Agreement between fat-free mass from bioelectrical impedance analysis and dual-energy X-ray absorptiometry and their use in estimating resting metabolic rate in resistance-trained men.

BACKGROUND: This study aimed to determine the agreement between fat-free mass (FFM) estimates from bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) and their use in estimating resting metabolic rate (RMR) in men undergoing resistance training. METHODS: Thirty healthy resistance-trained men (22.7 ± 4.4 years, 70.0 ± 8.7 kg, 174.6 ± 6.7 cm, and 22.9 ± 2.3 kg/m2) were evaluated. The equation developed by Tinsley et al. (RMR = 25.9 × fat-free mass [FFM] + 284) was adopted to calculate the RMR. DXA was used as the reference method for FFM. RESULTS: Furthermore, FFM was also estimated by BIA using a spectral device. No significant difference (p > 0.05) was observed between DXA (1884.2 ± 145.5 kcal) and BIA (1849.4 ± 167.7 kcal) to estimate RMR. A positive and significant correlation (r = 0.89, p < 0.05) was observed between DXA and BIA estimates of RMR. The mean difference between methods indicated that BIA presented a bias of -34.8 kcal. CONCLUSION: These findings suggest that using FFM derived from DXA or BIA results in similar RMR estimates in resistance-trained men.

Effects of resistance training on body recomposition, muscular strength, and phase angle in older women with different fat mass levels.

AIMS: The concomitant increase in skeletal muscle mass (SMM) and decrease in fat mass has been termed body recomposition. This study aimed to analyze the influence of pre-training levels of fat mass on body recomposition, muscular strength, and (phase angle) PhA after 24 weeks of resistance training (RT) in older women. METHODS: Data from 99 older women (68.6 ± 5.7 years, 65.7 ± 8.6 kg, 155.1 ± 5.8 cm, 27.2 ± 3.1 kg/m2) was retrospectively analyzed. Participants were separated into tertiles according to the amount of fat mass at baseline as follows: low fat mass (L-FM, n = 33), moderate fat mass (M-FM, n = 33), and high fat mass (H-FM, n = 33). The participants underwent a RT program consisting of eight exercises, three sets per exercise, with a load between 8 and 15 RM, performed three times per week for 24 weeks. The SMM and fat mass were evaluated by dual-energy X-ray absorptiometry (DXA). Body recomposition was determined by the composite Z-score of changes in SMM and fat mass. One repetition maximum (1RM) tests in chest press, knee extension, and preacher curl were assessed to verify muscular strength. Bioimpedance was used to determine phase angle. RESULTS: Results indicated that after the RT period, a greater positive body recomposition was observed in the L-FM group than in M-FM and H-FM groups. Moreover, all groups increased muscular strength and phase angle with no significant difference among groups (P > 0.05). CONCLUSION: The present study results suggest that the initial amount of fat mass influences the body recomposition induced by RT in older women, with those with lower pre-training fat mass levels presenting higher levels of body recomposition. However, improvements in muscular strength and phase angle are not dependent on the amount of initial fat mass in older women.

Assessing full body impulsive ability using a range of medicine ball loads for the backward overhead medicine ball throw.

The potential for high performance in many sports can be assessed by quantifying whole-body explosiveness. The backwards overhead medicine ball (BOMB) throw is commonly-used to tests this ability, but the effect of varied loading on test execution is unknown. The purpose of this study was to determine the effect of different medicine ball (MB) loads on force, velocity, and power output during the BOMB throw. Female collegiate softball and rugby players (n=31) performed the BOMB throw on a force plate using 2.7, 3.6, 4.5, and 5.5 kg MBs, with three throws per load in a randomised order, and 30 seconds rest between throws. A series of Repeated Measures ANOVAs noted no differences (p>0.05) in peak power, peak force, peak velocity, force at the moment of peak power, or velocity at the moment of peak power, across MB loads. The lack of differences among these loads indicates that coaches can likely compare kinetic characteristics of the BOMB throw within this range (2.7-5.5 kg). Therefore, coaches can use the BOMB throw with 2.7-5.5 kg MBs for training or measurement among female athletes to obtain reference data for programming or evaluation.

