived Fighting Ability but Not Success in MMA Fighters

Historically, antagonistic interactions have been a crucial determinant of access to various fitness-affecting resources. In many vertebrate species, information about relative fighting ability is conveyed, among other things, by vocalization. Previous research found that men's upper-body strength can be assessed from voice. In the present study, we tested formidability perception of intimidating vocalization (roars) and a short utterance produced by amateur male MMA fighters attending the amateur European Championships in relation to their physical fitness indicators and fighting success. We also tested acoustic predictors of the perceived formidability. We found that body height, weight, and physical fitness failed to predict perceived formidability either from speech or from the roars. Similarly, there was no significant association between formidability of the roars and utterances and actual fighting success. Perceived formidability was predicted mainly by roars' and utterances' intensity and roars' harmonics-to-noise ratio and duration. Interestingly, fundamental frequency (F₀) predicted formidability ratings in both roars and utterances but in an opposite manner, so that low F₀ utterances but high F₀ roars were rated as more formidable. Our results suggest that formidability perception is primarily driven by intensity and duration of the vocalizations.

Predictors of Fighting Ability Inferences Based on Faces

Facial perception plays a key role in various social interactions, including formidability assessments. People make relatively accurate inferences about men's physical strength, aggressiveness, and success in physical confrontations based on facial cues. The physical factors related to the perception of fighting ability and their relative contribution have not been investigated yet, since most existing studies employed only a limited number of threat potential measures or proxies. In the present study, we collected data from Czech Mixed Martial Arts (MMA) fighters regarding their fighting success and physical performance in order to test physical predictors of perceived fighting ability made on the basis of high-fidelity facial photographs. We have also explored the relationship between perceived and actual fighting ability. We created standardized 360° photographs of 44 MMA fighters which were assessed on their perceived fighting ability by 94 raters (46 males). Further, we obtained data regarding their physical characteristics (e.g., age, height, body composition) and performance (MMA score, isometric strength, anaerobic performance, lung capacity). In contrast to previous studies, we did not find any significant links between the actual and the perceived fighting ability. The results of a multiple regression analysis have, however, shown that heavier fighters and those with higher anaerobic performance were judged as more successful. Our results suggest that certain physical performance-related characteristics are mirrored in individuals' faces but assessments of fighting success based on facial cues are not congruent with actual fighting performance.

Normal weight obesity and physical fitness in Chinese university students: an overlooked association

BACKGROUND

The primary aim of this study was to examine the associations of normal weight obesity (NWO) with physical fitness in Chinese university students. As a secondary aim, we assessed whether possible differences in physical fitness between students classified as NWO and normal weight non-obese (NWNO) were mediated by skeletal muscles mass.

METHODS

A total of 383 students (205 males and 178 females, aged 18-24 years) from two universities volunteered to participate in this study. Body height and weight were measured by standard procedures and body composition was assessed by bio-impedance analysis (InBody 720). NWO was defined by a BMI of 18.5-23.9 kg/m2 and a body fat percentage of > 20% or > 30% in male and female students, respectively. Physical fitness was measured using a 10-min intermittent endurance running test (Andersen test), countermovement jumps (CMJ) and a 5 × 5 m shuttle run test (5mSR). The level of leisure time physical activity (PA) was assessed by a questionnaire.

RESULTS

13.7% of male and 27.5% of female students were classified as NWO. Compared to NWNO, students classified as NWO showed a significantly poorer performance in the Andersen test (males: 1146 ± 70 m vs. 1046 ± 95 m, females: 968 ± 61 m vs. 907 ± 67 m, p < 0.001), CMJ (males: 55.0 ± 7.6 cm vs. 44.9 ± 7.5 cm, females: 39.8 ± 8.0 cm vs. 33.7 ± 5.9 cm, p < 0.001) and 5mSR (males: 18.7 ± 1.0 s vs. 20.0 ± 0.9 s, females: 21.1 ± 1.1 s vs. 22.4 ± 1.3 s, p < 0.001), respectively. The lower levels of physical fitness in NWO were partially explained by lower skeletal muscle mass (p < 0.001) both in male and female students.

