Optimizing exercise prescription during breast cancer rehabilitation in women: Analysis of the load-velocity relationship in the box squat exercise.

The aims of this study were to assess (i) the load-velocity relationship during the box squat exercise in women survivors of breast cancer, (ii) which velocity variable (mean velocity [MV], mean propulsive velocity [MPV], or peak velocity [PV]) shows stronger relationship with the relative load (%1RM), and (iii) which regression model (linear [LA] or polynomic [PA]) provides a greater fit for predicting the velocities associated with each %1RM. Nineteen women survivors of breast cancer (age: 53.2 ± 6.9 years, weight: 70.9 ± 13.1 kg, and height: 163.5 ± 7.4 cm) completed an incremental load test up to one-repetition maximum in the box squat exercise. The MV, MPV, and the PV were measured during the concentric phase of each repetition with a linear velocity transducer. These measurements were analyzed by regression models using LA and PA. Strong correlations of MV with %1RM (R2 = 0.903/0.904; the standard error of the estimate (SEE) = 0.05 m.s-1 by LA/PA) and MPV (R2 = 0.900; SEE = 0.06 m.s-1 by LA and PA) were observed. In contrast, PV showed a weaker association with %1RM (R2 = 0.704; SEE = 0.15 m.s-1 by LA and PA). The MV and MPV of 1RM was 0.22 ± 0.04 m·s-1, whereas the PV at 1RM was 0.63 ± 0.18 m.s-1. These findings suggest that the use of MV to prescribe relative loads during resistance training, as well as LA and PA regression models, accurately predicted velocities for each %1RM. Assessing and prescribing resistance exercises during breast cancer rehabilitation can be facilitated through the monitoring of movement velocity.

Sex and Equipment Impact on Lifting Velocity and the Maximum Repetitions in Bench Press.

This study investigated how equipment and sex affect the prediction accuracy of the maximum number of repetitions performed to failure (RTF) using the fastest mean velocity of the set (MVfastest). Sixteen men and twelve women completed four sessions (two using free-weight equipment and two sessions using the Smith machine). Each session involved three sets of repetitions to failure against the 65%, 75%, and 85% of the one-repetition maximum, interspersed by 10-min of rest. The goodness-of-fit of the individualized RTF-MVfastest relationships was comparable between both equipment types and sexes (P≥0.510). Moreover, there were not significant differences in the MVfastest associated with RTF between equipment types (P≥0.258). However, the MVfastest associated with RTF was higher for men than for women in repetitions 6 to 15 (P≤0.043; ES≥0.69). In addition, the absolute errors when predicting RTF showed no significant differences between equipment types and loads (P<0.444). Specifically, these RTF estimates were within an acceptable range for men (<2 repetitions), but not for women (≥2 repetitions) (main effect of sex: P≤0.018; ES≥0.58). These findings suggest that individualized RTF-MVfastest equations estimate the RTF with an acceptable precision in men during bench press exercises in both equipment types but exhibit lower precision for women.

Kinetic and Kinematic Characteristics Underpinning Change of Direction Performance in Basketball: A Comparative Study Between Sexes and Tests.

ABSTRACT: Baena-Raya, A, Díez-Fernández, DM, Martínez-Rubio, C, Conceição, F, and López-Sagarra, A. Kinetic and kinematic characteristics underpinning change of direction performance in basketball: A comparative study between sexes and tests. J Strength Cond Res 38(4): e182-e188, 2024-This study (a) evaluated the sex-specific kinetic and kinematic outcomes underpinning change of direction (COD) performance, (b) compared these outcomes across 3 different COD tests, and (c) examined the sex-specific and test-specific outcome most strongly related to COD performance in basketball players. Thirty young basketball players (17 males and 13 females) competing at the national level were assessed for the modified 505 test, modified T test, and V-cut test. The Local Positioning System technology (WIMU PRO, Realtrack Systems S.L., Almería, Spain) was used to measure the maximum values of acceleration (ACC max ), deceleration (DEC max ), velocity (VEL max ), and centripetal force (CentF max ) in each COD test. Male players displayed greater ACC max , VEL max , DEC max , and CentF max outputs for each section of the 505 test, T test, and V-cut test (all p < 0.05), resulting in a faster COD performance than females across tests (all ES > -1.42; 95% CI = -3.45 to -0.57). The 505 test demanded significantly greater kinematic outputs than T test and V-cut test for both sexes ( p < 0.01). The ACC max explained ∼26-58% of the variability in COD time for males across tests ( p < 0.05) and 40% in females' modified 505-test time ( p < 0.05). Likewise, in females, DEC max explained 38% of the modified T -test time variability, whereas VEL max explained 53% in the V-cut test time (both p < 0.05). These findings suggest that (a) COD data should not be used interchangeably across sexes, (b) test specificities should be considered for designing COD training, and (c) the kinematic outcomes explaining COD performance might vary across sexes.

