Resistance-trained Women Research Articles

Impact of CYP1A2 Genotypes on the Ergogenic Effects and Subjective Mood States of Caffeine Ingestion in Resistance-Trained Women.

Caffeine's metabolism is determined by CYP1A2 genotypes: AC/CC (SLOW) and AA (FAST). This trial evaluated CYP1A2 genotypes' impact on exercise and cognitive effects in 36 resistance-trained females assessed under placebo (PL) and caffeine (6 mg/kg bw anhydrous caffeine-CAF) conditions, before ingestion and throughout the session. 23andMe® (San Francisco, CA, USA) determined genotypes using saliva. Data were analyzed using two-way RMANOVA and paired-samples t-tests (p < 0.05). A significant main effect for genotype existed for leg press repetitions to failure (RTF) for CAF (p = 0.038), with the FAST group performing more repetitions than the SLOW (p = 0.027). There was a significant condition x genotype interaction for the subjective outcome index score (p = 0.045), with significant differences for time (p < 0.01) and between genotype (p < 0.001). Follow-up analysis revealed a higher total score (p = 0.028) following CAF for the FAST group and a lower total score (p < 0.01) in the SLOW group. Dizziness was reported following CAF in the SLOW group (p = 0.014; Cohen's d = 0.725). Aside from leg press RTF, subjective outcome index score, and dizziness, the genotype groups experienced similar responses to resistance exercise performance and subjective mood states following caffeine ingestion.

Multi-Ingredient Preworkout Supplementation Compared With Caffeine and a Placebo Does Not Improve Repetitions to Failure in Resistance-Trained Women.

To determine the effect of varying doses of MIPS compared with caffeine only (C) and a placebo (PL) on resistance-training performance in trained women. Ten women (21.5 [2.3]y) completed 1-repetition-maximum tests at baseline for leg press and bench press. A within-group, double-blind, and randomized design was used to assign supplement drinks (ie,PL, C, MIPS half scoop [MIPS-H], and MIPS full scoop [MIPS-F]). Repetitions to failure were assessed at 75% and 80% to 85% of 1-repetition maximum for bench and leg press, respectively. Total performance volume was calculated as load × sets × repetitions for each session. Data were analyzed using a 1-way repeated-measures analysis of variance and reported as means and SDs. There were no differences in repetitions to failure for bench press (PL: 14.4 [3.2] repetitions, C: 14.4 [2.9] repetitions, MIPS-H: 14.2 [2.6] repetitions, MIPS-F: 15.1 [3.1] repetitions; P = .54) or leg press (PL: 13.9 [7.8] repetitions, C: 10.8 [5.9] repetitions, MIPS-H: 13.1 [7.1] repetitions, MIPS-F: 12.4 [10.7] repetitions; P = .44). Furthermore, there were no differences in total performance volume across supplements for bench press (PL: 911.2 [212.8]kg, C: 910.7 [205.5]kg, MIPS-H: 913.6 [249.3]kg, MIPS-F: 951.6 [289.6]kg; P = .39) or leg press (PL: 4318.4 [1633.6]kg, C: 3730.0 [1032.5]kg, MIPS-H: 4223.0 [1630.0]kg, MIPS-F: 4085.5 [2098.3]kg; P = .34). Overall, our findings suggest that caffeine and MIPS do not provide ergogenic benefits for resistance-trained women in delaying muscular failure.

Skeletal Muscle Compliance and Echogenicity in Resistance-Trained and Nontrained Women.

Mongold, SJ, Ricci, AW, Hahn, ME, and Callahan, DM. Skeletal muscle compliance and echogenicity in resistance-trained and nontrained women. J Strength Cond Res 38(4): 671-680, 2024-Noninvasive assessment of muscle mechanical properties in clinical and performance settings tends to rely on manual palpation and emphasizes examination of musculotendinous stiffness. However, measurement standards are highly subjective. The purpose of the study was to compare musculotendinous stiffness in adult women with varying resistance training history while exploring the use of multiple tissue compliance measures. We identified relationships between tissue stiffness and morphology, and tested the hypothesis that combining objective measures of morphology and stiffness would better predict indices of contractile performance. Resistance-trained (RT) women (n = 11) and nontrained (NT) women (n = 10) participated in the study. Muscle echogenicity and morphology were measured using B-mode ultrasonography (US). Vastus lateralis (VL) and patellar tendon (PT) stiffness were measured using digital palpation and US across submaximal isometric contractions. Muscle function was evaluated during maximal voluntary isometric contraction (MVIC) of the knee extensors (KEs). Resistance trained had significantly greater PT stiffness and reduced echogenicity (p < 0.01). Resistance trained also had greater strength per body mass (p < 0.05). Muscle echogenicity was strongly associated with strength and rate of torque development (RTD). Patellar tendon passive stiffness was associated with RTD normalized to MVIC (RTDrel; r = 0.44, p < 0.05). Patellar tendon stiffness was greater in RT young women. No predictive models of muscle function incorporated both stiffness and echogenicity. Because RTDrel is a clinically relevant measure of rehabilitation in athletes and can be predicted by digital palpation, this might represent a practical and objective measure in settings where RTD may not be easy to measure directly.