CONCLUSIONS

NWO was associated with poorer physical fitness and the relationship was partially mediated by lower skeletal muscle mass. The study indicated that attention should be paid for the potential hidden health risk in university students with normal body mass index but excessive fat mass.

The association between obesity related health risk and fitness test results in the British Army personnel

OBJECTIVE

In the British Army, fitness is assessed by a load carriage test (Annual Fitness Test, AFT) and by a three event Personal Fitness Assessment (PFA). Body composition based on body mass index (BMI) and abdominal circumference (AC) is also part of a mandatory annual assessment. This study examined the influence of BMI and AC on fitness test results within a comprehensive sample of British Army personnel.

DESIGN

Secondary analyse were carried out on data obtained from the 2011 Defence Analytical Services and Advice (DASA) database for 50,635 soldiers (47,173 men and 3,462 women).

METHODS

Comparisons using loglinear analysis were made between groups of individuals classified by body mass index as obese (≥30kg/m2) and not obese (<30kg/m2), and further classified using combined BMI and AC for obesity-related health risks to compare "no risk" with "increased risk."

RESULTS

Not obese or "no risk" soldiers had a significant relationship with success in the AFT (p<0.01) and PFA (p<0.01). Of those soldiers who attempted the AFT, 99% of men and 92% of women passed; for the PFA, 92% of men and 91% of women passed. Obese or "at risk" soldiers were more likely to fail and far less likely to take both tests (p<0.05). Compared to older obese soldiers, young obese soldiers were more likely to attempt the tests.

CONCLUSIONS

We conclude that BMI and AC are useful indicators of fitness test outcome in the British Army.

The Relationship Between Hip Strength and the Y Balance Test

CONTEXT

The Y Balance Test was developed as a test of dynamic postural control and has been shown to be predictive of lower-extremity injury. However, the relationship between hip strength and performance on the Y Balance Test has not been fully elucidated.

OBJECTIVE

The goal of this study was to identify the relationship between components of isometric hip strength and the Y Balance Test, to provide clinicians better guidance as to specific areas of muscle performance to address in the event of poor performance on the Y Balance Test.

DESIGN

Laboratory study.

SETTING

Biomechanics laboratory.

PARTICIPANTS

A total of 73 healthy participants (40 males and 33 females) volunteered for this study.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Participants completed the Y Balance Test on the right leg. The authors then measured peak isometric torque in hip external rotation, abduction, and extension. Correlations were calculated between torque measurements, normalized for mass and Y Balance Test performance. Significant relationships were used in linear regression models to determine which variables were predictive of the Y Balance Test performance.

RESULTS

The authors found significant positive correlations between Y Balance Test performance and hip abduction strength. They also found correlations between the Y Balance Test and hip extension and external rotation strengths. Linear regression analysis showed hip abduction to be the only significant predictor of Y Balance performance.

CONCLUSIONS

The authors found the strongest association between the Y Balance Test and hip abduction strength. They also showed smaller but significant associations with hip extension and external rotation strength. When entered into a linear regression analysis, hip abduction strength was the only significant predictor of Y Balance performance. Using this information, practitioners should look to hip abduction strength when patients exhibit deficits in the Y Balance Test.

