Biofeedback control of skin potential level

This study explored the possibility of using biofeedback to arrest spontaneous declines in tonic electrodermal levels. For 3 days, 10 subjects(S) received 20 minutes of training in increasing skin potential level (SPL) negativity (arrested declines), followed by 20 minutes of training in decreasing SPL negativity (facilitating declines), with reverse order for half of theSs. Simultaneous analogue and binary feedback of SPL were used. Training in the direction of SPL increases resulted in arrest of spontaneous declines in SPL negativity but did not result in large-magnitude increases above baseline. Training in the direction of SPL decreases facilitated declines in SPL. The absolute mean difference between the increase condition and the decrease condition on the 3rd day was 8.28 mV. Correlations suggested that considerable intraindividual variability may have been independently related to the Locus of Control personality dimension and to a Law of Initial Values limitation on SPL change. It was concluded that SPL was controllable to the extent of facilitating or arresting spontaneous declines.     

Strength cycle training: effects on muscular strength and aerobic conditioning

The strength cycle ergometer has been proposed as a method of simultaneously increasing aerobic conditioning and muscular strength, because of its unique capacity of disengaging the pedal crank, thus allowing for concurrent single-leg cycling. The purpose of this study was to assess the aerobic and muscular strength effects of strength cycle training (SCT), comparing it to similar standard cycle training. A total of 28 recreationally-trained adult subjects (9 men, 19 women) were paired for VO2peak and randomly assigned to either SCT or Monark cycle training (MCT). Subjects trained 3 days per week following a progressive interval protocol for 9 weeks under supervised conditions. Training intervals (5 minutes' duration) consisted of 3 minutes of standard cycling at an intensity of 60-85% of maximum heart rate (HRmax), and 2 minutes of either the disengaged cycling mode (SCT) or standard cycling plus 30 W (MCT). Subjects began training for a total of 25 minutes per session, progressing to 45 minutes per session by study's end. Prior to and following training, subjects were measured for VO2peak; submaximal VO2, heart rate (HR), RPE, power output, and knee and ankle isokinetic strength. Training resulted in significant (p < or = 0.05) increases in VO2peak (14.5%) and submaximal power output (11%), and significant reductions in submaximal VO2, HR, and RPE in both groups. Significant increases in bilateral isokinetic knee extension (4-6%) and left ankle plantar flexion (10.5%) were noted following training in both groups. No group differences were detected in any variable. Although the strength cycle effectively increased aerobic function and resulted in modest selected increases in lower-extremity muscular strength, these changes were not different from those seen using a similar standard cycling protocol.     

Effects of biofeedback on the discrimination of electrodermal activity

Twenty-four subjects were tested on their ability to discriminate between the presence and absence of negative skin potential responses before and after training to control skin potential. Training consisted of 52 discrete 30-second trials during which subjects were asked either to increase or to inhibit palmar sweating. Subjects in groups N and P were provided with analogue feedback on their skin potential activity. Group N was correctly informed that increases in sweating were indicated by increases in the negativity of skin potential; group P was misinformed that these were indicated by increases in the positivity of skin potential. Subjects in the control (C) group received no feedback. Reliable evidence of discrimination was obtained only in groups N and P, following training. However, reliable evidence of control was obtained only in group N. Thus, training to control skin potential led to an ability to identify afferentation associated with the more common (i.e., negative) skin potential responses, even though biofeedback training appeared unsuccessful in the case of group P. These findings are discussed in the context of "discrimination" or "awareness" accounts of the process of acquiring control of internal response.     

Effects of a Longitudinal Training Program on Responses to Exercise in Overweight Men

Objective: The aim of this study was to determine how training modifies metabolic responses and lipid oxidation in overweight young male subjects. Research Methods and Procedures: Eleven overweight subjects were selected for a 4‐month endurance training program. Before and after the training period, they cycled for 60 minutes at 50% of their Vo ₂max after an overnight fast or 3 hours after eating a standardized meal. Various metabolic and endocrine parameters, and respiratory exchange ratio values were evaluated. Results: Exercise‐induced plasma norepinephrine concentration increases were similar before and after training in fasted or fed conditions. After food intake, exercise promoted a decrease in plasma glucose and a higher increase in epinephrine than in fasting conditions. The increase in epinephrine after the meal was more marked after training (264 ± 32 vs. 195 ± 35 pg/mL). Training lowered the resting plasma nonesterified fatty acids. During exercise, changes in glycerol were similar to those found before training. Lipid oxidation during exercise was higher in fasting than in fed conditions (15.5 ± 1.4 vs. 22.3 ± 1.7 g/h). Training did not significantly increase fat oxidation when exercise was performed in fed conditions, but it did in fasting conditions (18.6 ± 1.4 vs. 27.2 ± 1.8 g/h). Discussion: Endurance training decreased plasma nonesterified fatty acids, cholesterol, and insulin concentrations. Training increased lipid oxidation during exercise, in fasting conditions, and not when exercise was performed after the meal. During exercise in overweight subjects, the fasting condition seems more suited to oxidizing fat and maintaining glucose homeostasis than a 3‐hour wait after a standard meal.     