Efficacy of progressive versus severe energy restriction on body composition and strength in concurrent trained women

PurposeThis study evaluated the concurrent training (CT) effect in combination with either progressive energy restriction (PER) or severe energy restriction (SER) on body composition and strength-related variables in resistance-trained women.MethodsFourteen women (29.5 ± 3.8 years; 23.8 ± 2.8 kg·m−2) were randomly assigned to a PER (n = 7) or SER (n = 7) group. Participants performed an 8-week CT program. Pre- and post-intervention measures of fat mass (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry and strength-related variables were assessed through 1-repetition maximum (in the squat and bench press) and countermovement jump.ResultsSignificant reductions in FM were observed in PER and SER (Δ = − 1.7 ± 0.4 kg; P = < 0.001; ES = − 0.39 and Δ = − 1.2 ± 0.6 kg; P = 0.002; ES = − 0.20, respectively). After correcting FFM for fat-free adipose tissue (FFAT), no significant differences for this variable were found either in PER (Δ = − 0.3 ± 0.1; P = 0.071; ES = − 0.06) or in SER (Δ = − 0.2 ± 0.1; P = 0.578; ES = − 0.04). There were no significant changes in the strength-related variables. No between-group differences were found in any of the variables.ConclusionA PER has similar effects to a SER on body composition and strength in resistance-trained women performing a CT program. Given that PER is more flexible and thus may enhance dietary adherence, it might be a better alternative for FM reduction compared to SER.

Propulsion Phase Characteristics of Loaded Jump Variations in Resistance-Trained Women

The purpose of this study was to compare the propulsion phase characteristics of the jump squat (JS), hexagonal barbell jump (HEXJ), and jump shrug (JShrug) performed across a spectrum of relative loads. Thirteen resistance-trained women (18-23 years old) performed JS, HEXJ, and JShrug repetitions at body mass (BM) or with 20, 40, 60, 80, or 100% BM during three separate testing sessions. Propulsion mean force (MF), duration (Dur), peak power output (PP), force at PP (FPP), and velocity at PP (VPP) were compared between exercises and loads using a series of 3 × 6 repeated measures ANOVA and Hedge's g effect sizes. There were no significant differences in MF or Dur between exercises. While load-averaged HEXJ and JShrug PP were significantly greater than the JS, there were no significant differences between exercises at any individual load. The JShrug produced significantly greater FPP than the JS and HEXJ at loads ranging from BM-60% BM, but not at 80 or 100% BM. Load-averaged VPP produced during the JS and HEXJ was significantly greater than the JShrug; however, there were no significant differences between exercises at any individual load. Practically meaningful differences between exercises indicated that the JShrug produced greater magnitudes of force during shorter durations compared to the JS and HEXJ at light loads (BM-40%). The JS and HEXJ may be classified as more velocity-dominant exercises while the JShrug may be more force-dominant. Thus, it is important to consider the context in which each exercise is prescribed for resistance-trained women to provide an effective training stimulus.

Photobiomodulation therapy with light-emitting diode does not improve lower-body muscle performance and delayed-onset muscle soreness in resistance-trained women: A randomized, controlled, crossover trial