Relationship between velocity and muscular endurance of the upper body

Strength, power and muscular endurance tests have been developed as means of assessing people's physical abilities. However, testing may be expensive or time consuming. A method to reduce the time of physical assessment could be to use predictive algorithms for indirect assessment. The aim of this study will be to determine a relationship between strength, power and muscular endurance in order to identify predictors for an easier and faster assessment. 33 male strength-trained participants (22.8 ± 4.6 years, 172.5 ± 6.7 cm, 68.0 ± 10.6 kg) performed a single pull-up (SPU) and a single push-up (SPH) and a set of pull-ups (EPU) and push-ups (EPH) to exhaustion. The participants were divided into three sub-groups according to their training experience. Force(F), Power(P), Velocity(V) and relative power(R-P), extracted from an accelerometer (500 Hz), were compared between groups (ANOVA) and a subsequent linear regression analysis was performed to identify predictors of the performance measures. The regression models were able to explain 61% of the variance with the EPU as dependent variable and the V of the SPU as independent variable and 68% of the variance with the EPH as dependent variable and EPU as independent variable. In addition, increased performance measures were found according to training experience, in particular regarding muscular endurance of both the EPU and EPH (p < 0.001 and p < 0.01, respectively). A significant effect of training experience was also present for the V of the SPU (p < 0.001). The results indicate that a relation between muscular endurance and velocity is present. The generated equations allow to estimate both the number of EPH and EPU from a SPU. The equations may be helpful to reduce the time of assessment for upper body physical evaluation.

Associations of physical strength with facial shape in an African pastoralist society, the Maasai of Northern Tanzania

OBJECTIVES

Previous research has documented associations of physical strength and facial morphology predominantly in men of Western societies. Faces of strong men tend to be more robust, are rounder and have a prominent jawline compared with faces of weak men. Here, we investigate whether the morphometric patterns of strength-face relationships reported for members of industrialized societies can also be found in members of an African pastoralist society, the Maasai of Northern Tanzania.

MATERIALS AND METHODS

Handgrip strength (HGS) measures and facial photographs were collected from a sample of 185 men and 120 women of the Maasai in the Ngorongoro Conservation Area. In young-adults (20-29 years; n = 95) and mid-adults (30-50 years; n = 114), we digitized 71 somatometric landmarks and semilandmarks to capture variation in facial morphology and performed shape regressions of landmark coordinates upon HGS. Results were visualized in the form of thin-plate plate spline deformation grids and geometric morphometric morphs.

RESULTS

Individuals with higher HGS tended to have wider faces with a lower and broader forehead, a wider distance between the medial canthi of the eyes, a wider nose, fuller lips, and a larger, squarer lower facial outline compared with weaker individuals of the same age-sex group. In mid-adult men, these associations were weaker than in the other age-sex groups.

DISCUSSION

We conclude that the patterns of HGS relationships with face shape in the Maasai are similar to those reported from related investigations in samples of industrialized societies. We discuss differences between the present and related studies with regard to knowledge about the causes for age- and sex-related facial shape variation and physical strength associations.

Predictive factors of peak aerobic capacity using simple measurements of anthropometry and musculoskeletal fitness in paraplegic men

BACKGROUND

Protocols for evaluating cardiovascular fitness for wheelchair-dependent persons are still scarcely accessible due to the requirements such as specialized equipment and expertise in community or public healthcare settings. This study aimed to assess the potential of secondary utilization of musculoskeletal fitness components for estimating peak oxygen uptake (VO2peak) in paraplegic men.

METHODS

Thirty-three paraplegic men (T1-L3) aged 23-63 years underwent anthropometry (height, weight and calculated body mass index and body surface area) and upper-body musculoskeletal fitness tests (back-scratch, arm-curls and handgrip strength tests) and performed a graded exercise test with an arm-crank ergometer on two non-consecutive days. To determine the relationship between VO2peak and various kinanthropometric parameters and derive a regression model that predicts the VO2peak, uni- and multivariate analyses were conducted, respectively.

RESULTS

Maximal numbers of arm curls on either arm (r=0.486, P=0.004) and the back-scratch distance (r=0.426, P=0.013) were moderately correlated with VO2peak. Moreover, among the indices of handgrip strength, average handgrip strength of both hands divided by the body surface area showed a strong correlation coefficient with VO2peak (r=0.674, P<0.001). Multivariate linear regression analysis indicated that muscular endurance and strength were the main predictors for estimating VO2peak. Considering shoulder flexibility, age, and anthropometric variables, the regression model showed the highest adjusted R2 of 0.811 and lowest standard error of estimate of 3.54 mL·kg-1·min-1 (P<0.001). The Bland-Altman plots indicated good agreement between actual and estimated VO2peak. The mean absolute prediction error was 11.9%.