Effects of streptozotocin-induced diabetes and physical training on gene expression of extracellular matrix proteins in mouse skeletal muscle

Diabetes induces changes in the structure and function of the extracellular matrix (ECM) in many tissues. We investigated the effects of diabetes, physical training, and their combination on the gene expression of ECM proteins in skeletal muscle. Mice were divided to control (C), training (T), streptozotocin-induced diabetic (D), and diabetic training (DT) groups. Training groups (T, DT) performed 1, 3, or 5 wk of endurance training on a treadmill. Gene expression of calf muscles was analyzed using microarray and quantitative PCR. Training group samples were collected 24 h after the last training session. Diabetes affected the gene expression of several collagens (types I, III, IV, V, VI, and XV), some noncollagenous glycoproteins, and proteoglycans (e.g., elastin, thrombospondin-1, laminin-2, decorin). Reduced gene expression of collagens in diabetic skeletal muscle was partially attenuated as a result of physical training. In diabetes, mRNA expression of the basement membrane (BM) collagens decreased and that of noncollagenous glycoproteins increased. This may change the structure of the BM in a less collagenous direction and affect its properties.     

The effects of training in hyperoxia vs. normoxia on skeletal muscle enzyme activities and exercise performance.

Inspiring a hyperoxic (H) gas permits subjects to exercise at higher power outputs while training, but there is controversy as to whether this improves skeletal muscle oxidative capacity, maximal O(2) consumption (Vo(2 max)), and endurance performance to a greater extent than training in normoxia (N). To determine whether the higher power output during H training leads to a greater increase in these parameters, nine recreationally active subjects were randomly assigned in a single-blind fashion to train in H (60% O(2)) or N for 6 wk (3 sessions/wk of 10 x 4 min at 90% Vo(2 max)). Training heart rate (HR) was maintained during the study by increasing power output. After at least 6 wk of detraining, a second 6-wk training protocol was completed with the other breathing condition. Vo(2 max) and cycle time to exhaustion at 90% of pretraining Vo(2 max) were tested in room air pre- and posttraining. Muscle biopsies were sampled pre- and posttraining for citrate synthase (CS), beta-hydroxyacyl-coenzyme A dehydrogenase (beta-HAD), and mitochondrial aspartate aminotransferase (m-AsAT) activity measurements. Training power outputs were 8% higher (17 W) in H vs. N. However, both conditions produced similar improvements in Vo(2 max) (11-12%); time to exhaustion (approximately 100%); and CS (H, 30%; N, 32%), beta-HAD (H, 23%; N, 21%), and m-AsAT (H, 21%; N, 26%) activities. We conclude that the additional training stimulus provided by training in H was not sufficient to produce greater increases in the aerobic capacity of skeletal muscle and whole body Vo(2 max) and exercise performance compared with training in N.     

Developmental trends of theta–beta interelectrode power correlation during resting state in normal children

The possibility that power-to-power (theta–beta) frequency coupling increases during development was analyzed. Three minutes of spontaneous EEG in an open eyes condition were recorded in a sample of 160 subjects ranging from 6 to 26 years old. Theta (4–7 Hz) and beta band (15–20 Hz) power was calculated in a trial-by-trial basis. Inter-electrode power correlations (IPC) were computed in each subject as the correlation between the power of two frequency bands recorded in two electrodes. An increase in theta–beta IPC with age was obtained. IPCs were higher when theta was seeded in posterior regions than in anterior or central regions. Moreover, the significant correlations between each individual IPC and age were calculated, making it possible to draw IPC versus age correlation maps in order to capture the IPC development topography. An increase was found in significant correlations in the left hemisphere compared to the right hemisphere. There were no differences in the inter-hemispheric versus intra-hemispheric IPC maturation spatial patterns. An increase in power-to-power–frequency coupling in theta–beta occurs during development, suggesting an increase in functional connectivity with age. Frequency coupling between theta and beta rhythms would be one of the mechanisms facilitating integration of long distance functional networks during development.     

Training with unilateral resistance exercise increases contralateral strength.