Photobiomodulation (PBM) with light-emitting diode therapy (LEDT) are among the most common strategy for improving performance and recovery from physical exercise in young adults. However, its effectiveness in resistance-trained women remains contradictory. The purpose of this study was to investigate the effects of light-emitting diode therapy (LEDT) at 940 nm on lower-body muscle performance, rating of perceived exertion (RPE), and delayed-onset muscle soreness (DOMS) in resistance-trained women. Ten young women (20.4 ± 3.3 years) participated in a crossover study in which they received, in a counterbalanced manner, active and placebo LEDT on two occasions (T1 and T2), separated by a 7-day washout period. LEDT (130 mW output power, power density of 45 mW.cm −2 , and total energy of 48 J per leg) was applied on the quadriceps muscle immediately before the repetitions-to-failure test (6 sets at 80% of 1RM until failure) for leg press exercise. Maximum number of repetitions and RPE over the 6 sets, and DOMS at 24 and 48 hours after fatigue test were recorded. There was a significant (time P < 0.05) reduction in the maximum number of repetitions and a reciprocal increase in RPE over the 6 sets, with no statistical differences (treatment × time P > 0.05) between placebo and active LEDT conditions. DOMS increased from 24 to 48 hours after fatigue test in both conditions (time P < 0.05; treatment × time P > 0.05). Our results indicate that acute LEDT at 940 nm does not improve lower-body muscle performance, RPE, and DOMS in resistance-trained women. La photobiomodulation (PBM) avec thérapie par diodes électroluminescentes (LEDT) est l’une des stratégies les plus courantes pour améliorer les performances et la récupération après l’exercice physique chez les jeunes adultes. Cependant, son efficacité chez les femmes entraînées à la résistance reste contradictoire. Le but de cette étude était d’étudier les effets de la thérapie par diodes électroluminescentes (LEDT) à 940 nm sur les performances musculaires du bas du corps, l’évaluation de l’effort perçu (RPE) et les douleurs musculaires d’apparition retardée (DOMS) chez les femmes entraînées à la résistance. Dix jeunes femmes (20,4 ± 3,3 ans) ont participé à une étude croisée dans laquelle elles ont reçu, de manière contrebalancée, une LEDT active et placebo à deux reprises (T1 et T2), séparées par une période de sevrage de 7 jours. LEDT (puissance de sortie de 130 mW, densité de puissance de 45 mW.cm −2 , et énergie totale de 48 J par jambe) a été appliquée sur le muscle quadriceps immédiatement avant le test de répétitions à l’échec (6 séries à 80 % de 1RM jusqu’à échec) pour l’exercice de presse des jambes. Le nombre maximum de répétitions et de RPE sur les 6 séries, et DOMS à 24 et 48 heures après le test de fatigue ont été enregistrés. Il y a eu une réduction significative (temps p < 0,05) du nombre maximal de répétitions et une augmentation réciproque de l’EPR sur les 6 séries, sans différence statistique (traitement × temps p > 0,05) entre les conditions placebo et LEDT actives. DOMS a augmenté de 24 à 48 heures après le test de fatigue dans les deux conditions (temps p < 0,05 ; temps de traitement × temps p > 0,05). Nos résultats indiquent que la LEDT aiguë à 940 nm n’améliore pas les performances musculaires du bas du corps, l’EPR et les DOMS chez les femmes entraînées en résistance.

Creatine Supplementation Improves Muscular Performance without Additional Impact on the Cardiovascular System in Trained Women

Creatine monohydrate supplementation in females is largely under-represented in the literature, and their potentially differential hemodynamic responses are unknown. Methods: Twenty-eight resistance-trained women (25.5 ± 6.1 years, 59.7 ± 6.3 kg, 163 ± 5 cm) were randomly assigned to the supplement creatine monohydrate (CRE; 5 g creatine monohydrate + 5 g dextrose) or placebo (PLA; 10 g dextrose) four times per day for 7 days in a double-blind fashion. Each subject subsequently completed resistance training sessions (3 × week) for four weeks with four sets to muscular failure of both half-squat and leg press exercises. The change in body mass (BM), exercise repetition number (REP), rated perceived exertion (RPE), and cardiovascular variables were assessed (sessions 1, 6, and 12). Statistical analyses were performed at a significance level of p ≤ 0.05. Results: Analyses revealed a significant CRE-specific BM increase (p = 0.013), as well as significantly greater half-squat (p = 0.006) and leg press (p = 0.017) REP per set versus PLA. Additionally, CRE demonstrated significantly lower relative RPE values at session 12 compared with previous sessions. Any significant main or interaction effects were observed for the studied cardiovascular variable. Conclusions: The present data substantiate the creatine’s efficacy to improve muscular performance in females while demonstrating the safety of combined creatine monohydrate supplementation and resistance training on cardiovascular parameters.

