Predicting the photodynamics of cyclobutanone triggered by a laser pulse at 200 nm and its MeV-UED signals-A trajectory surface hopping and XMS-CASPT2 perspective.

This work is part of a prediction challenge that invited theoretical/computational chemists to predict the photochemistry of cyclobutanone in the gas phase, excited at 200 nm by a laser pulse, and the expected signal that will be recorded during a time-resolved megaelectronvolt ultrafast electron diffraction (MeV-UED). We present here our theoretical predictions based on a combination of trajectory surface hopping with XMS-CASPT2 (for the nonadiabatic molecular dynamics) and Born-Oppenheimer molecular dynamics with MP2 (for the athermal ground-state dynamics following internal conversion), coined (NA+BO)MD. The initial conditions were sampled from Born-Oppenheimer molecular dynamics coupled to a quantum thermostat. Our simulations indicate that the main photoproducts after 2 ps of dynamics are CO + cyclopropane (50%), CO + propene (10%), and ethene and ketene (34%). The photoexcited cyclobutanone in its second excited electronic state S2 can follow two pathways for its nonradiative decay: (i) a ring-opening in S2 and a subsequent rapid decay to the ground electronic state, where the photoproducts are formed, or (ii) a transfer through a closed-ring conical intersection to S1, where cyclobutanone ring opens and then funnels to the ground state. Lifetimes for the photoproduct and electronic populations were determined. We calculated a stationary MeV-UED signal [difference pair distribution function-ΔPDF(r)] for each (interpolated) pathway as well as a time-resolved signal [ΔPDF(r,t) and ΔI/I(s,t)] for the full swarm of (NA+BO)MD trajectories. Furthermore, our analysis provides time-independent basis functions that can be used to fit the time-dependent experimental UED signals [both ΔPDF(r,t) and ΔI/I(s,t)] and potentially recover the population of photoproducts. We also offer a detailed analysis of the limitations of our model and their potential impact on the predicted experimental signals.

Determining Changes in Muscle Size and Architecture After Exercise Training: One Site Does Not Fit all.

ABSTRACT: Nunes, JP, Blazevich, AJ, Schoenfeld, BJ, Kassiano, W, Costa, BDV, Ribeiro, AS, Nakamura, M, Nosaka, K, and Cyrino, ES. Determining changes in muscle size and architecture after exercise training: One site does not fit all. J Strength Cond Res 38(4): 787-790, 2024-Different methods can be used to assess muscle hypertrophy, but the effects of training on regional changes in muscle size can be detected only using direct muscle measurements such as muscle thickness, cross-sectional area, or volume. Importantly, muscle size increases vary across regions within and between muscles after resistance training programs (i.e., heterogeneous, or nonuniform, muscle hypertrophy). Muscle architectural changes, including fascicle length and pennation angle, after resistance and stretch training programs are also region-specific. In this paper, we show that the literature indicates that a single-site measure of muscle shape does not properly capture the effects achieved after exercise training interventions and that conclusions concerning the magnitude of muscle adaptations can vary substantially depending on the muscle site to be examined. Thus, we propose that measurements of muscle size and architecture should be completed at multiple sites across regions between the agonist muscles within a muscle group and along the length of the muscles to provide an adequate picture of training effects.

Ultrafast electronic relaxation pathways of the molecular photoswitch quadricyclane.

The light-induced ultrafast switching between molecular isomers norbornadiene and quadricyclane can reversibly store and release a substantial amount of chemical energy. Prior work observed signatures of ultrafast molecular dynamics in both isomers upon ultraviolet excitation but could not follow the electronic relaxation all the way back to the ground state experimentally. Here we study the electronic relaxation of quadricyclane after exciting in the ultraviolet (201 nanometres) using time-resolved gas-phase extreme ultraviolet photoelectron spectroscopy combined with non-adiabatic molecular dynamics simulations. We identify two competing pathways by which electronically excited quadricyclane molecules relax to the electronic ground state. The fast pathway (<100 femtoseconds) is distinguished by effective coupling to valence electronic states, while the slow pathway involves initial motions across Rydberg states and takes several hundred femtoseconds. Both pathways facilitate interconversion between the two isomers, albeit on different timescales, and we predict that the branching ratio of norbornadiene/quadricyclane products immediately after returning to the electronic ground state is approximately 3:2.