CONCLUSIONS

Musculoskeletal fitness and anthropometric components may be predictive factors of a new conceptual modality estimating concomitant cardiorespiratory fitness beyond their traditional health-related indications.

Cross-Cultural Investigation of Male Gait Perception in Relation to Physical Strength and Speed

Previous research documents that men and women can accurately judge male physical strength from gait, but also that the sexes differ in attractiveness judgments of strong and weak male walkers. Women's (but not men's) attractiveness assessments of strong male walkers are higher than for weak male walkers. Here, we extend this research to assessments of strong and weak male walkers in Chile, Germany, and Russia. Men and women judged videos of virtual characters, animated with the walk movements of motion-captured men, on strength and attractiveness. In two countries (Germany and Russia), these videos were additionally presented at 70% (slower) and 130% (faster) of their original speed. Stronger walkers were judged to be stronger and more attractive than weak walkers, and this effect was independent of country (but not sex). Women tended to provide higher attractiveness judgments to strong walkers, and men tended to provide higher attractiveness judgments to weak walkers. In addition, German and Russian participants rated strong walkers most attractive at slow and fast speed. Thus, across countries men and women can assess male strength from gait, although they tended to differ in attractiveness assessments of strong and weak male walkers. Attractiveness assessments of male gait may be influenced by society-specific emphasis on male physical strength.

Acute effects of Kinesio taping on muscle function and self-perceived fatigue level in healthy adults

This study investigated the acute effects of Kinesio taping (KT) on muscular power, strength, endurance, and self-perceived fatigue level. This is a randomized, partial double-blind, crossover trial. Eighteen healthy adults (7 males [23.86 ± 1.68 years] and 11 females [24.82 ± 3.71 years]) were enrolled in this study. All subjects underwent three different trials which included no tap (NT), placebo tap (PT), and KT. Idividuals were assessed for peak and mean power, muscular strength and endurance, and self-perceived fatigue after each condition. The results revealed no significant differences in all variables (p > 0.05) except muscular endurance (F = 5.775, p = 0.007). Muscular endurance in the NT (58.28 ± 12.18 reps/min) condition was significantly higher than that in the KT (52.83 ± 11.76 reps/min) condition. These results suggest that KT on rectus femoris and the patella of the lower limb does not improve muscular function and self-perceived fatigue level. KT is unlikely to enhance exercise performance capacity in healthy adults.

Low back pain during military service predicts low back pain later in life

The aim of the present study was to assess associations between physician diagnosed unspecified low back pain (LBP) during compulsory military service and self-reported LBP and physical fitness measured on average four years after military service. From a total of 1155 persons who had been pass medical examination for military service and who had completed physically demanding military training between 1997 and 2007, 778 men participated in a refresher military training course and physical tests. In this study, the association between LBP during military service and LBP in later life in addition to the association between LBP and physical fitness were examined. A total of 219 out of 778 participants (28%) had visited a physician due to some musculoskeletal symptom (ICD-10 M-diagnosis) during their military service. Seventy-four participants (9.5%) had visited a physician due to unspecified LBP during their service, and 41 (5.3%) had temporarily been absent from duty due to LBP. At the follow-up examination, 122 (15.7%) had reported LBP during the past month. LBP during military service was associated with self-reported LBP in the follow-up (p = 0.004). Of those who had been absent from duty due to LBP during their military service, 13 (31.7%) reported LBP during the past month. In risk factor analysis, no initial health behaviour and physical performance variables were associated with baseline LBP in the follow-up. The main finding of the present study was that unspecified LBP during military service predicts LBP in later life. On the basis of previous literature, it is also known that LBP is a common symptom and thus, one cannot expect to be symptomless the entire life. Interestingly, none of the health behaviours nor the physical performance studied in the follow-up were associated with baseline LBP. It appears that individuals prone to LBP have symptoms during physically demanding military service and also later in their life.