Load–Velocity Relationship to Estimate the One-Repetition Maximum in the Hexagonal Bar Deadlift Exercise in Women

In this study, we examined the load–velocity relationship in the hexagonal bar deadlift exercise in women. Twenty-seven resistance-trained women were recruited. Participants performed a progressive load test up to the one-repetition maximum (1RM) load for determining the individual load–velocity relationship in the hexagonal bar deadlift exercise. Bar velocity was measured in every repetition through a linear encoder. A very strong and negative relationship was found between the %1RM and bar velocity for the linear (R2 = .94; standard error of the estimation = 5.43% 1RM) and second-order polynomial (R2 = .95) regression models. The individual load–velocity relationship provided even better adjustments (R2 = .98; coefficient of variation = 1.77%) than the general equation. High agreement level and low bias were found between actual and predicted 1RM for the general load–velocity relationship (intraclass correlation coefficient = .97 and 95% confidence interval [0.90, 0.99]; bias = −2.59 kg). In conclusion, bar velocity can be used to predict 1RM with high accuracy during hexagonal bar deadlift exercise in resistance-trained women.

Effects of one long vs. two short resistance training sessions on training volume and affective responses in resistance-trained women.

The aim of this study was to compare the acute effects of performing a lower body resistance training program in one long or two shorter sessions in 1 day on training volume and affective measures. Employing a randomized-crossover design, 23 resistance-trained women (22 ± 2 years, 166 ± 6 cm, and 66.4 ± 7.5 kg) performed two training days consisting of (i) one long (46 min) or (ii) two short sessions (total of 43 min) separated by 3.5–5 h. Each training day was separated by 4-6 days and consisted of three sets to failure for six exercises. Training volume (number of repetitions lifted) were recorded during the sessions. Rating of perceived exertion for effort (RPE), rating of perceived exertion for discomfort (RPD), session displeasure/pleasure (sPDF) and exercise enjoyment (EES) were measured 10 min after each session. Participants also completed a readiness to train questionnaire (7 questions), 24 h after each session, and which training protocol they preferred, 48 h after the last session. The long session led to higher RPE (+1 point, p < 0.001, ES = 1.07), RPD (+1 point, p = 0.043, ES = 0.53) and sPDF (p = 0.010, ES = 0.59) compared to the short sessions. There was no difference in EES (p = 0.118, ES = 0.33). The short sessions had 3% higher training volume than the long session (p = 0.002, ES = 0.42). There were no differences in perceived readiness to train 24 h after the sessions (range: p = 0.166–0.856 and ES = 0.08–0.32). Twenty-two participants preferred the long session, while one preferred the short sessions. In conclusion, performing a longer, lower body, resistance training session led to greater perceptions of effort, discomfort and session pleasure than splitting the same program into two shorter sessions among resistance-trained women. However, two shorter sessions led to a greater training volume.

Manual myofascial release and muscle energy enhances trunk flexibility and strength in recreationally resistance-trained women: Cross-over study

The purpose of this study was to compare the effects of myofascial release and muscle energy on acute outcomes in trunk extensors active range-of-motion and strength in recreationally resistance-trained women. Seventeen apparently healthy women performed three experimental protocols using a cross-over, randomized (counterbalanced in Latin Square format), and within-subjects design: a) range-of-motion and strength test after a manual myofascial release protocol (MFR); b) flexibility and strength test after a muscle energy protocol (ME); and c) range-of-motion and strength test without myofascial release or muscle energy (control condition). Active trunk range-of-motion was measured via a sit-and-reach test and trunk extension strength via isometric dorsal dynamometer. A significant increase in range-of-motion was found for MFR (p = 0.002; d = 0.71) and ME (p < 0.001; d = 0.47) when comparing post-intervention with baseline values. Similarly, a significant increase for strength was found for MFR (p = 0.018; d = 0.10) when comparing post-intervention with baseline values. In conclusion, both techniques (MFR and ME) improved trunk range-of-motion with the sit and reach test immediately post-intervention; however, MFR showed greater magnitude increases in range-of-motion (MFR: (medium magnitude) vs ME: small magnitude). Due to the potential health implications, both (MFR and ME) responses should be among the many considerations for rehabilitation and performance exercise prescription when prescribing an exercise regimen.