Examining Unilateral and Bilateral Exercises through the Load-velocity Relationship.

This study aimed to examine the load-velocity (L-V) relationship in the bench-press (BP) and leg-press (LP) exercises performed unilaterally, and compared this unilateral L-V relationship with the bilateral variants. Nineteen men (age=23.5±2.1 years) completed two incremental tests in BP and LP, performed bilaterally and unilaterally, across two sessions with a 48-hour rest period. We found a close relationship between medium propulsive velocity (MPV) and %1RM in unilateral BP (R2 =0.97, SEE=0.06 m·s-1) and LP (R2=0.96, SEE=0.06 m·s-1). No significant differences were observed between the preferred and non-preferred sides in the L-V relationship for either exercise. Additionally, higher velocities were achieved in unilateral exercises compared to bilateral exercises, particularly with light and moderate loads (30-70%1RM) in BP (p<0.05) and with light loads (30-45%1RM) in LP (p<0.05). Close L-V relationships were observed in unilateral exercises, without differences in the L-V relationships between preferred and non-preferred sides despite the interlimb asymmetries in the absolute strength values. Interestingly, lower velocities were observed at light loads (~30-45% 1RM) for bilateral compared to unilateral exercises, which could be explained by different strength deficits for these exercises.

Does a Resistance Training Program Affect Between-arms Volume Difference and Shoulder-arm Disabilities in Female Breast Cancer Survivors? The Role of Surgery Type and Treatments. Secondary Outcomes of the EFICAN Trial.

OBJECTIVE: The aims were (i) to assess the effects of a 12-week resistance training program on between-arms volume difference and shoulder-arm disabilities in breast cancer survivors and (ii) to evaluate whether the main risk factors for developing cancer-related lymphedema and shoulder-arm disabilities were associated with the effects of the training program. DESIGN: Randomized controlled trial. SETTING: University facilities. PARTICIPANTS: 60 female breast cancer survivors participated. ELIGIBILITY CRITERIA: to be a breast cancer survivor, and to have completed surgery, chemotherapy, and/or radiotherapy up to 10 years before recruitment. EXCLUSION CRITERIA: metastatic breast cancer, a breast reconstruction intervention planned within 6 months, any absolute contraindication for exercise, to perform more than 300 minutes/week of structured exercise. INTERVENTIONS: Participants were randomized to an exercise group (12-week resistance training program) or a control group. MAIN OUTCOME MEASURES: Between-arms volume difference, shoulder-arm disabilities, and upper-limb muscular strength were evaluated at baseline and at week 12. Treatment-related information was registered from medical history. RESULTS: No between-group differences were observed on between-arms volume difference (1.207; 95% CI -0.964, 3.377; P=.270) or shoulder-arm disabilities (2.070; 95% CI -4.362, 8.501; P=.521) after the training program. Likewise, there was no association of surgery type, presence of lymph node resection, chemotherapy, radiotherapy, and hormone therapy with the changes in between-arms volume and perceived shoulder-arm disabilities after the intervention. However, a higher increase in upper limb muscular strength was associated with a reduced shoulder-arm disabilities (-0.429; P=.020) in the exercise group. CONCLUSIONS: The findings suggest that resistance training does not affect between-arms volume difference and shoulder-arm disabilities in female breast cancer survivors. The main risk factors for developing lymphedema were not associated with the effects of the intervention, although a higher increase in upper-limb muscular strength was associated with reduced shoulder-arm disabilities.

Assessing the Maximal Mechanical Capacities Through the Load-Velocity Relationship in Elite Versus Junior Male Volleyball Players.

