Lower-body Performance Research Articles

Similar adaptive responses in the upper body physical performance of table tennis players following the traditional and cluster set resistance and plyometric training

Numerous studies have investigated the impact of resistance training (RT) and plyometric training (PT) set configurations (cluster sets [CS] and traditional sets [TS]) on lower body performance adaptations. However, the effects of these training modalities on upper body physical performance, particularly among Table Tennis (TT) players, remain unclear. Therefore, this study aimed to examine the effects of an 8-week RT and PT using CS and TS configurations on the physical performance attributes of male TT players. Forty young male players were recruited from a local academy and after determining their dominant hand, divided into CS-PT, TS-PT, CS-RT, TS-RT, and active control (CON) groups, each of eight. Pre- and post-interventions, the upper body muscular power (medicine ball throw), maximal strength (bench press), reaction time, and arm crank anaerobic power test were measured. Following the intervention, the CON group exhibited no changes; however, the CS-PT, TS-PT, CS-RT, and TS-RT groups displayed significant (p = 0.001) improvements in muscular power (effect size [ES] = 1.21 [large], 1.02 [medium], 0.81 [medium], 0.64 [medium]), strength (ES = 0.40 [small], 0.43 [small], 0.62 [medium], 0.63 [medium]), reaction time (ES = − 0.71 [medium], − 0.68 [medium], − 0.83 [medium], − 0.61 [medium]), peak power (ES = 1.83 [large], 1.66 [large], 0.90 [medium], 0.67 [medium]), and mean power (ES = 0.89 [medium], 0.89 [medium], 0.57 [small], 0.59 [small]), respectively. The PT groups indicated significantly greater changes than the RT groups in both muscular (CS, p = 0.021; TS, p = 0.018) and anaerobic power (peak power: CS, p = 0.017; TS, p = 0.011; mean power: CS, p = 0.024; TS, p = 0.042) performance, while the RT groups showed greater adaptive responses than the PT groups in maximal strength (CS, p = 0.033; TS, p = 0.048). In conclusion, PT is recommended for enhancing power performance, while RT is preferred for increasing strength. When various set configurations were incorporated, no further effects were noted.

Effects of different strength and velocity training programs on physical performance in youth futsal players

Futsal is a high intensity team sport with intermittent actions of short duration, so it is necessary to include different training strategies to improve explosive actions. There is a gap in the scientific literature regarding training programs that improve the performance of young futsal players. The aim of this study was to determine the effects of different strength and velocity training programs on lower body physical performance in youth futsal players. Forty-two youth futsal players were divided into control group (CG, n = 14) and a strength intervention group (SG, n = 14), which included a weekly session for 8 weeks of eccentric strength training, plyometrics and core strengthening, and a velocity intervention group (VG, n = 14), which included a weekly session during 8 weeks of training with linear speed exercises and with change of direction, accelerations with resistance bands and core strengthening. SG significantly improved horizontal jump (HJ) (p:0.02), V-CUT (p:0.91) and change of direction deficit (CODD) (p:0.01). VG showed significant improvements in HJ (p:0.01), in 25 m sprint (p:0.01), in total repeated sprint ability time (p:0.01), in V-CUT (p:0.01) and in CODD (p:0.01). SG showed significant intergroup differences (p:0.01) in COD variables with respect to CG and VG. In conclusion, SG and VG showed significant improvements in lower body performance variables in youth futsal players. In addition, the SG has substantial changes in COD compared to the other two groups, so it has a greater effect.

Inclusion of a connected adaptive resistance exercise machine in a 6-week training regimen with collegiate basketball players

In this study, we aimed to determine the effects of incorporating connected adaptive resistance exercise (CARE) into a training regimen with collegiate basketball players on lower body performance metrics. Thirty-two male participants (aged 18-26) with collegiate basketball experience trained thrice weekly for 6 weeks with a periodized training program that included CARE and were randomized 1:1 and blinded to an intervention group (n = 16; where the CARE used accentuated eccentric loading (AEL)) or an active control group (n = 16; where the CARE did not use accentuated eccentric loading (ACTL)). Standard anthropomorphic measures along with one repetition maximum (1-RM) back squat, vertical jump height, and peak power were assessed prior to and following completion of the training regimen. Both groups demonstrated significant increases in 1-RM back squat, jump height, and peak power (both p < .001). However, AEL yielded significantly greater improvements compared to ACTL across these measures (p <.001, g = 0.91; p <.001, g = 0.89; p <.001, g = 0.92, respectively). The findings of the present study demonstrate that the inclusion of CARE may be a superior strategy for improving performance variables of lower-body strength, peak power and jump height for male collegiate basketball players.