Resistance Exercise Alone Or In Conjunction With Caffeine On Measures Of Left Ventricular Workload In Women

Resistance exercise alone or in conjunction with caffeine increases heart rate and blood pressure in resistance-trained women. While acute resistance exercise has been shown to increase measures of left ventricular workload, the addition of caffeine on these responses is unknown. PURPOSE: To evaluate alterations in left ventricular workload at rest, following acute caffeine supplementation or placebo, as well as during recovery from a fatiguing bout of resistance exercise in resistance-trained women. METHODS: Eleven resistance-trained women (Mean ± SD: Age: 24 ± 4 yrs) participated in a counterbalanced, double blind, placebo-controlled, crossover-design study. Each participant drank 4 mg/kg of caffeine mixed with water. Applanation tonometry was used to measure left ventricular workload at rest (Rest1), 45 minutes after caffeine ingestion (Rest2), immediately post-resistance exercise (Post 1), and 10 minutes post-resistance exercise (Post2). The acute bout of resistance exercise consisted of two sets at 75% 1-repetition maximum (1RM) for 10 repetitions, and one set at 70%1RM with repetitions to failure on the squat and bench press. Two minutes of rest were given between sets and exercises. A 2x4 two-way analysis of variance (ANOVA) was used to assess the effects of condition with a repeated measure of time. RESULTS: There were significant main effects of time for wasted left ventricular energy (Rest1: 608 ± 687dynes*s/cm2; Rest2: 529 ± 667dynes*s/cm2; Post1: 2154 ± 1164dynes*s/cm2; Post2: 1956 ± 1873dynes*s/cm2, p = 0.003), systolic pressure time index (Rest1: 1900 ± 290 mmHg*s; Rest2: 1937 ± 390 mmHg*s; Post1: 2769 ± 535 mmHg*s; Post2: 2652 ± 512 mmHg*s, p = 0.001), diastolic pressure time index (Rest1: 2827 ± 244 mmHg*s; Rest2: 2973 ± 294 mmHg*s; Post1: 2349 ± 319 mmHg*s; Post2: 2289 ± 402 mmHg*s, p = 0.001), and the subendocardial viability ratio (Rest1: 154 ± 34%; Rest2: 163 ± 44%; Post1: 90 ± 31%; Post2: 92 ± 33%, p = 0.001). While there were no significant differences from Rest1 to Rest2, there were significant increases for each of these variables such that Post1 and Post2 were augmented above Rest1 and Rest2. CONCLUSION: These data suggest that resistance exercise in conjunction with 4 mg/kg of caffeine does not mediate additional left ventricular workload compared to a placebo in resistance-trained women.

Association Between Obstetric History and Urinary Incontinence in a Cohort of Resistance-Trained Women

PurposeUrinary incontinence has the potential to reduce participation in sport and exercise and diminish athletic performance. The purpose of this study was to explore the association between obstetric history and urinary incontinence in a cohort of resistance-trained women.Patients and MethodsThis international, cross-sectional survey was completed by 1252 women competing in either powerlifting, weightlifting or CrossFit. The Incontinence Severity Index determined the severity of urinary incontinence.ResultsAlmost 43% of the participants experienced urinary incontinence in the threemonths prior to the study. The prevalence of urinary incontinence in this cohort according to mode of birth were: caesarean 42.6%, unassisted vaginal 59.3%, vacuum extraction 58.8%, forceps 60.3%, vaginal and caesarean births 66.2%, forceps and vacuum extraction 73.1%. The prevalence of urinary incontinence in the subgroup of women who had undergone urogenital surgery was 63.6%. Kendall’s tau-b indicated that the correlation between ISI score and the number of births was strong and positive (τ = 0.25, p < 0.001).ConclusionOur results suggest that both the number of births and mode of birth influenced the likelihood of urinary incontinence in resistance-trained women. Women who had experienced only caesarean births had the lowest likelihood of urinary incontinence, while women who had experienced both vaginal and caesarean births had the most severe and second highest likelihood of urinary incontinence. Women who had undergone urogenital surgery continued to experience a high likelihood of urinary incontinence.