BACKGROUND: Physical testing is crucial for athlete monitoring, talent identification, optimizing training, and tailoring programs to enhance game-performance in elite competitions. HYPOTHESIS: Load-velocity (L-V) relationship variables discriminate between elite and junior volleyball players, correlate with volleyball-specific performance, and are generalizable across lower- and upper-body exercises. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: A total of 9 elite and 11 junior volleyball players were assessed for the L-V relationship (load-axis intercept [L0], velocity-axis intercept [v0], and area under the L-V relationship line [Aline]) during the countermovement jump (CMJ) and bench press throw (BPT) exercises. Block and spike jump height, as well as standing and jumping spike speed were assessed 24 hours later. RESULTS: Elite players presented greater magnitude in the L-V variables (P ≤ 0.03; effect size [ES] ≥ 1.06) and higher volleyball-specific performance (P ≤ 0.03; ES ≥ 1.09) than juniors (except for CMJ v0 and Aline). The L-V relationship variables were significantly associated with the block and spike jump height and jumping spike speed only in elite players (r ≥ 0.703 and P ≤ 0.04 in 11 out of 18 correlations). No significant associations were observed between CMJ and BPT for any L-V relationship variable (r ≤ 581; P ≥ 0.08, except for Aline in junior players). CONCLUSION: The L-V relationship is a practical procedure to assess volleyball players' maximal mechanical capacities, which are associated with volleyball-specific performance in elite players. However, these data should not be used interchangeably between playing standards or exercises. CLINICAL RELEVANCE: This information might help strength and conditioning coaches to prescribe more effective training programs that focus on developing the specific physical capacities necessary for players to potentially advance to elite status.

Estimating the one-repetition maximum on the leg-press exercise in female breast cancer survivors.

We examined the accuracy of twelve different velocity-based methods for predicting the bilateral leg-press exercise one-repetition maximum (1RM) in breast cancer survivors. Twenty-one female breast cancer survivors (age 50.2 ± 10.8 years) performed an incremental loading test up to the 1RM. Individual load-velocity relationships were modeled by linear and quadratic polynomial regression models considering the mean velocity (MV) and peak velocity (PV) values recorded at five incremental loads (~45-55-65-75-85% of 1RM) (multiple-point methods) and by a linear regression model considering only the two distant loads (~45-85% of 1RM) (two-point method). The 1RM was always estimated through these load-velocity relationships as the load associated with a general (MV: 0.24 m/s; PV: 0.60 m/s) and an individual (MV and PV of the 1RM trial) minimal velocity threshold (MVT). Compared to the actual 1RM, the 1RMs estimated by all linear regression models showed trivial differences (Hedge's g ranged from 0.08 to 0.17), very large to nearly perfect correlations (r ranged from 0.87 to 0.95), and no heteroscedasticity of the errors (coefficient of determination (r2) < 0.10 obtained from the relationship of the raw differences between the actual and predicted 1RMs with their average value). Given the acceptable and comparable accuracy for all 1RM linear prediction methods, the two-point method and a general MVT could be recommended to simplify the testing procedure of the bilateral leg-press 1RM in breast cancer survivors.

Load-Time and Load-Speed Relationship in the Resisted Sled Sprint Exercise: What Independent Variable Most Accurately Determines the Relative Load?

ABSTRACT: Jiménez-Lozano, M, Yáñez-García, JM, Mora-Custodio, R, Valle-Salguero, A, Díez-Fernández, DM, Franco-Márquez, F, González-Badillo, JJ, and Rodríguez-Rosell, D. Load-time and load-speed relationship in the resisted sled sprint exercise: what independent variable most accurately determines the relative load? J Strength Cond Res 37(11): 2167-2177, 2023-The aims of this study were to analyze the load-speed and load-time relationships in the resisted sled sprint exercise using different variables as relative load and to estimate the decrement of speed sprint and the increase of sprint time across different loads. Thirty young healthy men performed a progressive loading test in the countermovement jump (CMJ) exercise to determinate the load that elicited a 2 m·s-1 peak velocity (PV2-load) and in the full squat exercise to obtain the 1 repetition maximum (1RM) value and the load that elicited a 1 m·s-1 mean velocity (V1-load). In addition, subjects performed a progressive loading test in the resisted sled sprint exercise, whereas time and instantaneous speed at 10 (T10 and V10) and 20 m (T20 and V20) were measured. The independent variables used were body mass (BM), 1RM and V1-load in the squat exercise, the PV2-Load in the loaded CMJ exercise, 1RM + BM, V1-Load + BM, and PV2-Load + BM. To analyze whether relationships were dependent on individual performance obtained in unloaded sprint, the total sample was divided into 3 subgroups: high performance (T20 < 3.00 s), medium performance (T20:3.00-3.12 s), and low performance (T20 > 3.12 seconds) groups. The independent variables showing the highest relationships with time and speed in 10 and 20 m were %BM, %BM + V1-load, and %BM + PV2-load. Statistically significant differences between performance groups in %DSS (decrease of sprint speed) and %IST (increase sprint time) in 20 m were found when %BM was used as relative load, whereas there were no significant differences between groups for %BM + PV2-load or %BM + V1-load. In conclusion, the use of %BM + PV2-load and %BM + V1-load should be considered as variables for monitoring the relative load in the resisted sled sprint exercise.

Acute Mechanical and Skin Temperature Responses to Different Interrepetition Rest Intervals During Full-Squat Exercise.