Risk and Protective Factors for Frailty in Pre-Frail and Frail Older Adults.

This study aims to evaluate the differences in body composition, physical function, and physical activity between pre-frail/frail older adults and to detect risk and protective factors against frailty and physical frailty. Fried's criteria for frailty and physical frailty using the short-performance physical battery (SPPB) were measured in 179 older participants (75.3 ± 6.4 years old). Body weight, height, and waist, arm, and leg circumferences were obtained as body composition variables. Daily accelerometer outcomes (physical activity and inactivity) were obtained. Pre-frail participants showed overall better physical function and spent more time in physical activity and less time in long inactivity periods than frail participants (p < 0.05). Risk frailty factors were higher waist perimeter (Odds Ratio [OR]: 1.032, 95%CI: 1.003-1.062), low leg performance (OR: 1.025, 95%CI: 1.008-1.043), and inactivity periods longer than 30 min (OR:1.002, 95%CI: 1.000-1.005). Protective factors were standing balance (OR:0.908, 95%CI: 0.831-0.992) and SPPB score (OR: 0.908, 95%CI: 0.831-0.992) for frailty, handgrip strength (OR: 0.902, 95%CI: 0.844-0.964) for physical frailty, and light (OR: 0.986, 95%CI: 0.976-0.996) and moderate-to-vigorous (OR: 0.983, 95%CI: 0.972-0.996) physical activity for both. Our findings suggest that handgrip strength, balance, and physical activity are protective frailty factors and can be monitored in pre-frail older adults. Moreover, poor lower body performance and long inactivity periods are frailty risk factors, which highlights their importance in frailty assessment.

Does Dominant Somatotype Differentiate Performance of Jumping and Sprinting Variables in Young Healthy Adults?

The relationship between an athlete’s somatotype three-numeral rating and his or her athletic performance is well known. However, a direct effect of the different dominant somatotype on jumping and sprinting variables has not yet been reported. The aim of this study was to investigate the effects of dominant somatotype on sport-specific explosive variables. One hundred and twelve physically active young adults (mean ± standard deviation age: 21.82 ± 3.18 years) were somatotype-rated using the Heath–Carter method. Participants were classified as balanced ectomorph, balanced mesomorph, central, mesomorph-endomorph, and mesomorphic ectomorph. Vertical jump and linear sprint tests were performed to measure peak lower body performance and sprint variables (time, speed, and momentum), respectively. The analysis revealed that balanced mesomorph had significantly higher vertical jump (effect size (ES) = 1.10, p = 0.005) and power to body mass (ES = 1.04, p = 0.023) than mesomorph-endomorph. In addition, balanced mesomorph showed significantly superior performance in 30-m sprint time and velocity than central and mesomorph-endomorph (ES range = 0.93–1, p < 0.05). Finally, balanced ectomorph (ES = 1.12, p = 0.009) and mesomorphic ectomorph (ES = 1.10, p = 0.017) were lower in sprint momentum compared to balanced mesomorphs. In conclusion, this study has shown the importance of the interaction between subtypes and athletic performance. The knowledge gained may be important in identifying those who tend to perform well in sports with explosive power and in prescribing training programs.

Training in virtual reality enables learning of a complex sports movement

Despite the increased use in sports, it is still unclear to what extent VR training tools can be applied for motor learning of complex movements. Previous VR studies primarily relate to realize performances rather than learning motor skills. Therefore, the current study compared VR with video training realizing the acquisition of karate technique, the Soto Uke moving forward in Zenkutsu Dachi, without being accompanied by a trainer or partner. Further analyses showed whether a less lavished forearm compared to a whole-body visualization in VR is necessary to acquire movements’ basics sufficiently. Four groups were tested: 2 groups conducted VR training (VR-WB: whole-body visualization, and VR-FA having only visualized the forearms), the third group passed through a video-based learning method (VB), and the control group (C) had no intervention. In consultation with karate experts, a scoring system was developed to determine the movements’ quality divided, into upper- and lower body performance and the fist pose. The three-way ANOVA with repeated measurements, including the between-subject factor group [VR-WB, VR-FA, VB, C] and the within-subject factors time [pre, post, retention] and body regions [upper body, lower body, fist pose], shows that all groups improved significantly (except for C) with the similar course after four training sessions in all body regions. Accordingly, VR training seems to be as effective as video training, and the transfer from VR-adapted skills into the natural environment was equally sufficient, although presenting different body visualization types. Further suggestions are made related to the features of future VR training simulations.