Monitoring the Evolution of Relative Product Populations at Early Times during a Photochemical Reaction.

Identifying multiple rival reaction products and transient species formed during ultrafast photochemical reactions and determining their time-evolving relative populations are key steps toward understanding and predicting photochemical outcomes. Yet, most contemporary ultrafast studies struggle with clearly identifying and quantifying competing molecular structures/species among the emerging reaction products. Here, we show that mega-electronvolt ultrafast electron diffraction in combination with ab initio molecular dynamics calculations offer a powerful route to determining time-resolved populations of the various isomeric products formed after UV (266 nm) excitation of the five-membered heterocyclic molecule 2(5H)-thiophenone. This strategy provides experimental validation of the predicted high (∼50%) yield of an episulfide isomer containing a strained three-membered ring within ∼1 ps of photoexcitation and highlights the rapidity of interconversion between the rival highly vibrationally excited photoproducts in their ground electronic state.

Assessing post-fire water quality changes in reservoirs: Insights from a large dataset in Portugal.

Wildfires in the Mediterranean basin, especially in Portugal, have increased in extent and frequency over the last few years. One of the impacts of wildfires on humans and ecosystems is on the water quality of surface waters. Ashes and increased erosion rates might, for example, change oxygen levels and elevate the influx of sediments, nutrients, or other water quality-related components like metals and polycyclic aromatic hydrocarbons (PAHs), possibly affecting water supply. In this study, time series of eight water quality parameters: biological- and chemical oxygen demand (BOD and COD), electrical conductivity (EC), total phosphorous (TP), nitrate (NO3-), total suspended sediments (TSS), dissolved oxygen (DO), and pH, were assessed via changepoint analysis to identify events of post-fire water contamination in over 60 Portuguese reservoirs. Further, possible fire, watershed, reservoir, and climate-related drivers were linked with the occurrence of these contamination events through logistic regression using generalized additive models. All measured parameters exhibited post-fire changes, with some being more frequently affected than others. The concentrations of TP, NO3-, and TSS showed a noticeable increase following 9.6 %, 12.6 %, and 13.6 % of all wildfires, respectively. Most changes fell into the unusually large fire seasons of 2003-2005 and 2017. The most significant impacts could be seen in southern reservoirs after the fire seasons of 2003-2005. The burned area ratio of the watershed was identified as the main driver of post-fire water contamination, while reservoir and climate-related characteristics like water levels also played a significant role in some parameters. Increased levels of suspended sediments were identified as a potential threat to water supply, especially when large wildfires coincide with drought-induced low reservoir water levels. The identification of post-fire water contamination events and their drivers from large datasets can inform water managers about potential threats to water supply.

Hidden risk of terrestrial food chain contamination from organochlorine insecticides in a vegetable cultivation area of Northwest Bangladesh.

Organochlorine insecticide (OCI) exposures in terrestrial food chains from historical or current applications were studied in a vegetable production area in northwest Bangladesh. A total of 57 subsoil, 57 topsoil, and 57 vegetable samples, as well as 30 cow's milk samples, were collected from 57 farms. Multiple OCI residues were detected using GC-MS/MS with modified QuEChERS in 20 % of subsoils, 21 % of topsoils, 23 % of vegetables, and 7 % of cow's milk samples. Diversified OCI residues were detected in subsoils (17 residues with a concentration of 179.15 ± 148.61 µg kg-1) rather than in topsoils (3 DDT residues with a concentration of 25.76 ± 20.19 µg kg-1). Isomeric ratios indicate intensive historical applications of OCIs. According to Dutch and Chinese standards, the lower concentrations of individual OCI residues in the soil indicate negligible to slight soil pollution, assuming local farmers follow local pesticide use regulations. However, a maximum of 78.24 µg kg-1 ΣAldrines and 35.57 µg kg-1 ΣHCHs were detected (1-4 residues) in 60 % of brinjal, 28 % of cucumber, 29 % of sponge gourd, and 20 % of lady's finger samples, which could be a result of either historical or current OCI applications, or both. A strong positive correlation between aldrines in subsoils and cucurbit vegetables indicates greater bioaccumulation. Cow milk samples contained up to 6.96 µg kg-1 ΣDDTs, which resulted either from rationing contaminated vegetables or grazing on contaminated land. Individual OCI in both vegetables and cow's milk was below the respective maximum residue limits of US and FAO/WHO CODEX and poses little or no risk to human health. However, combined exposure to multiple pesticides could increase human health risks. A cumulative health risk assessment of multiple pesticide residues is suggested to assess the suitability of those soils for cultivation and grazing, as well as the safety of vegetables and cow's milk for human consumption.