Effects Of A Vibrating Foam Roller On The Work Of The Quadriceps And Hamstrings

PURPOSE: The purpose of this study was to compare the effects of a vibrating foam roller, a foam roller, and vibration-only on the dominant hamstrings, with a secondary aim of examining the effects on the quadriceps and non-dominant limb. METHODS: Fifteen resistance trained women (mean age ± SD = 22.9 ± 2.0 years, height = 162.7 ± 4.8 cm, body mass = 66.0 ± 9.7 kgs, BMI = 24.9 ± 3.3 kg·m2) completed 4 testing sessions consisting of a foam rolling, a vibrating foam rolling, a vibration-only, and a control condition, to compare their effects on the work of the quadriceps and hamstrings. Conditions were only implemented on the participant’s dominant hamstrings, while testing was performed on both of the participant’s limbs to investigate possible contralateral effects. Participants completed concentric dynamometer testing at 60°s·-1, 180°s·-1, and 300°s·-1 for hamstrings and quadriceps, and eccentric dynamometer testing at 60°s·-1 and 180°s·-1 on the hamstrings. RESULTS: For concentric hamstrings, the treated dominant limb decreased pre- to-post testing (p = 0.004), while the non-dominant untreated limb decreased only during the vibrating foam rolling condition at the 180°s·-1 velocity (p = 0.036). The work of the concentric hamstrings of both limbs also decreased as velocity increased (p < 0.001) and decreased pre- to-post testing (p = 0.004). For the eccentric hamstrings, the dominant treated limb decreased pre- to post-testing (p = 0.001). The work of the eccentric hamstrings of both limbs decreased as velocity increased (p = 0.005) and decreased pre- to-post testing (p = 0.009). For concentric quadriceps, the work of the treated dominant limb was greater than the non-dominant untreated limb (p = 0.011), and the treated dominant limb decreased pre- to-post testing, while the non-dominant untreated limb increased (p = 0.009). The work of the concentric quadriceps of both limbs also decreased as velocity increased (p < 0.001). CONCLUSIONS: Since it is possible vibrating foam rolling, foam rolling, and vibration-only could decrease the work of the limb, is recommended to avoid using these interventions prior to a training session.

Caffeine ingestion attenuates diurnal variation of lower-body ballistic performance in resistance-trained women

ABSTRACT The present study investigates the effect of an acute intake of caffeine on the diurnal variation of neuromuscular performance in resistance-trained women. A total of 15 resistance-trained women participated in the current triple-blind, placebo-controlled, crossover experimental study. We assessed neuromuscular performance (i.e. ballistic (countermovement jump [CMJ] height and bench press throw [BPT] peak velocity), maximal strength (squat and bench press [BP] one-repetition maximum [1RM]), and strength-endurance [average velocity of the set during squat and number of repetitions-to-failure in BP]) four times at within 7 days. The participants ingested an acute dose of caffeine (3 mg/kg) or a placebo at 9–11 am and/or 17–19 pm. CMJ height (P = .016) and BP peak velocity (P = .012) were higher in the afternoon than in the morning. Compared to placebo, caffeine intake increased CMJ height by 3.1% in the morning and 1.6% in the afternoon (P = .035), but it had no effect on BPT peak velocity (P = .381). Maximal strength and strength-endurance performances were not affected by the time-of-day or caffeine intake (all P > .3). No significant interaction (time-of-day x substance) was observed in any of the above-mentioned outcomes (all P > .1). In conclusion, an acute dose of caffeine in the morning was effective to restore CMJ performance to levels found in the afternoon, while this effect was not observed neither in BPTpeak velocity nor in lower- and upper-body maximal strength and strength-endurance performance. Moreover, lower- and upper-body ballistic performance were greater in the afternoon than in the morning in resistance-trained women, while the acute intake of caffeine was only effective to increase CMJ height. Highlights Ballistic performance is probably higher in the afternoon than in the morning in resistance-trained women. An acute intake of caffeine is effective to increase countermovement jump performance. The ingestion of an acute dose of caffeine in the morning restored countermovement jump performance to levels found in the afternoon.

A randomized-controlled trial comparing supervised aerobic training to resistance training followed by unsupervised exercise on physical functioning in older breast cancer survivors

IntroductionThis study compared the relative efficacy of aerobic training to resistance training on physical functioning in older breast cancer survivors and determined whether benefits could be maintained by transitioning to unsupervised home-based training. Materials and methodsEarly-stage, post-treatment, older (≥65 years) breast cancer survivors (n = 114; mean age 72 years) were randomized to 12 months of supervised aerobic (n = 37), resistance (n = 39) or stretching (active control; n = 38) training followed by 6 months of unsupervised home-based training. Outcomes included aerobic capacity by 6-min walk distance (6MWD; m), maximal upper and lower body strength (1-repetition maximum; kg); physical function by short physical performance battery (SPPB), SF-36 and Late Life Function and Disability Instruments. ResultsOver 12-months of supervised exercise, all groups improved in muscle strength and SPPB scores, but resistance trained women also improved 6MWD. Improvements in upper and lower body strength in the resistance group were significantly greater than those in the stretching control (+2.5 kg vs. +1.8 kg; p = 0.05) and aerobic groups (+8.3 kg vs +2.7 kg; p = 0.047), respectively, with trends for greater improvements in 6MWD (+57.9 m vs. +22.5 m; p = 0.057) and self-report physical function (+4.8 vs. -4.4; 0.066) in resistance trained women versus controls. Compared to values at 12 months, there were no changes during unsupervised training in any measure within or between groups, except for self-reported advanced lower extremity function which improved in the resistance group and fell in the aerobic group (+1.3 vs. -3.1; p = 0.043). DiscussionSupervised exercise can improve strength and physical functioning among older breast cancer survivors. Resistance training may lead to better improvements compared to aerobic or flexibility training, whether in a supervised or unsupervised setting.Clinicaltrials.govNCT00662103