PURPOSE: This study aimed to (1) evaluate the acute effects of different interrepetition rest full-squat protocols on countermovement jump (CMJ) height, velocity loss (VL), and skin temperature (Tsk) and (2) determine whether the VL, the changes in Tsk, or the individual strength level is associated with the change in CMJ height. METHODS: Sixteen resistance-trained men randomly performed 3 squat protocols at maximal intended velocity with 60% of the 1-repetition maximum (sets × repetitions [interrepetition rest]): traditional (2 × 6 [0 s]), cluster 2 (2 × 6 [30 s every 2 repetitions]), and cluster 1 (1 × 12; [36 s every repetition]), plus a control session. CMJ height was assessed before and 2, 4, and 8 minutes after the protocols. RESULTS: There was a significant main effect of protocol for the VL (F = 20.54, P < .001) and loss in mean power (F = 12.85, P < .001; traditional > cluster 2 > cluster 1). However, we found a comparable reduction of CMJ height after 8 minutes: traditional (-3.4% [4.2%]), cluster 2 (-5.3% [4.9%]), cluster 1 (-5.4% [2.9%]), and control (-4.2% [3.6%]). Overall, mean Tsk acutely decreased after all the protocols. Higher individual strength level (but not VL or the changes in Tsk) was associated with lower CMJ-height loss (P < .05). CONCLUSIONS: Although different interrepetition rest full-squat protocols may alter the loss in velocity and power, they result in a similar decrease in Tsk and CMJ height, which could be more influenced by individual strength level than VL or changes in Tsk.

Physical-Performance Changes Over the Season: Are They Related to Game-Performance Indicators in Elite Men Volleyball Players?

BACKGROUND: The development and influence of physical capabilities and game action performance over the course of the season are a big challenge for coaches and players. PURPOSE: The aims of the present study were to examine (1) the seasonal changes in the physical capabilities (mechanical and kinematic) and game-performance indicators in top-level men volleyball players and (2) the relationship between these physical capabilities and game-performance indicators in official matches. METHODS: Eleven top-level players participated. Players were physically tested 3 times during the season. Before each test, players' match performance (11 sets) was analyzed according to the level of opposition and match location. The percentage of change, statistical differences over the season (Friedman and Wilcoxon tests), and associations between variables (Spearman r) were calculated (P < .05) among mechanical (force-velocity profile during vertical jump and bench press), kinematic (jump height and spike ball speed), and game action performance features (coefficient, efficacy, and percentage of errors in serve, attack, and block). RESULTS: The theoretical maximal force and velocity during vertical jump and bench press, respectively; the peak spike ball speed; and the serve efficacy significantly increased over the season. Moreover, there was a significant reduction in serve errors as the jump height increased (r = -.44; P = .026), as well as a significant increase in serve errors as the peak spike ball speed increased (r = -.62; P = .001). CONCLUSION: These findings reveal how the physical and game action performance variables evolve and interact during the season. This may help coaches and trainers to monitor and analyze the most relevant volleyball performance factors.

Effects of a Physical Exercise Programme through Service-Learning Methodology on Physical Activity, Physical Fitness and Perception of Physical Fitness and Health in University Students from Spain: A Preliminary Study.

The practice of physical activity has been reported on countless occasions for the benefits it has on people's holistic health. However, today's society has high levels of inactivity and sedentary lifestyles, which highlights the importance of promoting active and healthy states in the population. As a mechanism to improve body composition, physical condition and perceived values of one's own physical condition and health status, the implementation of a strength training programme in the university community was proposed using a methodology based on Service-Learning. The participants were 12 students as coaches and 57 students from different university degrees as coachees (17 boys and 40 girls); the ages of the participants ranged from 18 to 33 years (M = 22.00; SD = 2.96). The variables of body composition, physical fitness, physical activity level and perception of fitness and health were assessed. Differences between pre- and post-intervention results were analysed using the Student's t-test and Wilcoxon test for ordinal self-perception variables. The results showed significant improvements in all the variables evaluated after the intervention. In conclusion, we would like to highlight the benefits of physical activity and the need to continue implementing action and intervention plans to encourage and promote its practice in all sectors of the population.

Novel Curvilinear Sprint Test in Basketball: Reliability and Comparison With Linear Sprint.