EUSEDcollab: a network of data from European catchments to monitor net soil erosion by water.

As a network of researchers we release an open-access database (EUSEDcollab) of water discharge and suspended sediment yield time series records collected in small to medium sized catchments in Europe. EUSEDcollab is compiled to overcome the scarcity of open-access data at relevant spatial scales for studies on runoff, soil loss by water erosion and sediment delivery. Multi-source measurement data from numerous researchers and institutions were harmonised into a common time series and metadata structure. Data reuse is facilitated through accompanying metadata descriptors providing background technical information for each monitoring station setup. Across ten European countries, EUSEDcollab covers over 1600 catchment years of data from 245 catchments at event (11 catchments), daily (22 catchments) and monthly (212 catchments) temporal resolution, and is unique in its focus on small to medium catchment drainage areas (median = 43 km2, min = 0.04 km2, max = 817 km2) with applicability for soil erosion research. We release this database with the aim of uniting people, knowledge and data through the European Union Soil Observatory (EUSO).

Assessing the climate change adaptability of sustainable land management practices regarding water availability and quality: A case study in the Sorraia catchment, Portugal.

In Mediterranean catchments, such as the Sorraia catchment in Portugal, it is expected that climate change will increase drought stress and the deterioration of water quality in reservoirs. Sustainable land management (SLM) practices are seen as an adaption measure for those problems, but the effectiveness on improving climate change impacted water availability and quality on catchment scale is still poorly understood. Therefore, this study aims to evaluate the effectiveness of SLM practices in adapting the impacts of climate change on water availability and quality of the Montargil and Maranhão reservoirs in the Sorraia catchment. A well-calibrated Soil Water Assessment Tool model is used to simulate four scenarios (2041-2071 and 2071-2100; representative climate pathways 4.5 and 8.5), to investigate the effects of climate change on total phosphorus load (TP) in streams, reservoir volume, irrigation use and water exploitation index (WEI). Results showed that WEI will not exceed any water stress level while reservoir water quality will worsen. In particular since the TP load in streams flowing into the reservoirs increases and the volume decreases, it is likely that the existing P limitation for eutrophication will be counteracted. Nevertheless, tested SLM practices were able to decrease the TP load in those streams and increase the reservoir volume under future climates. Overall, this study shows that the SLM practices are effective in adapting to the climate change effects regarding reservoir water quality, without worsening the water availability; thus, it is a promising tool that should be investigated further for application by e.g. local land-users and decision makers.

The Effects of Carbohydrate Intake on Body Composition and Muscular Strength in Trained Men Undergoing a Progressive Resistance Training.

This study's purpose was to compare the effects of different carbohydrate (CHO) intakes on body composition and muscular strength following eight weeks of resistance training (RT) in pre-conditioned men. In addition, we explored the individual responses to different CHO intakes. Twenty-nine young men volunteered to participate in this study. The participants were divided into two groups according to their relative CHO intake: lower (L-CHO; n = 14) and higher (H-CHO; n = 15). Participants performed a RT program four days a week for eight weeks. The lean soft tissue (LST) and fat mass were determined by dual-energy X-ray absorptiometry. Muscular strength was determined by a one-repetition maximum (1RM) test in the bench press, squat, and arm curl exercises. Both groups increased LST (P < 0.05) with no statistical differences between conditions (L-CHO = +0.8% vs. H-CHO = +3.5%). Neither group demonstrated changes in fat mass. Both groups increased 1RM (P < 0.05) in the bench press (L-CHO = +3.6% vs. H-CHO = +5.8%) and squat (L-CHO = +7.5% vs. H-CHO = +9.4%); however, only H-CHO significantly increased arm curl 1RM (P < 0.05) at post-training (L-CHO = +3.0% vs. H-CHO = +6.6%). Responsiveness was greater in H-CHO vs. L-CHO for LST and arm curl 1RM. In conclusion, lower and higher CHO intakes promote similar increase in LST and muscular strength; however, a greater intake may improve the responsiveness to gains in lean mass and arm curl strength in pre-conditioned men.