Effect of Resistance Exercise Orders on Health Parameters in Trained Older Women: A Randomized Crossover Trial.

PURPOSE: This study aimed to compare the effects of four resistance exercise orders on muscular strength, body composition, functional fitness, cardiovascular risk factors, and mental health parameters in trained older women. METHODS: The intervention lasted 63 wk. Sixty-one physically independent women (>60 yr) after completing a 12-wk resistance training (RT) preconditioning phase were randomized into four different exercise orders groups to perform 12 wk of RT: multijoint to single-joint and upper- to lower-body, single-joint to multijoint and upper- to lower-body, multijoint to single-joint and lower- to upper-body, and single-joint to multijoint and lower- to upper-body. This was followed by a 12-wk detraining period and another 12-wk RT in which exercise orders were crossed over between MJ-SJ and SJ-MJ conditions. Body composition (dual-energy x-ray absorptiometry), muscular strength (one-repetition maximum tests), functional fitness (gait speed, walking agility, 30-s chair stand, and 6-min walk tests), cardiovascular risk factors (glucose, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, C-reactive protein, advanced oxidation protein product, total radical-trapping antioxidant parameter, and nitric oxide), depressive (Geriatric Depression Scale) and anxiety symptoms (Beck Anxiety Inventory), and cognitive performance (Montreal Cognitive Assessment, Trail Making, verbal fluency, and Stroop test) were analyzed. RESULTS: After the final training period, all groups presented significant improvements ( P < 0.05) in almost all analyzed variables (muscular strength, body composition, functional tests, blood biomarkers, and mental health parameters), without significant difference among exercise orders. CONCLUSIONS: Our results suggest that RT exercise orders in which MJ, SJ, upper, or lower-body exercises are performed first have similar effects on health parameters in trained older women.

Differential Responsiveness for Strength Gain Between Limbs After Resistance Training in Older Women: Impact on Interlimb Asymmetry Reduction.

ABSTRACT: Nunes, JP, Marcori, AJ, Ribeiro, AS, Cunha, PM, Kassiano, W, Costa, BDV, Aguiar, AF, Nakamura, M, Mayhew, JL, and Cyrino, ES. Differential responsiveness for strength gain between limbs after resistance training in older women: Impact on interlimb asymmetry reduction. J Strength Cond Res 36(11): 3209-3216, 2022-The present study compared strength responses between preferred (PREF) and nonpreferred (N-PREF) legs in older women. Muscular strength was measured unilaterally using an isokinetic dynamometer and was analyzed for reproducibility scores, acute performance, and responsiveness to a resistance training (RT) program. One hundred eleven women (aged ≥60 years) performed 12 weeks of whole-body RT (3 times a week; 4 lower-body exercises). Reproducibility scores (intraclass correlation coefficient ≥0.920; following test-retests in part of the sample at pretraining; n = 19), average acute performances, and average strength gains (PREF = ∼6.9%; N-PREF = ∼7.2%) were similar between legs (p > 0.05). However, the individual analyses showed that some subjects were considered responders to strength gains in 1 leg, whereas nonresponders in the other. Nonetheless, when considering the responses in all strength tests, most subjects (91%) were considered responder to at least 1 measure. In addition, it was observed that the strength ratio between PREF/N-PREF legs was altered for those who presented some asymmetry at baseline, as the limbs became more symmetrical in all strength measures after the RT. In conclusion, we observed that some older women may have different levels of strength between legs; however, a traditional 12-week RT program with bilateral exercises can reduce such asymmetry by inducing greater strength gains in the weaker leg.

Momentum, Rather Than Velocity, Is a More Effective Measure of Improvements in Division IA Football Player Performance.