ABSTRACT: Baena-Raya, A, Díez-Fernández, DM, López-Sagarra, A, Martínez-Rubio, C, Soriano-Maldonado, A, and Rodríguez-Pérez, MA. Novel curvilinear sprint test in basketball: reliability and comparison with linear sprint. J Strength Cond Res 37(9): e535-e540, 2023-This study (a) evaluated the reliability of a curvilinear sprint (CS) test to assess kinetic and kinematic outcomes in basketball players, (b) compared the kinetic and kinematic outcomes derived from curvilinear vs. linear sprints (LS), and (c) examined the association of both the CS and LS with change of direction (COD) performance. Thirty young basketball players (17 men and 13 women) competing at the national level (i.e., Spanish Basketball National League) performed a novel CS test around the 3-point line (the 3-point line CS test) to the right and left sides. The maximum and average values of acceleration (ACC), velocity (VEL), and centripetal force (CentF) were measured using Local Positioning System technology (WIMU PRO, Realtrack Systems S.L., Almería, Spain). All outcomes showed a high relative (intraclass correlations coefficient ≥ 0.90) and absolute (coefficient of variation [CV] < 5%) reliability, except the maximal CentF to the right (CV = 5.41%) and left sides (CV = 7.72%). Linear sprints displayed higher ACC and VEL outputs compared with the 3-point line CS test (all p < 0.001). Both sprinting tests were very large to nearly perfect associated with COD performance (LS r range from -0.71 to -0.86; CS r range from -0.68 to -0.94; p < 0.001), and the curvilinear ACC max was the kinematic outcome most strongly associated with COD performance ( r range from -0.73 to -0.94). In conclusion, the 3-point line CS test is reliable to measure CS performance in basketball and presents different kinetic and kinematic features than LS.

Effects of a 12-week supervised resistance training program, combined with home-based physical activity, on physical fitness and quality of life in female breast cancer survivors: the EFICAN randomized controlled trial.

PURPOSE: This study assessed the effects of 12-week supervised resistance training combined with home-based physical activity on physical fitness, cancer-related fatigue, depressive symptoms, health-related quality of life (HRQoL), and life satisfaction in female breast cancer survivors. METHODS: A parallel-group, outcome assessor-blinded, randomized controlled trial included 60 female breast cancer survivors who had completed their core treatments within the previous 10 years. Through computer-generated simple randomization, participants were assigned to resistance training (RTG; two sessions/week for 12 weeks plus instructions to undertake ≥ 10,000 steps/d) or control (CG; ≥ 10,000 steps/d only). Outcomes were evaluated at baseline and week 12. Muscular strength was assessed with electromechanical dynamometry. A standardized full-body muscular strength score was the primary outcome. Secondary outcomes included cardiorespiratory fitness, shoulder mobility, cancer-related fatigue, depressive symptoms, HRQoL, and life satisfaction. RESULTS: Thirty-two participants were assigned to RTG (29 achieved ≥ 75% attendance) and 28 to CG (all completed the trial). Intention-to-treat analyses revealed that the standardized full-body muscular strength score increased significantly in the RTG compared to the CG (0.718; 95% CI 0.361-1.074, P < 0.001, Cohen's d = 1.04). This increase was consistent for the standardized scores of upper-body (0.727; 95% CI 0.294-1.160, P = 0.001, d = 0.87) and lower-body (0.709; 95% CI 0.324-1.094, P = 0.001, d = 0.96) strength. There was no effect on cardiorespiratory fitness, shoulder flexion, cancer-related fatigue, depressive symptoms, HRQoL, or life satisfaction. The sensitivity analyses confirmed these results. CONCLUSION: and implication for cancer survivors. In female breast cancer survivors who had completed their core treatments within the past 10 years, adding two weekly sessions of supervised resistance training to a prescription of home-based physical activity for 12 weeks produced a large increase in upper-, lower-, and full-body muscular strength, while other fitness components and patient-reported outcomes did not improve. TRIAL REGISTRATION NUMBER: ISRCTN14601208.

Can the Supido Radar Be Used for Measuring Ball Speed during Soccer Kicking? A Reliability and Concurrent Validity Study of a New Low-Cost Device.

The aim was to analyze the reliability and validity of a low-cost instrument, based on a radar system, to quantify the kicking ball speed in soccer. A group of 153 male soccer players (under-13, n = 53; under-15, n = 54; under-18, n = 46) participated in this study. Each player performed three kicks on the goal in a standardized condition while the ball speed was measured with three different devices: one Radar Stalker ATS II® (reference criterion) and two Supido Radar® (Supido-front of the goal and Supido-back of the goal). The standard error of measurement (SEM) expressed as a coefficient of variation (CV) and the intraclass correlation coefficient (ICC) were employed for assessing the reliability of each instrument. Stalker and Supido-back showed very high absolute (CV = 4.0-5.4%) and relative (ICC = 0.945-0.958) reliability, whereas Supido-front resulted in moderate to low reliability scores (CV = 7.4-15%, ICC = 0.134-0.693). In addition, Lin's concordance correlation coefficient (CCC) values revealed an 'almost perfect' agreement between Stalker and Supido-back for the average (r = 0.99) and maximal (r = 0.98) ball speed, regardless of the ball speed range analyzed. However, Supido-front resulted in a poor degree of concordance (CCC = 0.688) and a high magnitude of error (17.0-37.5 km·h-1) with the reference Stalker radar gun. The Supido Radar® placed behind the goal could be considered a reliable and valid device for measuring ball speed in soccer.