Muscle Swelling of the Triceps Surae in Response to Straight-Leg and Bent-Leg Calf Raise Exercises in Young Women.

ABSTRACT: Kassiano, W, Costa, B, Kunevaliki, G, Soares, D, Stavinski, N, Francsuel, J, Carneiro, MAS, Tricoli, I, Nunes, JP, Ribeiro, AS, and Cyrino, ES. Muscle swelling of the triceps surae in response to straight-leg and bent-leg calf raise exercises in young women. J Strength Cond Res 37(7): e438-e443, 2023-Triceps surae muscle swelling in response to different resistance exercises remains to be determined. This study compared the effects of straight-leg (STRA-leg) calf raise vs. bent-leg (BENT-leg) calf raise exercises on triceps surae muscle swelling. Seventeen young women (23.7 ± 4.0 years; 67.4 ± 16.0 kg; and 163.5 ± 7.2 cm) performed 2 resistance training sessions; in one, they performed the STRA-leg calf raise, and in another, they performed the BENT-leg calf raise. A randomized, cross-over, and counterbalanced design was adopted for this investigation. The subjects performed 4 sets of 20 repetitions maximum until concentric muscular failure. The muscle thickness of the gastrocnemius medial (GM), gastrocnemius lateral (GL), and soleus (SOL) was taken through B-mode ultrasound before and immediately after the calf raise exercises. STRA-leg calf raise elicited greater increases in muscle thickness of GM (+8.8% vs. -0.9%, p < 0.001) and GL (+14.5% vs. +7.0%, p < 0.001) than BENT-leg calf raise. Conversely, BENT-leg calf raise elicited greater increases in SOL muscle thickness than STRA-leg calf raise (+15.4% vs. +7.7%, p < 0.001). From a practical perspective, the STRA-leg calf raise should be preferred if the aim is stimulating the 3 muscles that comprise the triceps surae, whereas the BENT-leg calf raise should be prioritized if the target muscle is the SOL.

Which ROMs Lead to Rome? A Systematic Review of the Effects of Range of Motion on Muscle Hypertrophy.

ABSTRACT: Kassiano, W, Costa, B, Nunes, JP, Ribeiro, AS, Schoenfeld, BJ, and Cyrino, ES. Which ROMs lead to Rome? a systematic review of the effects of range of motion on muscle hypertrophy. J Strength Cond Res 37(5): 1135-1144, 2022-Resistance exercise range of motion (ROM) influences muscular adaptations. However, there are no consistent practical guidelines about the optimal ROM for maximizing muscle hypertrophy. The objective of this article was to systematically review the literature for studies that compared the effects of full ROM (fROM) and partial ROM (pROM) on muscle hypertrophy. PubMed/MEDLINE, Scopus, and Web of Science databases were searched to identify articles from the earliest record up to and including April 2022. We calculated the effect size (ES) scores of the variables of interest. Eleven studies were included in the review. Full ROM and pROM performed in the initial part of the ROM elicited greater muscle hypertrophy of the rectus femoris, vastus lateralis, biceps brachii, and brachialis distal sites (between-groups ES: 0.20-0.90) than pROM performed in the final part of the ROM. fROM elicited greater muscle growth on the gluteus maximus and adductors than pROM in the final part of the ROM (between-groups ES: 0.24-0.25). Initial pROM produced more favorable proximal rectus femoris hypertrophy than fROM (between-groups ES: 0.35-0.38). pROM in the middle part of the ROM elicited greater triceps brachii hypertrophy than fROM (between-group ES: 1.21). In conclusion, evidence suggests that when training at a longer muscle length-through either pROM or fROM-some muscles, such as quadriceps femoris, biceps brachii, and triceps brachii, tend to experience optimal growth. Thus, the use pROM in the initial part of the excursion in combination with fROM training should be considered when prescribing hypertrophy-oriented resistance training programs.