Beta-alanine supplementation and anaerobic performance in highly trained judo athletes

Introduction. Previous studies have shown that several weeks of beta-alanine (BA) supplementation increases anaerobic work capacity and decreases muscular fatigue, but limited research was conducted on elite martial arts athletes. Therefore, the purpose of this study was to investigate the effect of chronic BA supplementation on high-intensity intermittent upper and lower-body performance in highly-trained judo athletes. Material and Methods: Sixteen elite judo athletes (21.8 ± 2.5 years old) were randomly assigned to receive either BA (4 g/d over the first 2 weeks and 6 g/d in the last 2 weeks) or placebo for 4 weeks. Before and after BA supplementation, the athletes completed two double 30-s upper and lower limb Wingate tests, separated by 3 min. Blood samples were collected for lactate and di-carbonate concentration at baseline and post-exercise. Results: BA supplementation improved Lower and Upper Limb Total Work (p &lt; 0.001) and Upper Limb Mean Power (p &lt; 0.001) during Wingate Test. However, there were no significant differences in Lower Limb Mean Power in the BA group and in any obtained results in the placebo group. Additionally, a significant increase in the postworkout lactate and di-carbonate concentration (p &lt; 0.001) was observed. Conclusions: Chronic supplementation of BA effectively enhances high-intensity intermittent upper and lower-body performance in highly-trained judo athletes.

Physical fitness and throwing speed in U13 versus U15 male handball players

BackgroundThe aim of this study was to analyze the shoulder functional profile (rotation range of motion [ROM] and strength), upper and lower body performance, and throwing speed of U13 versus U15 male handball players, and to establish the relationship between these measures of physical fitness and throwing speed.MethodsOne-hundred and nineteen young male handball players (under (U)-13 (U13) [n = 85]) and U15 [n = 34]) volunteered to participate in this study. The participating athletes had a mean background of sytematic handball training of 5.5 ± 2.8 years and they exercised on average 540 ± 10.1 min per week including sport-specific team handball training and strength and conditioning programs. Players were tested for passive shoulder range-of-motion (ROM) for both internal (IR) and external rotation (ER) and isometric strength (i.e., IR and ER) of the dominant/non-dominant shoulders, overhead medicine ball throw (OMB), hip isometric abductor (ABD) and adductor (ADD) strength, hip ROM, jumps (countermovement jump [CMJ] and triple leg-hop [3H] for distance), linear sprint test, modified 505 change-of-direction (COD) test and handball throwing speed (7 m [HT7] and 9 m [HT9]).ResultsU15 players outperformed U13 in upper (i.e., HT7 and HT9 speed, OMB, absolute IR and ER strength of the dominant and non-dominant sides; Cohen’s d: 0.76–2.13) and lower body (i.e., CMJ, 3H, 20-m sprint and COD, hip ABD and ADD; d: 0.70–2.33) performance measures. Regarding shoulder ROM outcomes, a lower IR ROM was found of the dominant side in the U15 group compared to the U13 and a higher ER ROM on both sides in U15 (d: 0.76–1.04). It seems that primarily anthropometric characteristics (i.e., body height, body mass) and upper body strength/power (OMB distance) are the most important factors that explain the throw speed variance in male handball players, particularly in U13.ConclusionsFindings from this study imply that regular performance monitoring is important for performance development and for minimizing injury risk of the shoulder in both age categories of young male handball players. Besides measures of physical fitness, anthropometric data should be recorded because handball throwing performance is related to these measures.

May a Nonlocalized Postactivation Performance Enhancement Exist Between the Upper and Lower Body in Trained Men?