ABSTRACT: Mann, JB, Mayhew, JL, Dos Santos, ML, Dawes, JJ, and Signorile, JF. Momentum, rather than velocity, is a more effective measure of improvements in Division IA football player performance. J Strength Cond Res 36(2): 551-557, 2022-Speed, or the time to complete straight runs or agility drills, is commonly used to assess performance in collegiate American football players. However, it is common for players' speeds to plateau by the second year of eligibility, whereas their body masses continue to increase. The purpose of this study was to track change in speed, body mass, and momentum (body mass · velocity), across Division 1 football players' 4-year careers (n = 512). Complete data were derived for the 40-yd sprint (n = 82), the proagility shuttle (n = 73), and the L drill (n = 73) from the same NCAA Division 1 team over a 15-year period. Significant changes were seen for velocity between year 1 and the next 3 playing years (p < 0.05), with no differences between years 2 and 4, whereas body mass increased significantly across all playing years (p < 0.05). Further momentum increased across all years for all tests (p < 0.0001). These results indicate the importance of including changes in body mass when evaluating performances during sprints and change of direction drills. Our results also suggest that using sprint or agility drill times to evaluate playing potential across football players' collegiate careers may be ineffective and can provide players with a false and disheartening picture of their improvements across their careers. Momentum, which incorporates training-induced increases in both speed and body mass, would be a more relevant and supportive measure of players' improvements. In addition, the simple computation of this variable, using existing speed and body mass data, may be an important addition to the National Football League combine as a measure of playing potential in the professional game.

Comparison of 2 Weekly Frequencies of Resistance Training on Muscular Strength, Body Composition, and Metabolic Biomarkers in Resistance-Trained Older Women: Effects of Detraining and Retraining.

ABSTRACT: Amarante do Nascimento, M, Nunes, JPA, Pina, FLC, Ribeiro, AS, Carneiro, NH, Venturini, D, Barbosa, DS, Mayhew, JL, and Cyrino, ES. Comparison of 2 weekly frequencies of resistance training on muscular strength, body composition, and metabolic biomarkers in resistance-trained older women: Effects of detraining and retraining. J Strength Cond Res 36(5): 1437-1444, 2022-This study aimed to compare the effects of 2 weekly frequencies of resistance training (RT) on muscular strength, body composition, and metabolic biomarkers in previously resistance-trained older women after detraining and retraining. Forty subjects (>60 years) performed RT (8 exercises, 1 set of 10-15 repetitions maximum) 2 (G2x) or 3 (G3x) times per week over 12 weeks of training and retraining. After training, subjects were detrained for 12 weeks. After detraining, there were significant decreases (p < 0.05) in upper-body (∼12%) and lower-body (∼14%) muscular strength, fat-free mass (FFM) (∼2%), and testosterone (∼26%), whereas increases were revealed for fat mass (FM) (∼4%), relative body fat (∼3%), fasting glucose (∼8%), low-density lipoprotein cholesterol (LDL-C) (∼21%), and triglycerides (∼24%), with no differences between groups (p > 0.05). Following retraining, there were significant increases (p < 0.05) for upper (∼7%) and lower (∼10%) muscular strength, FFM (∼2%), and testosterone (∼20%). In contrast, decreases were found for FM (∼7%), relative body fat (∼3%), fasting glucose (∼6%), LDL-C (∼14%), and triglycerides (∼21%), also with no differences between groups (p > 0.05). Gains after retraining were lower than after training (p < 0.05) only for upper- and lower-body muscular strength (∼6%) and testosterone (∼11%). Total cholesterol, high-density lipoprotein cholesterol, IGF-1, and C-reactive protein did not change at any point in the study for either group (p > 0.05). Our results suggest that older women can regain previous RT program benefits following detraining, regardless of the weekly training frequency. However, some fitness components may take longer to reestablish than the initial training level.

Impact of resistance exercise order on postexercise hemodynamic measures in middle-aged and older women