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.

Does Stretching Training Influence Muscular Strength? A Systematic Review With Meta-Analysis and Meta-Regression.

ABSTRACT: Thomas, E, Ficarra, S, Nunes, JP, Paoli, A, Bellafiore, M, Palma, A, and Bianco, A. Does stretching training influence muscular strength? A systematic review with meta-analysis and meta-regression. J Strength Cond Res 37(5): 1145-1156, 2023-The aim of this study was to review articles that performed stretching training and evaluated the effects on muscular strength. Literature search was performed using 3 databases. Studies were included if they compared the effects on strength following stretching training vs. a nontraining control group or stretching training combined with resistance training (RT) vs. an RT-only group, after at least 4 weeks of intervention. The meta-analyses were performed using a random-effect model with Hedges' g effect size (ES). A total of 35 studies ( n = 1,179 subjects) were included in this review. The interventions lasted for a mean period of 8 weeks (range, 4-24 weeks), 3-4 days per week, applying approximately 4 sets of stretching of approximately 1-minute duration. The meta-analysis for the stretching vs. nontraining control group showed a significant small effect on improving dynamic (k = 14; ES = 0.33; p = 0.007) but not isometric strength (k = 8; ES = 0.10; p = 0.377), following static stretching programs (k = 17; ES = 0.28; p = 0.006). When stretching was added to RT interventions, the main analysis indicated no significant effect (k = 17; ES = -0.15; p = 0.136); however, moderator analysis indicated that performing stretching before RT sessions has a small but negative effect (k = 7; ES = -0.43; p = 0.014); the meta-regression revealed a significant negative association with study length (ß = -0.100; p = 0.004). Chronic static stretching programs increase dynamic muscular strength to a small magnitude. Performing stretching before RT and for a prolonged time (>8 weeks) can blunt the strength gains to a small-to-moderate magnitude. Performing stretching in sessions distant from RT sessions might be a strategy to not hinder strength development.

Estimating impact likelihoods from probabilistic projections of climate and socio-economic change using impact response surfaces.

Estimates of future climate change impacts using numerical impact models are commonly based on a limited selection of projections of climate and other key drivers. However, the availability of large ensembles of such projections offers an opportunity to estimate impact responses probabilistically. This study demonstrates an approach that combines model-based impact response surfaces (IRSs) with probabilistic projections of climate change and population to estimate the likelihood of exceeding pre-specified thresholds of impact. The changing likelihood of exceeding impact thresholds during the 21st century was estimated for selected indicators in three European case study regions (Iberian Peninsula, Scotland and Hungary), comparing simulations that incorporate adaptation to those without adaptation. The results showed high likelihoods of increases in heat-related human mortality and of yield decreases for some crops, whereas a decrease of NPP was estimated to be exceptionally unlikely. For a water reservoir in a Portuguese catchment, increased likelihoods of severe water scarce conditions were estimated for the current rice cultivation. Switching from rice to other crops with lower irrigation demand changes production risks, allowing for expansion of the irrigated areas but introducing a stronger sensitivity to changes in rainfall. The IRS-based risk assessment shown in this paper is of relevance for policy making by addressing the relative sensitivity of impacts to key climate and socio-economic drivers, and the urgency for action expressed as a time series of the likelihood of crossing critical impact thresholds. It also examines options to respond by incorporating alternative adaptation actions in the analysis framework, which may be useful for exploring the types, choice and timing of adaptation responses.

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.

Comparison between concentric-only, eccentric-only, and concentric-eccentric resistance training of the elbow flexors for their effects on muscle strength and hypertrophy.