Bartolomei, S, De Luca, R, and Marcora, SM. May a nonlocalized postactivation performance enhancement exist between the upper and lower body in trained men? J Strength Cond Res 37(1): 68-73, 2023-The aim of this study was to establish whether a resistance exercise for the upper body may generate a postactivation performance enhancement (PAPE) in the lower body. Thirteen resistance-trained men (age = 26.4 ± 3.3 years, body mass = 76.9 ± 6.3 kg, and height = 177.6 ± 5.2 cm) participated in the present investigation and were tested for upper-body and lower-body power (bench press throw and countermovement jump power [CMJP] tests). Subjects were also tested for maximum force and electromyographic (EMG) activation of quadriceps muscles while performing an isometric leg extension. All assessments were performed before and 8 minutes after a high-intensity (HI: 5 sets of 1 rep at 90% of 1 repetition maximum [1RM]) bench press protocol, a high-power protocol (POW: 5 sets of 1 rep at 30% of 1RM with maximum explosive intent), and a control trial (CON). Subjects performed all trials in a randomized order and on different days. A significant trial × time interaction was detected for CMJP ( p = 0.049). This parameter was significantly increased following the HI protocol only ( p = 0.024). A significant interaction was also noted for EMG with a significant improvement following the HI protocol ( p = 0.032) and a significant decrease following the POW protocol ( p = 0.020). No other significant effects were detected ( p > 0.05). The results of this investigation indicate that a HI bench press protocol may produce a PAPE in the lower-body power and increase the neuromuscular activation of leg extensor muscles. The POW bench press protocol did not show any positive effects on lower-body performance. Athletes and practitioners may take advantage from the inclusion of upper-body HI resistance exercises throughout complex resistance workouts to improve lower-body power output.

Impact of Low Volume Velocity-Controlled vs. Repetition to Failure Resistance Training Session on Measures of Explosive Performance in a Team of Adolescents Basketball Players.

This study examined the short-term effects (post 6 h and 24 h) of two equated (70% of 1 repetition maximum (1-RM)) low volume resistance exercise protocols: (i) velocity-controlled (VC) and (ii) repetition to failure (RTF) on upper and lower body performance in competitive adolescent male basketball players. Following a randomized, counterbalanced design, ten participants (age: 16 ± 0.5 years) completed either VC or RTF separated by 72 h. VC consisted of 4 sets of 5 explosive repetitions (≥90% of the maximum velocity). RTF involved 2 sets of 10-RM (with no velocity control). Measurements of 20-m sprint, countermovement jump (CMJ) and medicine ball toss (MBT) were collected before (baseline), post 6 h and 24 h after either VC or RTF. Increases of CMJ post 6 h (VC, +6.7%; RTF, +2.4%) and MBT post 24 h (VC, +4.6%; RTF, +4.2%) were observed after both VC and RTF. Only VC potentiated CMJ after 24 h (+2.0 ± 2.3%). No other changes or differences between protocols were observed. Performing a low volume exercise protocol, either VC or RTF, induced similar potentiation effects on the vertical jump (post 6 h) and medicine ball toss (post 24 h) in adolescent basketball players. Only the VC protocol was still effective to potentiate CMJ performance after 24 h.

United States Special Operations Command South Training Program’s Effectiveness: A Case Study

United States Special Operations Command South (SOCSOUTH) plans and coordinates Special Operations to find and fix threats and enable the Interagency, Intelligence Community, and Partner Nations to counter threats to US interests, maintain regional stability and compete in a complex environment. Physical readiness, performance optimization, and injury prevention are critical to the individual operator. SOCSOUTH has allocated significant financial resources associated with operational training and human performance programs in order to improve and maintain operators’ tactical and physical readiness. Whether these efforts are pointed to the right direction are under evaluation. PURPOSE: To evaluate the effectiveness of a 3 months’ customized training program on SOCSOUTH operators. METHODS: Retrospective data of ten operators (Age 41.1 ± 6.6) who participated in a customized training program for 3 months were analyzed to evaluate program’s effectiveness. Program was designed to improve operational training and human performance, while reducing the risk of musculoskeletal injuries based on microcycle periodization. Pre/Post testing was performed on selected tests, reflective of important mission qualities, to assess upper body muscular endurance (# chin-ups), lower body muscular endurance (150-yard shuttle test), and agility (30-yard sprint). A repeated-measures design for pre/post examined variables performed using SPSS©. RESULTS: There was a significant effect of post-training compared to pre-training on operators’ number of chin-ups performed (F1,9 = 10.42, p = .01, η2 = .54), 150-yard shuttle time (F1,9 = 38.29, p < .001, η2 = .81), and 30-yard time (F1,9 = 16.29, p = .003, η2 = .64) respectively. CONCLUSIONS: The current SOCSOUTH’s efforts on improving operational performance by applying a customized training program was successful. Operators’ selected mission quality capacities for upper- and lower-body performance and agility were improved. SOCSOUTH needs to continue supporting operators’ training based on these data analytics.