Improving resistance training prescription through the load-velocity relationship in breast cancer survivors: The case of the leg-press exercise.

The aims of this study were: (i) to analyse the load-velocity relationship in the bilateral leg-press exercise in female breast cancer survivors, (ii) to assess whether mean velocity (MV) or peak velocity (PV) show stronger relationship with the relative load, and (iii) to examine whether linear (LA) or polynomic (PA) adjustment predict the velocities associated with each %1RM with greater precision. Twenty-two female breast cancer survivors (age: 50.2 ± 10.8 years, weight: 69.6 ± 15.2 kg, height: 160.51 ± 5.25 cm) completed an incremental load test until 1RM in the bilateral leg-press exercise. The MV and the PV of the concentric phase were measured in each repetition using a linear velocity transducer, and were analysed by regression models using LA and PA. A very close relationship of MV (R2 = 0.924; p < 0.0001; SEE = 0.08m.s-1 by LA, and R² = 0.952; p < 0.0001; SEE = 0.063 m.s-1 by PA) and PV (R² = 0.928; p < 0.0001; SEE = 0.119 m.s-1 by LA and R² = 0.941; p < 0.0001; SEE = 0.108 m.s-1 by PA) with %1RM were observed. The MV of 1RM was 0.24 ± 0.03 m·s-1, whereas the PV at 1RM was 0.60 ± 0.10 m.s-1. A comprehensive analysis of the bilateral leg-press load-velocity relationship in breast cancer survivors is presented. The results suggest that MV is the most recommendable velocity variable to prescribe the relative load during resistance training, and that the PA presents better accuracy to predict velocities associated with each %1RM, although LA is sufficiently valid to use this model as an alternative to the quadratic model. The implications for resistance training in breast cancer are discussed.Highlights The load-velocity relationship in the bilateral leg-press exercise was described in female breast cancer survivors.The mean velocity is the most recommendable velocity variable to prescribe the relative load during resistance training in this population.The polynomial adjustment presents a better accuracy to predict velocities associated with each %1RM, although the linear adjustment is sufficiently valid as an alternative.This study will likely contribute to improving exercise prescription and monitoring in breast cancer survivors.

Absolute and Relative Handgrip Strength as Indicators of Self-Reported Physical Function and Quality of Life in Breast Cancer Survivors: The EFICAN Study.

BACKGROUND: Although breast cancer (BC) is the most prevalent type of cancer in the world, its high survival rate implies that many people live long after the treatments and face their side effects. The physical function (PF) and health-related quality of life (HRQoL) of people surviving BC decreases significantly, which makes important to identify markers that may be associated with a better health status and prognosis. Previous studies suggest that handgrip strength (HGS) and HGS relative to the body mass index (rHGS) are good indicators of PF and HRQoL in different populations. However, it is unknown whether this applies to BC survivors. This study aimed to evaluate the association of HGS and rHGS with PF and HRQoL in this population. METHODS: Sixty female BC survivors participated. Handgrip strength was assessed with a dynamometer. Arm volume was estimated and upper limb impairments, as well as cancer-related fatigue, depression, life satisfaction and HRQoL, were assessed using standardized questionnaires. RESULTS: Higher levels of HGS and rHGS were associated with higher levels of HRQoL, lower cancer-related fatigue, and fewer problems with the affected arm. CONCLUSIONS: These results suggest that HGS may be a good indicator of self-reported PF and HRQoL in female BC survivors.