PURPOSE: This study compared concentric-eccentric coupled (CON-ECC), concentric-only (CON), and eccentric-only (ECC) resistance training of the elbow flexors for their effects on muscle strength and hypertrophy. METHODS: Non-resistance-trained young adults were assigned to one of the four groups: CON-ECC (n = 14), CON (n = 14) and ECC (n = 14) training groups, and a control group (n = 11) that had measurements only. The training group participants performed dominant arm elbow flexor resistance training in extended elbow joint angles (0°-50°) twice a week for 5 weeks. The total training volume (dumbbell weight × number of contractions) in CON-ECC (5745 ± 1020 kg) was double of that in CON (2930 ± 859 kg) and ECC (3035 ± 844 kg), because 3 sets of 10 contractions were performed for both directions in CON-ECC. Maximum voluntary isometric (MVC-ISO), concentric (MVC-CON), and eccentric contraction (MVC-ECC) torque of the elbow flexors and biceps brachii and brachialis muscle thickness (MT) were measured at baseline, and 3-9 days post-last training session. RESULTS: No significant changes in any measures were evident for the control group. The CON-ECC and ECC groups showed increases (P < 0.05) in MVC-ISO (12.0 ± 15.7% and 11.3 ± 10.8%, respectively) and MVC-ECC torque (12.5 ± 18.3%, 16.2 ± 11.0%) similarly. Increases in MVC-CON torque (P < 0.05) were evident for the CON-ECC (17.5 ± 13.5%), CON (10.5 ± 12.8%), and ECC (14.2 ± 10.4%) groups without a significant difference among groups. MT increased (P < 0.01) after CON-ECC (10.6 ± 5.4%) and ECC (9.7 ± 7.2%) similarly, but not significantly after CON (2.5 ± 4.8%). CONCLUSIONS: ECC training increased muscle strength and thickness similarly to CON-ECC training, despite the half training volume, suggesting that concentric contractions contributed little to the training effects.

Muscular strength and skeletal muscle mass in 511 physically independent older women aged 60-88 years.

Although one-repetition maximum (1RM) and lean soft tissue (LST) are the most common measures to assess muscular strength and skeletal muscle mass in older adults, reference data is still missing. Therefore, the present study aimed to produce reference values for the 1RM tests and LST in physically independent older women. Furthermore, the effect of age and body segment on these outcomes was examined. Five hundred and eleven older women aged 60-88 years participated in the present study. The 1RM tests were performed on chest press, leg extension, and preacher curl exercises. Dual-energy X-ray absorptiometry exams were used to determine total and segmental LST. The 1RM and LST average values: chest press = 44.0 ± 11.1 kg, leg extension = 48.8 ± 11.8 kg, preacher curl = 21.6 ± 5.4 kg; trunk LST = 19.0 ± 2.7 kg, lower-limbs LST = 12.5 ± 1.9 kg, upper-limbs LST = 4.0 ± 0.7 kg, appendicular LST = 16.6 ± 2.6, total LST = 38.5 ± 5.2 kg. The age-related declines in 1RM chest press and leg extension were higher than in preacher curl. The present study provides reference values for 1RM of different body segments and total and segmental LST in older women. In addition, our results revealed a reduction of muscular strength and LST with increasing age, and the magnitude of the age-related strength reduction depends on the body segment analyzed.

Does Varying Resistance Exercises Promote Superior Muscle Hypertrophy and Strength Gains? A Systematic Review.

ABSTRACT: Kassiano, W, Nunes, JP, Costa, B, Ribeiro, AS, Schoenfeld, BJ, and Cyrino, ES. Does varying resistance exercises promote superior muscle hypertrophy and strength gains? A systematic review. J Strength Cond Res 36(6): 1753-1762, 2022-Fitness professionals routinely employ a variety of resistance training exercises in program design as a strategy to enhance muscular adaptations. However, it remains uncertain whether such an approach offers advantages over a fixed-exercise selection. The objective of this review was to review the effects of exercise variation on muscle hypertrophy and strength. A search of the literature was conducted using PubMed/MEDLINE, Scopus, and Web of Science databases. Eight studies were identified as meeting inclusion criteria. The combined total sample of the studies was N = 241, comprising all young men. The methodological quality of included studies was considered "good" and "excellent" based on the Physiotherapy Evidence Database Scale. The available studies indicate that varying exercise selection can influence muscle hypertrophy and strength gains. Some degree of systematic variation seems to enhance regional hypertrophic adaptations and maximize dynamic strength, whereas excessive, random variation may compromise muscular gains. We conclude that exercise variation should be approached systematically with a focus on applied anatomical and biomechanical constructs; on the contrary, employing different exercises that provide a redundant stimulus, as well as excessive rotation of different exercises (i.e., high frequency of change), may actually hinder muscular adaptations.