Sex difference in attractiveness perceptions of strong and weak male walkers

OBJECTIVES

Men and women accurately assess male physical strength from facial and body morphology cues. Women's assessments of male facial attractiveness, masculinity, and dominance correlate positively with male physical strength. A positive relationship also has been reported between physical strength and attractiveness of men's dance movements. Here, we investigate men's and women's attractiveness, dominance, and strength assessments from brief samples of male gait.

METHODS

Handgrip strength (HGS) was measured in 70 heterosexual men and their gait was motion-captured. Men and women judged 20 precategorized strong (high HGS) and weak (low HGS) walkers on attractiveness, dominance, and strength, and provided a measure of their own HGS.

RESULTS

Both men and women judged strong walkers higher on dominance and strength than weak walkers. Women but not men judged strong walkers more attractive than weak walkers. These effects were independent of observers' physical strength.

CONCLUSIONS

Male physical strength is conveyed not only through facial and body morphology, but also through body movements. We discuss our findings with reference to studies suggesting that physical strength provides information about male quality in contexts of inter- and intrasexual selection. Am. J. Hum. Biol. 28:913-917, 2016. © 2016Wiley Periodicals, Inc.

Total and Lower Extremity Lean Mass Percentage Positively Correlates With Jump Performance

Strength and power have been identified as valuable components in both athletic performance and daily function. A major component of strength and power is the muscle mass, which can be assessed with dual-energy x-ray absorptiometry (DXA). The primary purpose of this study was to quantify the relationship between total body lean mass percentage (TBLM%) and lower extremity lean mass percentage (LELM%) and lower extremity force/power production during a countermovement jump (CMJ) in a general population. Researchers performed a DXA analysis on 40 younger participants aged 18-35 years, 28 middle-aged participants aged 36-55 years, and 34 older participants aged 56-75 years. Participants performed 3 CMJ on force platforms. Correlations revealed significant and strong relationships between TBLM% and LELM% compared with CMJ normalized peak vertical ground reaction force (p < 0.001, r = 0.59), normalized peak vertical power (p < 0.001, r = 0.73), and jump height (p < 0.001, r = 0.74) for the combined age groups. Most relationships were also strong within each age group, with some relationships being relatively weaker in the middle-aged and older groups. Minimal difference was found between correlation coefficients of TBLM% and LELM%. Coefficients of determination were all below 0.6 for the combined group, indicating that between-participant variability in CMJ measures cannot be completely explained by lean mass percentages. The findings have implications in including DXA-assessed lean mass percentage as a component for evaluating lower extremity strength and power. A paired DXA analysis and CMJ jump test may be useful for identifying neuromuscular deficits that limit performance.

Physical strength and dance attractiveness: Further evidence for an association in men, but not in women

OBJECTIVES

Physical strength provides information about male quality and can be assessed from facial and body morphology. Research on perception of dance movements indicates that body movement also provides information about male physical strength. These relationships have not been investigated for women.

METHODS

We investigated relationships of handgrip strength (HGS) and dance attractiveness perception in 75 men and 84 women.

RESULTS

We identified positive relationships between HGS and opposite-sex assessments of dance attractiveness for men but not women.

CONCLUSIONS

The replication of previous research investigating relationships between dance attractiveness and physical strength in men corroborates the hypothesis that dance movements provide information about male quality. We argue that these relationships are interpretable in contexts of inter- and intra-sexual selection.

[Low agreement between the fitnessgram criterion references for adolescents]

OBJECTIVE:

To analyze the association and agreement of fitnessgram reference criteria (RC) for cardiorespiratory fitness, body mass index (BMI) and strength in youth.

METHODS:

The study included 781 youth, 386 females, aged 10 to 18 years of Londrina-PR. It were performed cardiorespiratory fitness and muscular strength tests and was calculated body mass index. The association between the tests was analyzed using Poisson regression to obtain prevalence ratio (PR) and confidence intervals of 95%, while agreement of the reference criteria was tested by Kappa index.