¿Es la fuerza de prensión manual un buen indicador de condición física y composición corporal en pacientes con cáncer de mama que han terminado los tratamientos centrales de la enfermedad? Estudio EFICAN / A força de preensão manual é um bom indicador da condição física e da composição corporal em doentes com cancro da mama que completaram os tratamentos centrais da doença? Estudo EFICAN / Is handgrip strength a good indicator of physical fitness and body composition in breast cancer patients who have completed their core treatments? The EFICAN study

Objetivo: evaluar la asociación entre la fuerza de prensión manual (FPM) y diversos parámetros de condición física y composición corporal en mujeres supervivientes de cáncer de mama.Método: se realizó un estudio transversal con los datos basales del ensayo clínico EFICAN (Ejercicio FÍsico para supervivientes de CÁNcer de mama). Participaron 60 mujeres supervivientes de cáncer de mama que habían terminado los tratamientos centrales de la enfermedad en los 10 años previos al comienzo del estudio, que no presentaban enfermedad pulmonar o cardiovascular, cáncer de mama metastásico, ni tenían prevista una intervención para reconstrucción mamaria en un plazo de 3 meses desde el comienzo del estudio. Se evaluó la fuerza de prensión manual mediante dinamometría manual, la fuerza muscular isométrica pico mediante dinamometría electromecánica funcional, el fitness cardiorrespiratorio (VO2máx) se estimó a través del Siconolfi step test, la amplitud de movimiento (ADM) en flexión de hombro mediante goniometría digital, y la composición corporal mediante bioimpedancia.Resultados: se observó una asociación positiva de la FPM con la masa muscular (r=0.423), y con la fuerza isométrica de miembro superior (r=0.523) e inferior (r=0.335), y una asociación negativa de la FPM con el porcentaje de grasa corporal (r=-0.405). Sin embargo, no se encontró asociación entre FPM y VO2máx ni ADM del hombro (P>0.05).Conclusiones: estos resultados sugieren que la FPM puede ser un buen indicador de fuerza muscular, así como de composición corporal en mujeres supervivientes de cáncer de mama. Futuros estudios prospectivos deberán evaluar el valor predictivo de la FPM en esta población. (AU)

Objectives: this study evaluated the association between handgrip strength (HGS) and various parameters of physical fitness and body composition in female breast cancer survivors.Methods: a cross-sectional study was conducted with the baseline data from the EFICAN (Ejercicio FÍsico para supervivientes de CÁNcer de mama) clinical trial. 60 female breast cancer survivors who had completed the core treatments of the disease in the 10 years prior to the study beginning, who didn’t have any cardiovascular or pulmonary disease, metastatic breast cancer or awaited breast cancer reconstruction in the following 3 months, participated. Handgrip strength was assessed using a digital dynamometer, peak isometric strength was determined using an electromechanical dynamometer, cardiorespiratory fitness (VO2máx) was estimated through the Siconolfi step test, shoulder flexion mobility was assessed through digital goniometry and body composition was determined using a bioelectrical impedance device.Results: positive associations between HGS and muscle mass (r=0.423), isometric upper-limb (r=0.523) and lower-limb (r=0.335) strength were found, and a negative association between HGS and fat mass percentage (r=-0.405) was also found. However, no associations between HGS and VO2máx or shoulder flexion mobility were found (P>0.05).Conclusions: these results suggest that HGS may be a good indicator of muscular strength and body composition in female breast cancer survivors. Future prospective studies are needed to assess the predictive value of HGS in this population. (AU)

Objetivo: avaliar a associação entre a força de preensão manual (FPM) e vários parâmetros de condição física e composição corporal em mulheres sobreviventes de cancro da mama.Método: foi realizado um estudo transversal utilizando dados de base do ensaio clínico EFICAN (Physical Exercise for Breast Cancer Survivors). Participaram sessenta mulheres sobreviventes de cancro da mama que tinham concluído os tratamentos centrais da doença nos 10 anos anteriores ao início do estudo, que não tinham doenças pulmonares ou cardiovasculares, cancro da mama metastásico, ou que não estavam programadas para se submeterem à reconstrução da mama nos 3 meses seguintes ao início do estudo. A força de preensão manual foi avaliada por dinamometria manual, o pico de força muscular isométrica por meio de dinamometria electromecânica funcional, a capacidade cardiorrespiratória (VO2máx) foi estimada pelo Siconolfi step test, a amplitude de movimento (ADM) em flexão do ombro por meio de goniometria digital, e a composição corporal por bioimpedância.Resultados: observámos uma associação positiva de FPM com massa muscular (r=0,423), e com força isométrica de membro superior (r=0,523) e membro inferior (r=0,335), e uma associação negativa de FPM com percentagem de gordura corporal (r=-0,405). Contudo, não foi encontrada qualquer associação entre FPM e VO2max ou ADM de ombro (P>0.05).Conclusões: estes resultados sugerem que a FPM pode ser um bom indicador da força muscular, bem como da composição corporal das mulheres sobreviventes de cancro da mama. Os futuros estudos prospectivos devem avaliar o valor preditivo do FPM nesta população. (AU)

Analysis of the Load-Velocity Relationship in Deadlift Exercise.