Effects of an Amylopectin-Chromium Complex Plus Whey Protein on Strength and Power After Eight Weeks of Resistance Training

Background: Previously we reported that acute supplementation with an amylopectin- chromium complex combined with a six-gram dose of whey protein increased rates of muscle protein synthesis. The purpose of this study was to examine if chronic supplementation with the same amylopectin-chromium complex plus a higher dose of protein could impact resistance training adaptations, recovery, and biomarkers of safety.Methods: Using a randomized, active-controlled, double-blind design, 35 recreationally active men (mean ± age, height, weight: 40.9 ± 7.6 y, 180.2 ± 6.1 cm, 95.8 ± 14.5 kg) were matched according to HOMA-IR and resistance-training experience and then randomly allocated to one of three groups: an active group consisting of 2 g amylopectin-chromium complex + 15 g whey protein isolate (V15P), an equivalent dose of whey protein isolate (15 g of whey protein, 15P), or a 30 gram dose of whey protein isolate (30P). Subjects consumed their respective supplement immediately following resistance exercise on days when training occurred and at the same time of day on non-training days. At 0, 4, and 8 weeks of training, body composition (4C via DXA, Bod Pod, Bioimpedance), whole-body protein balance (oral 15N-alanine), upper body and lower body performance (bench press, squat, jump power), and visual analog scale (VAS) scores for recovery, sleep quality, energy, willingness to train, and muscle soreness were assessed. Safety assessments included systemic hemodynamics, complete blood count, and comprehensive metabolic panels. Results: All groups gained strength, increased fat-free mass, and improved muscle size. Similarly, all groups increased squat repetitions to failure (RTF), with V15P experiencing a greater increase (+25.3 reps, p = 0.02) when compared to 15P (+12.0 reps) and 30P (+13.9 reps). After normalizing data to body mass, vertical jump power increased (p = 0.03) more for V15P (+2.1 Watts/kg) than either 15P (+0.4 Watts/kg) or 30P (+0.3 Watts/kg). Vertical jump height calculated from power output increased more in V15P (+8.7 cm, p = 0.04) than 15P (+1.6 cm) and 30P (+0.9 cm). Net protein balance was greater (p = 0.04) in V15P compared to 15W and 30W at four weeks (p &lt; 0.05), but this difference was not observed after eight weeks (p = 0.51). No changes in VAS were identified between groups. Diastolic blood pressure decreased in V15P (p = 0.002) compared to the other groups, and outside of an interaction for creatinine and aspartate aminotransferase (which still remained well within clinical limits), all blood- based markers of safety demonstrated no differences between groups.

The effect of custom-fitted compression garments worn overnight for recovery from judo training in elite athletes

ABSTRACT This study investigated the effects of custom-fitted compression garments (CG) worn during recovery over a multi-day training camp in elite judo players (judoka). A single blind, placebo-controlled study was carried out in 11 elite judoka, using a two-way crossover design. Two three-day training camps were completed in CG and placebo conditions in a random order. Changes in performance and physiological markers were compared between conditions. Judoka were assessed before training for (maximal) isometric knee extension and grip strength, countermovement jump performance and bench-press velocity, alongside soreness, limb circumferences, plasma creatine kinase activity (CK) and perceived bruising. Measurements were repeated after 12, 36 and 43 h of training, whereupon judoka rated the effectiveness of each intervention. Knee extension and bench-press performance demonstrated significant familiarization (p < 0.001), and were excluded from subsequent analysis. Jump performance was unaffected by training (p > 0.05). Grip strength declined throughout training (p < 0.001), with peak decrements of −9.7% indicating mild muscle damage. Increases in bruising, CK and soreness demonstrated highly variable, if significant (p < 0.001) responses. Although CG were perceived as significantly more effective than placebo for recovery (p = 0.046), no effects were observed for any other outcome (p > 0.05). Compression conferred no statistically significant impact upon recovery markers in elite judoka throughout training. Muscle damage responses were inconsistent in this population. Individual athletes would be advised to monitor habitually-used performance measures while using CG to ascertain whether perceptual benefits translate into enhanced recovery. Highlights Compression garments were perceived as more effective for recovery than placebo by elite judoka. However, no measures of performance or muscle damage were enhanced by CG. Randori was associated with inconsistent muscle damage responses in elite judoka, while lower-body performance was not impaired. Individual athletes would be advised to monitor habitually-used performance measures while using CG to ascertain whether perceptual benefits translate into enhanced recovery.