RESULTS:

Significant associations were found between cardiorespiratory fitness and BMI (PR=1,49, 1,27-1,75), muscle strength and BMI (PR=1,55, 1,17-2,08), cardiorespiratory fitness and muscle strength (PR=1,81, 1,47-2,24). The agreement between reference criteria ranged from weak to fair, 48.8% (k=0.05, p=0.10) for cardiorespiratory fitness and BMI, 52.9% (k=0.09, p=0.001) for muscle strength and BMI and 38.4% (k=0.22, p<0.001) for cardiorespiratory fitness and muscle strength.

CONCLUSIONS:

Although RC for cardiorespiratory fitness, muscle strength and BMI are associated, the agreement between them ranged from weak to fair. To evaluate health related physical fitness it is suggest the execution of all tests, since each test has specific characteristics.

Musculoskeletal Function and Obesity: Implications for Physical Activity

However quantified, obesity is a global health problem of significant magnitude. The condition is no longer limited to the developed world, with an increasing proportion of low-to-middle income countries burdened by obesity and its comorbidities. Specifically, obesity is a risk factor for a raft of psychosocial, physiological, cardiovascular, and metabolic problems. The carriage of excess body weight, including an unhealthy proportion of body fat, also has important implications for musculoskeletal health. To date, this important relationship has not received as much attention by the research community. Coincidentally, there has been a heightened interest in the role of physical activity and exercise across the lifespan in the prevention, treatment and management of obesity. This paper considers some of the more common musculoskeletal problems in children, adolescents and adults with implications for the overweight and obese and their meaningful engagement in physical activity.

Top 10 research questions related to musculoskeletal physical fitness testing in children and adolescents

The purpose of this article is to bring attention to the 10 most pressing questions relevant to musculoskeletal physical fitness testing in children and adolescents. The goal is to stimulate research to answer these questions. The most pressing needs include establishing definitive links between valid, reliable, and feasible field test measures of muscular strength, endurance, power, and flexibility and health risk factors/markers in children and adolescents; determining the effects of exercise training on these relationships; and documenting the tracking of these relationships. The role of flexibility in health-related physical fitness (HRPF) needs to be carefully and specifically examined. Although body weight/composition is a separate component of health-related fitness, it is also a factor that can influence the performance of musculoskeletal test items. The role of body weight, body fat, and central adiposity and the possibility of adjustment of tests results are important research questions. Several questions relate to which field tests are best for use in schools. Finally, actual health-related criterion-referenced cutoff values need to be developed. In conclusion, more quality research is needed to firmly establish the musculoskeletal area for HRPF in youth.

Rank, job stress, psychological distress and physical activity among military personnel

Background

Physical fitness is one of the most important qualities in armed forces personnel. However, little is known about the association between the military environment and the occupational and leisure-time dimensions of the physical activity practiced there. This study assessed the association of rank, job stress and psychological distress with physical activity levels (overall and by dimensions).

Methods

This a cross-sectional study among 506 military service personnel of the Brazilian Army examined the association of rank, job stress and psychological distress with physical activity through multiple linear regression using a generalized linear model.

Results

The adjusted models showed that the rank of lieutenant was associated with most occupational physical activity (β = 0.324; CI 95% 0.167; 0.481); “high effort and low reward” was associated with more occupational physical activity (β = 0.224; CI 95% 0.098; 0.351) and with less physical activity in sports/physical exercise in leisure (β = −0.198; CI 95% −0.384; −0.011); and psychological distress was associated with less physical activity in sports/exercise in leisure (β = −0.184; CI 95% −0.321; −0.046).

Conclusions

The results of this study show that job stress and rank were associated with higher levels of occupational physical activity. Moreover job stress and psychological distress were associated with lower levels of physical activity in sports/exercises. In the military context, given the importance of physical activity and the psychosocial environment, both of which are related to health, these findings may offer input to institutional policies directed to identifying psychological distress early and improving work relationships, and to creating an environment more favorable to increasing the practice of leisure-time physical activity.