The aim of this study was to analyze the relationship between movement velocity and relative load (%1RM) in the deadlift exercise. Fifty men (age = 23.8 ± 3.6 years, body mass = 78.2 ± 8.3 kg, height = 1.78 ± 0.06 m) performed a first evaluation (T1) consisting of a one-repetition maximum (1RM) test. Forty-two subjects performed a second evaluation (T2) after 6 weeks. Mean (MV), mean propulsive (MPV) and peak (PV) velocity measures of the concentric phase were analyzed. Load-velocity relationships were studied by fitting first order equations to the data using loads from 30-100% of 1RM. A comprehensive set of statistics for assessing bias and level of agreement to estimate the 1RM value from the different models was used. Stability of these relationships was assessed using the coefficient of variation (CV) and the intraclass correlation coefficient (ICC). General load-velocity equations provided good adjustments (R2 ~; 0.91-0.93), however individual load-velocity regressions provided better adjustments (R2 ~; 0.97). Individual estimations also showed higher agreement and more regular variation than general equations. Moreover, MPV showed smaller bias than the other velocity parameters (MV and PV). The stability analysis of the load-velocity relationships resulted in ICC values higher than 0.82 and CV lower than 3.0%. Monitoring repetition velocity allows estimation of the %1RM in the deadlift exercise. More accurate predictions of relative load can be obtained when using individualized regression equations instead of general equations.

Physical appearance comparisons and symptoms of disordered eating: The mediating role of social physique anxiety in Spanish adolescents.

Physical appearance comparisons (PAC) and social physique anxiety (SPA) have been independently related to disordered eating (DE). However, the extent to which these variables may be concurrently associated with DE in the adolescent population remains largely unknown. This study was aimed at addressing a twofold objective: firstly, to examine whether SPA may moderate or mediate the relationship between PAC and DE in a sample of Spanish adolescents of both sexes; secondly, to examine whether these mechanisms may differ according to sex. A total of 738 adolescents (50% girls) ranging from 12 to 17 years of age (M = 14.45, SD = 1.50) were recruited from nine secondary schools. Participants completed a self-reported questionnaire covering the variables of interest. After controlling for the effects of sex, age, standardized body mass index (z-BMI), and depressive symptoms, the results from bootstrapping cross-sectional regression analyses supported the mediating effect of SPA on the relationship between PAC and DE, but not the moderating one. Sex was not found to moderate either the mediated or moderated relationships. Prevention/intervention efforts targeted towards decreasing DE among adolescents may benefit from minimizing the social relevance of the body inherent in the cognitive and affective processes underlying both SPA and PAC.

Effects of a 12-week resistance and aerobic exercise program on muscular strength and quality of life in breast cancer survivors: Study protocol for the EFICAN randomized controlled trial.

BACKGROUND: The number of people living with the side effects of breast cancer treatment (eg, loss of muscular mass and muscular strength, upper-limb mobility and disability, lymphedema, cardiac toxicity, and reduced quality of life) is increasing yearly. These consequences can be improved through exercise, specially combining resistance and aerobic training. Previous exercise trials have not been consistent in applying training principles and standardized reporting, and this partly explains the variability in obtained results. The aim of this study is to assess the effect of a 12-week supervised resistance exercise program combined with home-based aerobic exercise, compared with home-based aerobic exercise only, on muscular strength and several aspects of health-related quality of life in breast cancer survivors. To maximize transparency, replicability, and clinical applicability, the intervention is described following the consensus on exercise reporting template. METHODS: This study is a parallel-group randomized controlled trial in which 60 female breast cancer survivors, who have completed central treatments of the disease in the last 5 years, will be randomly assigned to either an experimental group that will perform a total of 24 progressive resistance training sessions for 12 weeks (ie, 2 weeks of individual training and 10 weeks of micro-group training) and will be requested to undertake 10,000 steps/d, or a control group that will be requested to undertake 10,000 steps/d, only. Outcomes will be evaluated at baseline and at week 12. Primary outcome measure is peak isometric muscular strength of the lower- and upper-body, assessed with several exercises through an electromechanical dynamometer. Secondary outcomes include cardiorespiratory fitness, upper-joint mobility and disability, health-related quality of life, cancer-related fatigue, depression, life satisfaction, and presence of lymphedema. DISCUSSION: This study aims to investigate the extent to which a 12-week supervised and progressive resistance exercise program, in addition to home-based aerobic physical activity, might improve muscular strength and health-related quality of life in breast cancer survivors. The comprehensive description of the intervention will likely contribute to enhancing exercise prescription in this population. TRIAL REGISTRATION NUMBER: ISRCTN14601208.