Hormonal, Psychological, And Muscle Damaging Effects Of An Acute Bout Of Farmers' Walk Resistance Exercise

The Farmers’ Walk (FW) exercise may help to enhance resistance training programs by incorporating movements which supplement functional tasks such as lifting and carrying weight over various distances. Minimal information exists concerning the intramuscular responses associated with FW performance, which may negatively promote perception and application of this exercise in prescribed protocols. PURPOSE: To investigate the hormonal, psychological, and muscle damaging effects of an acute bout of the Farmers’ Walk Carry (FWC) when compared to an individual’s unloaded walking pattern (NWC). METHODS: Fifteen participants (mean ± SEM; age: 21.6 ± 0.5 yrs; height: 172.5 ± 2.4 cm; weight: 81.8 ± 4.0 kg) completed a series of testing sessions. In the initial session, participant’s demographic information, anthropometrics, body composition, lower body power, and strength were measured. Subsequently, participants completed two counter-balanced conditions during which they performed 10 repetitions of a 20 m walk while either carrying 70% of their 1-repetition maximum deadlift or non-weighted walk. Participants were allowed a 30 s rest period after odd-numbered repetitions, and 2 min of rest after even-numbered repetitions. Participants provided self-reported evaluations of muscle soreness (VPMS), blood sampling for myoglobin (Mb) and creating kinase (CK-MB), and saliva samples for testosterone (T) which were collected prior to the exercise protocol, immediately after the exercise protocol, and 30- and 60-min after completion of the exercise. Post-exercise assessment consisted of blood sampling, saliva, countermovement jump (CMJ) height, and VPMS scores collected at 24 h, 48 h, and 72 h in both conditions. RESULTS: Increases were observed for overall (p<0.001) and upper body VPMS measurements (p<0.01) along with decreases in CK-MB (p=0.04) during the FWC. No significant differences were revealed for Mb, T, or CMJ height. CONCLUSIONS: The discrepancy found between upper- and lower-body muscle soreness (VPMS) during the FWC may be related to differences in primary muscle recruitment and their joint concentric, eccentric, and isometric muscle actions. These variances may have indirectly minimized post-exercise muscle damage, hormonal responses, and neuromuscular inhibitions of lower body performance.

Effects of Rest Position on Morphology of the Vastus Lateralis and Its Relationship with Lower-Body Strength and Power.

Ultrasonography of the lower body typically encompasses supine rest due to fluid shifts affecting tissue size and composition. However, vastus lateralis (VL) examination is completed in the lateral recumbent position, and this positional change may influence morphology and its ability to predict function. This study aimed to examine the effect of position on VL morphology and its relationship with lower-body performance. Cross-sectional area (CSA), muscle thickness (MT), pennation angle (PA), echo intensity (UnCorEI), subcutaneous adipose tissue thickness (SFT), and echo intensity corrected for SFT (CorEI) were assessed in 31 resistance-trained males (23.0 ± 2.1 yrs; 1.79 ± 0.08 m; 87.4 ± 11.7 kg) immediately after transitioning from standing to supine (IP), after 15 min of standing (ST), and after 15 min of rest in three recumbent positions: supine (SUP), dominant lateral recumbent (DLR), non-dominant lateral recumbent (NDLR). Participants also completed unilateral vertical jumps, isometric/isokinetic tests, and a one-repetition maximum leg press. CSA, MT, PA, and SFT were greater in ST compared to NDLR, DLR, and SUP (p < 0.05). CSA, UnCorEI, and CorEI were different between recumbent positions; however no differences were observed for MT, PA, and SFT. Different magnitudes of relationships were observed between muscle morphological characteristics measured after rest in different positions and performance variables. Muscle morphology in IP generally appears to be the best predictor of performance for most variables, although utilizing the NDLR and DLR positions may provide comparable results, whereas morphology measured in ST and SUP provide weaker relationships with physical performance. IP also requires less time and fewer requirements on the technician and subject, thus researchers should consider this positioning for VL examination.