Abstract Aim: to compare the impact of different resistance exercise orders on postexercise hemodynamic measures in resistance-trained nonhypertensive middle-aged and older women. Methods: Twenty-three women (age 50-78 yrs) were randomized into two resistance training (RT) groups: one group started training sessions performing multi-joint exercises followed by single-joint exercises (MS, n = 12; 58.92 ± 5.53 yrs), while the other group performed their sessions in the opposite order (SM, n = 11; 57.93 ± 11.89 yrs). Both groups performed their RT sessions composed of 7 exercises performed in 3 sets of 10-15 repetitions maximum. Blood pressure was measured by automated equipment during pre-training and at 10, 20, 30, 40, 50, and 60 min after the training session. Results: Repeated-measures analysis of variance (ANOVA) identified an isolated effect of time only for systolic blood pressure (p = 0.003) with statistically significant reductions in pre-session measurement at 60 min post-session in both groups (MS: 117.67 ± 15.89 mmHg vs. 111.25 ± 11.84 mmHg and SM: 118.64 ± 15.13 mmHg vs. 111.50 ± 15.62 mmHg). Regarding diastolic blood pressure and subjective perception of effort, no difference was identified between groups (p > 0.05). Conclusion: We conclude that a RT session can promote post-exercise hypotension for systolic blood pressure after 60 min of recovery in middle-aged and nonhypertensive older women regardless of the exercise order.

Equating Resistance-Training Volume Between Programs Focused on Muscle Hypertrophy.

Calculating resistance-training volume in programs focused on muscle hypertrophy is an attempt to quantify the external workload carried out, then to estimate the dose of stimulus imposed on targeted muscles. The volume is usually expressed in some variables that directly affected the total training work, such as the number of sets, repetitions, and volume-load. These variables are used to try to quantify the training work easily, for the subsequent organization and prescription of training programs. One of the main uses of measures of volume quantification is seen in studies in which the purpose is to compare the effects of different training protocols on muscle growth in a volume-equated format. However, it seems that not all measures of volume are always appropriate for equating training protocols. In the current paper, it is discussed what training volume is and the potentials and shortcomings of each one of the most common ways to equate it between groups depending on the independent variable to be compared (e.g., weekly frequency, intensity of load, and advanced techniques).

Prediction of Anaerobic Power From Standing Long Jump in NCAA Division IA Football Players.

ABSTRACT: Mann, JB, Bird, M, Signorile, JF, Brechue, WF, and Mayhew, JL. Prediction of anaerobic power from standing long jump in NCAA Division IA football players. J Strength Cond Res 35(6): 1542-1546, 2021-Despite the popularity of the standing long jump (SLJ), limited research has explored the estimation of power developed during this test. The purpose of this study was to determine SLJ power from jump distance and selected anthropometric measures in NCAA Division IA football players. Height (Ht), body mass (Wt), thigh length, and lower leg length (LL) were measured in 58 players, allowing calculation of leg ratios of thigh length·Ht-1, LL·Ht-1, and TL·SL-1. Players performed 2-3 maximal familiarization trials of SLJ followed by 2 maximal jumps from a 3-dimension force plate sampling at 1,000 Hz. Standing long jump distance (intraclass correlation coefficient [ICC] = 0.944) and power (ICC = 0.926) calculated from resultant force and velocity vectors were highly reliable. Standing Ht (r = 0.40), Wt (r = 0.36), lower leg length (r = 0.43), total leg length (thigh + LLs) (r = 0.38), and best SLJ (r = 0.52) were significantly related (p < 0.05) to peak power, but none accounted for more than 27% of the common variance. Step-wise multiple regression identified SLJ and body mass as the only significant variables necessary to predict peak power (Power [W] = 32.49·SLJ [cm] + 39.69·Wt [kg] - 7,608, R = 0.86, SEE = 488 W, CV% = 9.3%). Standing long jump contributed 56.8% to the known variance, whereas Wt contributed 43.2%. Thus, a combination of SLJ and Wt can be used to effectively estimate explosive power in Division IA college football players.

Relationship of Barbell and Dumbbell Repetitions With One Repetition Maximum Bench Press in College Football Players.