The relationship between y balance performance and hip strength in recreationally trained women

This study set one´s sight on the relationship between lower quarter y balance test (YBT-LQ) score with hip isometric strength with recreationally resistance-trained women. Utilizing dynamic balance as a screening tool for lower extremity injury risk has been proposed as a potential solution in injury prevention and injury assessment. A convenience sample of twenty young college females (22.3 ± 2.1 years) with a background in regular strength or plyometric training volunteered to participate in this study. The scores of YBT-LQ for each direction were calculated. A hand-held dynamometer was used to measure the maximum voluntary isometric strength of each participant´s unilateral hip extensors, flexors, adductors, abductors, internal and external rotation muscles. Significant lower normalized score was noted for the dominant limb (81.2 ± 11.7) when compared to non-dominant limb (83.6 ± 12.4) for anterior distance. For the composite score of YBT-LQ, a weak association was noted for hip extension and internal rotation, and moderate association was observed for hip flexion, adduction, and abduction. On the other hand, a strong association was observed between hip external rotators strength (r =0.516). Thus, the main finding of the current study was the strong association observed between hip external rotators strength and composite score of YBT-LQ.

Hormonal stress responses of growth hormone and insulin-like growth factor-I in highly resistance trained women and men

The purpose of this study was to examine the responses of growth hormone (GH) and insulin-like growth factor-I (IGFI) to intense heavy resistance exercise in highly trained men and women to determine what sex-dependent responses may exist. Subjects were highly resistance trained men (N = 8, Mean ± SD; age, yrs., 21 ± 1, height, cm, 175.3 ± 6.7, body mass, kg, 87.0 ± 18.5, % body fat, 15.2 ± 5.4, squat X body mass, 2.1 ± 0.4; and women (N = 7; Mean ± SD, age, yrs. 24 ± 5, height, cm 164.6 ± 6.7, body mass, kg 76.4 ± 8.8, % body fat, 26.9 ± 5.3, squat X body mass, 1.7 ± 0.6). An acute resistance exercise test protocol (ARET) consisted of 6 sets of 10 repetitions at 80% of the 1 RM with 2 min rest between sets was used as the stressor. Blood samples were obtained pre-exercise, after 3 sets, and then immediately after exercise (IP), 5, 15, 30, and 70 min post-exercise for determination of blood lactate (HLa), and plasma glucose, insulin, cortisol, and GH. Determination of plasma concentrations of IGFI, IGF binding proteins 1, 2, and 3 along with molecular weight isoform factions were determined at pre, IP and 70 min. GH significantly (P ≤ 0.05) increased at all time points with resting concentrations significantly higher in women. Significant increases were observed for HLa, glucose, insulin, and cortisol with exercise and into recovery with no sex-dependent observations. Women showed IGF-I values that were higher than men at all times points with both seeing exercise increases. IGFBP-1 and 2 showed increase with exercise with no sex-dependent differences. IGFBP-3 concentrations were higher in women at all-time points with no exercise induced changes. Both women and men saw an exercise induced increase with significantly higher values in GH in only the mid-range (30-60 kD) isoform. Only women saw an exercise induced increase with significantly higher values for IGF fractions only in the mid-range (30–60 kD) isoform, which were significantly greater than the men at the IP and 70 min post-exercise time points. In conclusion, the salient findings of this investigation were that in highly resistance trained men and women, sexual dimorphisms exist but appear different from our prior work in untrained men and women and appear to support a sexual dimorphism related to compensatory aspects in women for anabolic mediating mechanisms in cellular interactions.

Effects of a low-carbohydrate ketogenic diet on health parameters in resistance-trained women.