Resistance Priming to Enhance Neuromuscular Performance in Sport: Evidence, Potential Mechanisms and Directions for Future Research.

Recent scientific evidence supports the use of a low-volume strength-power 'resistance priming' session prior to sporting competition in an effort to enhance neuromuscular performance. Though research evidence relating to this strategy is presently limited, it has been shown to be effective in improving various measures of neuromuscular performance within 48h. Post-activation potentiation strategies have previously been shown to enhance strength-power performance within 20min of completing maximal or near-maximal resistance exercise. Comparably, a delayed potentiation effect has been demonstrated following 'resistance priming' at various times between 1 and 48h in upper- and lower-body performance measures. This may have significant implications for a range of athletes when preparing for competition. Various exercise protocols have been shown to improve upper- and lower-body neuromuscular performance measures in this period. In particular, high-intensity resistance exercise through high loading (≥ 85% 1 repetition maximum) or ballistic exercise at lower loads appears to be an effective stimulus for this strategy. Although current research has identified the benefits of resistance priming to some physical qualities, many questions remain over the application of this type of session, as well as the effects that it may have on a range of specific sporting activities. The aims of this brief review are to assess the current literature examining the acute effects (1-48h) of resistance exercise on neuromuscular performance and discuss potential mechanisms of action as well as provide directions for future research.

Relative importance of four functional measures as predictors of 15-year mortality in the older Dutch population

BackgroundDecreased physical function is known to raise mortality risk. Little is known about how different physical function measures compare in predicting mortality risk in older men and women. The objective of this study was to compare four, objective and self-reported, physical function measures in predicting 15-year mortality risk in older men and women.MethodsData were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study in a population-based sample of the older Dutch population, sampled from municipal records. The 1995–96 cycle, including 727 men and 778 women aged 65–88 years, was considered as the baseline. Mortality was followed up through September 1, 2011. Physical function measures were: lower-body performance (chair stands test, walk test and tandem stand); handgrip strength (grip strength dynamometer); lung function (peak expiratory flow rate); functional limitations (self-report of difficulties in performing six activities of daily living). Cox proportional hazard models were used to determine the predictive value of each physical function measure for 15-year mortality risk, adjusted for demographic, lifestyle and health variables as potential confounders.Results1031 participants (68.5%) had died. After adjustments for confounders, in models assessing single functional measures, peak flow was the strongest predictor of all-cause mortality in men (HR 1.76, CI 1.38–2.26, CI) and lower-body performance in women (HR 1.97,CI 1.40–2.76, CI). In a model including all four functional measures only peak flow was statistically significant in predicting mortality in both genders (men HR 1.54,CI 1.18–2.01 and women HR 1.45,CI 1.08–1.94). In women, lower-body performance (HR 1.66, CI 1.15–2.41) followed by grip strength (HR 1.38, CI 1.02–1.89), and in men, functional limitations (HR 1.43, CI 1.14–1.8) were the other significant predictors of all-cause mortality.ConclusionBoth objective and self-reported measures of physical functioning predicted all-cause mortality in a representative sample of the older Dutch population to different extents in men and women. Peak flow contributed important unique predictive value for mortality in both men and women. In women, however, lower-body performance tests had better predictive ability. A second-best predictor in men was self-reported functional limitations. Peak flow, and possibly one of the other measures, may be used in clinical practice for assessment in the context of time constraints.

Threshold of Energy Deficit and Lower-Body Performance Declines in Military Personnel: A Meta-Regression.