ABSTRACT: Heinecke, ML, Mauldin, ML, Hunter, ML, Mann, JB, and Mayhew, JL. Relationship of barbell and dumbbell repetitions with one repetition maximum bench press in college football players. J Strength Cond Res 35(2S): S66-S71, 2021-Dumbbell training to augment barbell training is gaining popularity. However, information is lacking that details the compatibility of strength and endurance between dumbbell and barbell performances in the same exercise. Therefore, the purposes of this study were to compare the similarity of muscular endurance performance between dumbbell and barbell exercises and to assess the accuracy of predicting one repetition maximum (1RM) barbell bench press from barbell and dumbbell repetitions to fatigue (RTF). College football players (n = 40) performed 1RM barbell bench press and RTF with a 90.9-kg barbell. On separate days, unilateral (45.5 kg) and bilateral dumbbell (90.9 kg) RTF were performed. Barbell RTF (13.8 ± 9.2) were significantly greater (effect size [ES] = 0.14) than bilateral dumbbell RTF (12.5 ± 9.5) but highly correlated (r = 0.96). Unilateral dumbbell RTF were significantly greater (ES = 0.13) for dominant hand (10.8 ± 10.1) than nondominant hand (9.5 ± 9.7) but highly correlated (r = 0.97). Prediction of 1RM barbell bench press was equally effective using a constant weight barbell (r = 0.90) or equivalent weight bilateral dumbbells (r = 0.87) with total errors of 7.3 and 8.2%, respectively. Barbell and dumbbell repetitions with equivalent weights place a similar demand on the upper-body musculature for training and testing purposes in football athletes.

Comparision of Low and High Volume of Resistance Training on Body Fat and Blood Biomarkers in Untrained Older Women: A Randomized Clinical Trial.

ABSTRACT: Cunha, PM, Tomeleri, CM, Nascimento, MA, Mayhew, JL, Fungari, E, Cyrino, LT, Barbosa, DS, Venturini, D, and Cyrino, ES. Comparision of low and high volume of resistance training on body fat and blood biomarkers in untrained older women: a randomized clinical trial. J Strength Cond Res 35(1): 1-8, 2021-The purpose of this study was to compare the effects of resistance training (RT) performed with 2 different volumes on body fat and blood biomarkers in untrained older women. Sixty-five physically independent older women (≥60 years) were randomly assigned to one of 3 groups: low-volume (LV) training group, high-volume (HV) training group, and a control group. Both training groups performed RT for 12 weeks, using 8 exercises of 10-15 repetitions maximum for each exercise. The low-volume group performed only a single set per exercise, whereas the HV group performed 3 sets. Anthropometric, body fat (%), trunk fat, triglycerides (TG), total cholesterol, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol, very LDL-c (VLDL-c), glucose (GLU), C-reactive protein (CRP), and composite Z-score were measured. The HV group obtained greater improvements compared with the LV group (p < 0.05) for TG (LV = -10.5% vs. HV = -16.6%), VLDL-c (LV = -6.5% vs. HV = -14.8%), GLU (LV = -4.7% vs. HV = -11.1%), CRP (LV = -13.2% vs. HV = -30.8%), % body fat (LV = -2.4% vs. HV = -6.1%), and composite Z-score (LV = -0.13 ± 0.30 vs. HV = -0.57 ± 0.29). Trunk fat was reduced (p < 0.05) only in the HV group (-6.8%). We conclude that RT performed in higher volume seems to be the most appropriate strategy to reduce body fat (%), trunk fat, improve blood biomarkers, and reduce composite Z-score in older women.

Responsiveness to muscle mass gain following 12 and 24 weeks of resistance training in older women.

BACKGROUND: Many factors may influence the magnitude of individual responses to resistance training (RT). How the manipulation of training volume and frequency affects responsiveness level for muscle mass gain in older women has not been investigated. AIMS: This study had the objective of identifying responders (RP) and non-responders (N-RP) older women for skeletal muscle mass (SMM) gain from a 12-week resistance training (RT) program. Additionally, we analyzed whether the N-RP could gain SMM with an increase in weekly training volume over 12 additional weeks of training. METHODS: Thirty-nine older women (aged ≥ 60 years) completed 24 weeks of a whole-body RT intervention (eight exercises, 2-3×/week, 1-2 sets of 10-15 repetitions). SMM was estimated by DXA, and the responsive cut-off value was set at two times the standard error of measurement. Participants were considered as RP if they exceeded the cut-off value after a 12-week RT phase, while the N-RP were those who failed to reach the SMM cut-off. RESULTS: Of the 22 participants considered to be N-RP, only 3 accumulated SMM gains (P = 0.250) that exceeded the cut-off point for responsiveness following 12 additional weeks of training, while 19 maintained or presented negative SMM changes. Of the 17 participants considered to be RP, all continued to gain SMM after the second 12-week RT phase. No significant correlation was observed between the changes in SMM and any baseline aspect of the participants. CONCLUSIONS: Our results suggest that some older women are RP, while others are N-RP to SMM gains resulting from RT. Furthermore, the non-responsiveness condition was not altered by an increase of training volume and intervention duration while RP participants continue to increase SMM; it appears that RP continue to be RP, and N-RP continue to be N-RP.