The aim of this study was to evaluate the effect of a ketogenic diet on blood pressure, visceral adipose tissue (VAT), bone mineral content (BMC), and bone mineral density (BMD) in trained women. Twenty-one resistance-trained women performed an 8-week resistance training program after a 3-week familiarization phase. Participants were randomly assigned to a non-ketogenic diet (n = 11, NKD) or ketogenic diet (n = 10, KD) group. Health parameters were measured before and after the nutritional intervention. Blood pressure was measured using a digital automatic monitor, while VAT, BMC, and BMD changes were measured by dual-energy X-ray absorptiometry. There was a significant reduction in systolic blood pressure in KD (mean ± SD [IC 95%], P value, Hedges' g; - 6.3 ± 6.0 [- 10.5, - 2.0] mmHg, P = 0.009, g = - 0.81) but not in NKD (- 0.4 ± 8.9 [- 6.8, 6.0] mmHg, P = 0.890, g = - 0.04). The results on VAT showed no changes in both groups. The KD showed a small favorable effect on BMD (0.02 ± 0.02 [0.01, 0.03] g·cm-2, P = 0.014, g = 0.19) while NKD did not show significant changes (0.00 ± 0.02 [- 0.02, 0.02] g·cm-2, P = 0.886, g = 0.01). No differences in group or in the time × group interaction were found in any of the variables. Consuming a low-carbohydrate high-fat KD in conjunction with a resistance training program might help to promote the improvement of health-related markers in resistance-trained women. Long-term studies are required to evaluate the superiority of a KD in comparison to a traditional diet.

Effects of the Menstrual Cycle on Jumping, Sprinting and Force-Velocity Profiling in Resistance-Trained Women: A Preliminary Study.

The aim of this study was to examine the effects of the menstrual cycle on vertical jumping, sprint performance and force-velocity profiling in resistance-trained women. A group of resistance-trained eumenorrheic women (n = 9) were tested in three phases over the menstrual cycle: bleeding phase, follicular phase, and luteal phase (i.e., days 1–3, 7–10, and 19–21 of the cycle, respectively). Each testing phase consisted of a battery of jumping tests (i.e., squat jump [SJ], countermovement jump [CMJ], drop jump from a 30 cm box [DJ30], and the reactive strength index) and 30 m sprint running test. Two different applications for smartphone (My Jump 2 and My Sprint) were used to record the jumping and sprinting trials, respectively, at high speed (240 fps). The repeated measures ANOVA reported no significant differences (p ≥ 0.05, ES < 0.25) in CMJ, DJ30, reactive strength index and sprint times between the different phases of the menstrual cycle. A greater SJ height performance was observed during the follicular phase compared to the bleeding phase (p = 0.033, ES = −0.22). No differences (p ≥ 0.05, ES < 0.45) were found in the CMJ and sprint force-velocity profile over the different phases of the menstrual cycle. Vertical jump, sprint performance and the force-velocity profiling remain constant in trained women, regardless of the phase of the menstrual cycle.

Effect of rest period configurations on systemic inflammatory response in resistance-trained women

ABSTRACT This investigation examined the effect of rest- redistribution (RR) on the circulating cytokine response to resistance exercise in resistance- trained women. Participants (n = 13; 24 ± 4y; 65.0 ± 10.6 kg; 160.5 ± 5.1 cm) completed two sessions of back squats at 70% of 1- repetition maximum: Traditional sets (TS: 4x10, 120-s inter- set rest) and RR (4x 2x5) with 30-s intra- set rest after 5 repetitions and 90-s inter- set rest. Serum creatine kinase (CK), IL-1β, IL-6, IL-8, IL-10, IL-15, and IL-6/IL-10 were determined before (PRE), immediately- post (IP), and 5, 15, 30, 60 min, 24 h, and 48 h post- exercise. CK increased significantly (p < 0.05) from PRE through 24 h for TS and through 48 h for RR. IL-15 was greater for RR than TS at 48 h. A condition effect was found for IL-10 and IL-6/IL-10 with a lower IL-10 and a greater IL-6/IL-10 for RR. A time effect demonstrated that IL-1β and IL-10 peaked at IP. IL-8 was increased from 5 min to 60 min and 24 h. IL-6/IL-10 was increased from PRE to 30 min, 60 min, and 24 h. These results suggested that rest period configuration- specific differences exist for the inflammatory response in trained women during intramuscular homoeostatic disruption.