Negative energy balance (EB) is common during military operations, diminishing body mass and physical performance. However, the magnitude of negative EB where performance would still be maintained is not well defined. Our objective was to explore relationships between EB and physical performance during military operations and define an acceptable negative EB threshold where performance may be maintained. A systematic search was performed for studies that measured EB and physical performance during military training. A total of 632 articles and technical reports were screened. Lower-body power and strength were the most common performance tests across investigations and were used as physical performance outcomes. Data were extracted from nine eligible studies containing 15 independent subgroups. Meta-regression assessed changes in performance in relation to study duration (days), average daily EB, and total EB (daily EB × duration). Changes in physical performance were not associated with average daily EB or training duration. Total EB was associated with changes in lower-body power (r2 = 0.764, P < 0.001) and strength (r2 = 0.836, P < 0.001) independently and combined (r2 = 0.454, P = 0.002). Predictive equations generated from the meta-regression indicated that, for a zero to small (2%) decline in performance, total EB should be limited to - 5686 to - 19,109kcal, for an entire operation, whereas total EB of - 39,243 to - 59,377kcal will result in moderate (7%) to large (10%) declines in performance. These data demonstrated that greater total negative EB is associated with declines in lower-body performance during military operations.

Tumor necrosis factor-alpha and soluble TNF-alpha receptor responses in young vs. middle-aged males following eccentric exercise

BackgroundTumor necrosis factor-alpha (TNF-α) has been shown to be implicated in both muscle regeneration and muscle wasting. However, it remains unclear whether TNF-α is responsible for the age-related losses in muscle size and function. Also, due to the high clearance rate of TNF-α from circulation, analyzing the circulating levels of soluble TNF-α receptors 1 and 2 (STNFR1 and STNFR2) may provide a better indication of inflammatory events. The aim of this study was to examine changes in circulating concentrations of TNF-α, STNFR1, and STNFR2 following acute eccentric exercise in young (YA) and middle-aged (MA) men. Methods and materialsNine YA (N=9, 21.8±2.2y, 179.5±4.9cm, 91.2±12.2kg, 21.8±4.3% body fat) and ten MA (N=10, 47.0±4.4y, 176.8±7.6cm; 96.0±21.5kg, 25.4±5.3% body fat) men completed an acute muscle damaging protocol (MDP). Blood samples were obtained at baseline (BL), immediately (IP), 30-minute (30P), 60-minute (60P), 120-minute (120P), 24-hour (24H), and 48-hour (48H) post-MDP. Lower body performance was assessed via isokinetic dynamometer at BL, IP, 120P, 24H, and 48H. ResultsYA displayed higher values of peak torque (p=0.023) and mean torque (p=0.036) at BL. No significant group differences were observed for markers of muscle damage or TNF-α. Plasma concentrations of TNF-α were unchanged following MDP. STNFR1 concentrations were significantly higher in the YA group compared to MA (p=0.036). Significant time effects were observed for STNFR1 (p<0.001) and STNFR2 (p=0.001). With both groups combined, serum STNFR1 was decreased at 30P (p=0.001), while STNFR2 was decreased at 30P (p=0.008), 60P (p=0.003), and 120P (p=0.002) relative to BL. ConclusionsThe pro-inflammatory response to muscle damage does not appear to decline at middle age when individuals are recreationally trained. However, young men showed significantly higher serum STNFR1 concentrations than middle age men. This may suggest that natural inhibitors of TNF-α decline as early as middle age.

Differences in physical aging measured by walking speed: evidence from the English Longitudinal Study of Ageing.

BackgroundPhysical functioning and mobility of older populations are of increasing interest when populations are aging. Lower body functioning such as walking is a fundamental part of many actions in daily life. Limitations in mobility threaten independent living as well as quality of life in old age. In this study we examine differences in physical aging and convert those differences into the everyday measure of single years of age.MethodsWe use the English Longitudinal Study of Ageing, which was collected biennially between 2002 and 2012. Data on physical performance, health as well as information on economics and demographics of participants were collected. Lower body performance was assessed with two timed walks at normal pace each of 8 ft (2.4 m) of survey participants aged at least 60 years. We employed growth curve models to study differences in physical aging and followed the characteristic-based age approach to illustrate those differences in single years of age.ResultsFirst, we examined walking speed of about 11,700 English individuals, and identified differences in aging trajectories by sex and other characteristics (e.g. education, occupation, regional wealth). Interestingly, higher educated and non-manual workers outperformed their counterparts for both men and women. Moreover, we transformed the differences between subpopulations into single years of age to demonstrate the magnitude of those gaps, which appear particularly high at early older ages.ConclusionsThis paper expands research on aging and physical performance. In conclusion, higher education provides an advantage in walking of up to 15 years for men and 10 years for women. Thus, enhancements in higher education have the potential to ensure better mobility and independent living in old age for a longer period.