Resistance training exercise selection: efficiency, safety and comfort analysis method / Seleção do exercício no treinamento resistido: método de análise eficiência, segurança e conforto

Abstract Manipulation of resistance training variables has been shown to have a substantial effect on muscular adaptations. A major variable in this process is exercise selection. In addition to the effectiveness of a given exercise to recruit the target muscle groups, safety considerations and individual comfort during execution of a lift should be considered. The correct biomechanics of the chosen exercise will assist in promoting desired muscle adaptations, while proper safety procedures will reduce risk of injury. Lifting comfort will facilitate enjoyment and foster adherence to the program. Therefore, the purpose of this paper was to offer guidelines for selection of resistance training exercises based on the Efficiency, Safety, and Comfort Analysis Method (ESCAM).

Resumo A manipulação das variáveis do treinamento resistido demonstraram ter um efeito substancial nas adaptações musculares. Uma variável importante neste processo é a seleção de exercícios. Além da eficácia de um determinado exercício para recrutar os grupos musculares-alvo, as considerações de segurança e conforto individual durante a execução de um levantamento devem ser considerados. A biomecânica correta do exercício escolhido ajudará a promover as adaptações musculares desejadas, enquanto os procedimentos de segurança adequados reduzirão o risco de lesões. O conforto no levantamento facilitará o prazer e promoverá a adesão ao programa. Portanto, o objetivo deste artigo é oferecer orientações para a seleção de exercícios no treinamento resistido com base no Método de Análise de Eficiência, Segurança e Conforto (ESCAM).

Placing Greater Torque at Shorter or Longer Muscle Lengths? Effects of Cable vs. Barbell Preacher Curl Training on Muscular Strength and Hypertrophy in Young Adults.

Muscular strength and hypertrophy following resistance training may be obtained in different degrees depending on the approach performed. This study was designed to compare the responses of the biceps brachii to two preacher curl exercises, one performed on a cable-pulley system (CAB; in which a greater torque was applied during the exercise when elbows were flexed and biceps shortened) and one performed with a barbell (BAR; in which greater torque was applied when the elbows were extended and biceps stretched). Thirty-five young adults (CAB: 13 men, 5 women; BAR: 12 men, 5 women; age = 24 ± 5 years) performed a resistance training program three times per week for 10 weeks, with preacher curl exercises performed in three sets of 8-12 repetitions. Outcomes measured included elbow flexion peak isokinetic torque at angles of 20°, 60°, and 100° (considering 0° as elbow extended), and biceps brachii thickness (B-mode ultrasound). Following the training period, there were significant increases for both groups in elbow flexion peak torque at the 20° (CAB: 30%; BAR = 39%; p = 0.046), 60° (CAB: 27%; BAR = 32%; p = 0.874), and 100° (CAB: 17%; BAR = 19%; p = 0.728), and biceps brachii thickness (CAB: 7%; BAR = 8%; p = 0.346). In conclusion, gains in muscular strength were greater for BAR only at longer muscle length, whereas hypertrophy was similar regardless of whether torque emphasis was carried out in the final (CAB) or initial (BAR) degrees of the range of motion of the preacher curl in young adults.

Comparison of the effects of different weekly frequencies of resistance training on metabolic health markers and body fat in older women.

BACKGROUND: The purpose of this study was to compare the effects of a 24-week resistance-training (RT) program performed 2 vs. 3 times per week on body fat and metabolic health markers in older women. METHODS: Thirty-nine women (≥60 years old) were randomly assigned to two groups according to RT frequency (G2x=two sessions per week, N.=19; and G3x=three sessions per week, N.=20) and were submitted to two 12-week stages of whole-body RT. In the first stage, participants performed 1 set of 10 to 15 repetitions in each of eight exercises, whereas in the second stage, they performed 2 sets of 10 to 15 repetitions. Body fat was estimated by DXA, while biochemical analyses were performed on venous blood samples collected in the morning hours after a 12 hours' fasting and after a minimum of 48 hours since the last physical exercise session. RESULTS: After the 24 weeks of RT, only G3x significantly reduced body fat mass (G2x=0.0%; G3x=-5.1%), whereas both G2x and G3x reduced blood glucose and C-reactive protein levels. Both groups improved HDL-C after the first 12-week stage compared to baseline, although the changes from pre- to post-training were not significantly different between groups. No significant difference was observed compared to baseline for total cholesterol, VLDL-C, LDL-C, and triglycerides for either group. CONCLUSIONS: These results suggest that RT-induced changes in health markers may occur regardless of RT frequency, whereas performing RT three times per week may be needed for reducing total body fat mass in older women.

Influence of Handgrip Stabilization During Isokinetic Knee Strength Assessment in Older Women.

The present study aimed to evaluate the influence of holding the chair handles during the assessment of older women's knee flexion and extension isokinetic and isometric strength. Of 57 older women (≥60 years) selected from a convenience sample for this research, 23 were randomly chosen to perform the tests twice for reliability analyses. Each participant performed maximal isokinetic knee extension and flexion at 60°/s and 180°/s angular velocities and isometric tests under two conditions: (a) holding the lateral handle of the chair (HOLD) and (b) supporting the hands on the shoulders with the arms crossed (i.e., not holding the handle [NHOLD]). Participants performed significantly better in the HOLD compared with the NHOLD condition. Slightly lower intraclass correlation coefficients (ICC = 0.870-0.956) were noted for the HOLD than for the NHOLD condition (ICC = 0.900-0.981) so that the HOLD performance on Days 1 and 2 was different on some measures. Owing to the higher reliability coefficients in the NHOLD condition, results suggest that, when assessing knee strength in older women, the evaluee should place their hands over their shoulders with arms crossed in front of the chest (NHOLD) to maximize assessment reliability (reproducibility of performance).

Agreement Between Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Track Changes in Fat-Free Mass After Resistance Training in Older Women.

Nascimento, MA, Silva, DRP, Ribeiro, AS, Pina, FLC, Gerage, AM, Gobbo, LA, Mayhew, JL, and Cyrino, ES. Agreement between bioelectrical impedance and dual-energy x-ray absorptiometry to track changes in fat-free mass after resistance training in older women. J Strength Cond Res 34(6): 1700-1708, 2020-The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10-15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM (F = 244.63, p < 0.001), although all equations had high correlations with DXA (r = 0.78-0.83). After training, 4 equations overpredicted and one underpredicted DXA FFM (F = 176.25, p < 0.001). Dual-energy X-ray absorptiometry detected significant gains in FFM (0.65 ± 0.82 kg; p < 0.05), as did EQ3 (0.55 ± 1.69 kg; p < 0.05), and EQ4 (0.61 ± 1.88 kg; p < 0.05), whereas the remaining equations did not indicate significant changes in FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.

Salivary stress hormone response and performance in full competition after linear or undulating periodization training in elite powerlifters.

BACKGROUND: The purposes of this study were to determine differences in training loads and stress hormones among national level powerlifting competitors and the effect on performance. METHODS: Thirteen experienced male powerlifters provided detailed training logs during the 8 weeks prior to a national competition. Participants were divided into linear (LP, N.=6) and undulating periodization (UP, N.=7) training groups. Following weigh-ins and after successfully completing the competition, participants provided saliva samples. RESULTS: LP resulted in lower levels of salivary cortisol (sC) (LP 4.27±0.71 nmols/L; UP 5.53±0.78 nmols/L) and higher testosterone-to-cortisol ratio (T:C) (LP 8.03±0.84 nmols/L; UP 5.23±1.41 nmols/L) compared to UP prior to competition. Following competition, both LP and UP groups had significant increases in salivary testosterone (sT) (LP 383.70±34.96 nmols/L; UP 376.62±38.17 nmols/L) and sC (LP 17.67±1.39 nmols/L; UP 18.17±1.46 nmols/L) and significant reductions in T:C (LP 8.03±0.80 to 6.67±0.83; UP 5.23±1.41 to 4.95±1.00). Finally, the UP group had a significantly higher Wilks coefficient following the competition compared to the LP group (LP 440.7±31.83 vs. UP 480.29±24.13). CONCLUSIONS: It appears that the higher volume loads undertaken by UP have a larger perturbation on resting stress hormones; however, this does not seem to negatively influence powerlifting performance.

Hydration status, sweating rate, heart rate and perceived exertion after running sessions in different relative humidity conditions: a randomized controlled trial

ABSTRACT The purpose of this study was to analyze the impact of running in normal relative humidity (RH = 53%) and very high RH (94%) on hydration status (HS), sweating rate (SR), heart rate (HR), and rating of perceived exertion (RPE). Fourteen men (25.2 ± 6.6 yrs) performed two sessions of treadmill running. Body mass (normal RH: -1.35%, very high RH: -1.65%) HS (normal RH: -14.8%; very high RH: -20.8%) were reduced while RPE (normal RH: +26%; very high RH: +28%) and HR were increased (very high RH: +5.8%: 20-40 min, +3.1%: 40-60 min, +3%: 20-40 min; +2.3%: 40-60 min for normal RH). As expected, SR was significantly greater during very high RH (-20/8%) compared to normal RH (-14.8%). Running in very high RH at moderate temperature has a greater negative impact on SR, HS, body mass, HR, RPE in men than running in normal RH at the same temperature, which places the runner in greater danger of heat illnesses such as heat exhaustion or heat stroke.

RESUMO Analisar o impacto da corrida em diferentes humidade relativa (HR) (normal (53%), muito alto (94%)), estado de hidratação (EH), taxa de transpiração (TT), freqüência cardíaca (FC), esforço percebido (RPE). Quatorze homens (25,2 anos) realizaram duas sessões de corrida em esteira. Massa corporal (HR normal: -1,35%, HR muito alta: -1,65%) e EH reduziram (HR normal: -14,8%, HR muito alta: -20,8%), RPE (HR normal: + 26%, HR muito alta: + 28%), aumento da FC (HR muito alta: + 5.8%: 20-40 min, + 3.1%: 40-60 min, HR normal: + 3%: 20-40 min; + 2.3%: 40-60 min). TT foi significantemente diferente entre HR (HR normal: -14.8%, HR muito alta: -20.8%). Há um impacto negativo na corrida em EH, massa corporal, FC e RPE em homens com HR normal e muito alta, e TT é mais afetada com HR muito alta.

RESUMEN El objetivo de este estudio fue analizar las repercusiones de correr con diferentes niveles de humedad relativa (HR) (normal [53%], muy alta [94%]) sobre el estado de hidratación (EH), la tasa de sudoración (TS), la frecuencia cardíaca (FC) y el esfuerzo percibido (EP). Catorce hombres (25,2 ± 6,6 años) realizaron dos sesiones en cinta de correr. La masa corporal (HR normal: -1,35%; HR muy alta: -1,65%) y el EH (HR normal: -14,8%; HR muy alta: -20,8%) se redujeron, mientras que el EP (HR normal: +26%; HR muy alta: +28%) y la FC (HR muy alta: +5,8%: 20-40 min; +3,1%: 40-60 min; HR normal: + 3%: 20-40 min; + 2,3%: 40-60) aumentaron. La TS fue considerablemente diferente entre las HR (HR normal: -14,8%; muy alta HR: -20,8%). Hay repercusiones negativas por correr con una HR muy alta y una temperatura moderada en TS, EH, masa corporal, FC y EP en corredores que corren a una HR normal a la misma temperatura, lo que sitúa a estos en gran peligro de sufrir un enfermedad provocada por el calor, como agotamiento por calor o golpe de calor.