Evidence that unilateral training increases contralateral strength is inconsistent, possibly because existing studies have design limitations such as lack of control groups, lack of randomization, and insufficient statistical power. This study sought to determine whether unilateral resistance training increases contralateral strength. Subjects (n = 115) were randomly assigned to a control group or one of the following four training groups that performed supervised elbow flexion contractions: 1) one set at high speed, 2) one set at low speed, 3) three sets at high speed, or 4) three sets at low speed. Training was 3 times/wk for 6 wk with a six- to eight-repetition maximum load. Control subjects attended sessions but did not exercise. Elbow flexor strength was measured with a one-repetition maximum arm curl before and after training. Training with one set at slow speed did not produce an increase in contralateral strength (mean effect of -1% or -0.07 kg; 95% confidence interval: -0.42-0.28 kg; P = 0.68). However, three sets increased strength of the untrained arm by a mean of 7% of initial strength (additional mean effect of 0.41 kg; 95% confidence interval: 0.06-0.75 kg; P = 0.022). There was a tendency for training with fast contractions to produce a greater increase in contralateral strength than slow training (additional mean effect of 5% or 0.31 kg; 95% confidence interval: -0.03-0.66 kg; P = 0.08), but there was no interaction between the number of sets and training speed. We conclude that three sets of unilateral resistance exercise produce small contralateral increases in strength.     

Echo SPL, training experience, and experimental procedure influence the ranging performance in the big brown bat, Eptesicus fuscus

Four Eptesicus fuscus were trained in a range discrimination experiment to choose the closer of two phantom targets. Echo attenuation was roving between trials returning echoes ranging from −10 dB to −50 dB SPL (sound pressure level) relative to emission SPL. Discrimination thresholds were determined. After sufficient training, ranging performance was stable and about the same in the range between −20 dB and −50 dB with range difference thresholds around 300 μs. At −10 dB, performance was poor even after long training. After additional training at a constant relative echo SPL of −30 dB and a delay difference of 300 μs the performance measured with roving echo SPL improved at all relative echo SPL between −20 dB and −50 dB but not at −10 dB. The new experimental procedure improved the performance by additional learning, and the bats generalized over a wide range of relative echo SPL. Threshold improved to 100 μs when measured at a constant relative echo SPL of −30 dB, again indicating the influence of the experimental procedure. In correspondence to neurophysiological data the ranging performance deteriorates if the echo SPL is close to the emission SPL. Signal duration and emission SPL were variable during range discrimination. Accepted: 7 March 1998     

Attenuation of age-related declines in glucagon-mediated signal transduction in rat liver by exercise training

This study investigated alterations in glucagon receptor-mediated signal transduction in rat livers from 7- to 25-mo-old animals and examined the effects of exercise training on ameliorating these changes. Sixty-six young (4 mo), middle-aged (12 mo), and old (22 mo) male Fischer 344 rats were divided into sedentary and trained (treadmill running) groups. Isolated hepatic membranes were combined with [(125)I-Tyr(10)]monoiodoglucagon and nine concentrations of glucagon to determine maximal binding capacity (B(max)) and dissociation constant (K(d)). No alterations were found in B(max) among groups; however, middle-aged trained animals had significantly higher glucagon affinity (lower K(d); 21.1 +/- 1.8 nM) than did their untrained counterparts (50.2 +/- 7.1 nM). Second messenger studies were performed by measuring adenylyl cyclase (AC) specific activity under basal conditions and with four pharmacological stimulations to assess changes in receptor-dependent, G protein-dependent, and AC catalyst-dependent cAMP production. Age-related declines were observed in the old animals under all five conditions. Training resulted in increased cAMP production in the old animals when AC was directly stimulated by forskolin. Stimulatory G protein (G(s)) content was reduced with age in the sedentary group; however, training offset this decline. We conclude that age-related declines in glucagon signaling capacity and responsiveness may be attributed, in part, to declines in intrinsic AC activity and changes in G protein [inhibitory G protein (G(i))/G(s)] ratios. These age-related changes occur in the absence of alterations in glucagon receptor content and appear to involve both G protein- and AC-related changes. Endurance training was able to significantly offset these declines through restoration of the G(i)/G(s) ratio and AC activity.     

Improving Sprint Performance in Soccer: Effectiveness of Jump Squat and Olympic Push Press Exercises

Training at the optimum power load (OPL) is an effective way to improve neuromuscular abilities of highly trained athletes. The purpose of this study was to test the effects of training using the jump squat (JS) or Olympic push-press (OPP) exercises at the OPL during a short-term preseason on speed-power related abilities in high-level under-20 soccer players. The players were divided into two training groups: JS group (JSG) and OPP group (OPPG). Both groups undertook 12 power-oriented sessions, using solely JS or OPP exercises. Pre- and post-6 weeks of training, athletes performed squat jump (SJ), countermovement jump (CMJ), sprinting speed (5, 10, 20 and 30 m), change of direction (COD) and speed tests. To calculate the transfer effect coefficient (TEC) between JS and MPP OPP and the speed in 5, 10, 20, and 30 m, the ratio between the result gain (effect size [ES]) in the untrained exercise and result gain in the trained exercise was calculated. Magnitude based inference and ES were used to test the meaningful effects. The TEC between JS and VEL 5, 10, 20, and 30 m ranged from 0.77 to 1.29, while the only TEC which could be calculated between OPP and VEL 5 was rather low (0.2). In addition, the training effects of JS on jumping and speed related abilities were superior (ES ranging from small to large) to those caused by OPP (trivial ES). To conclude, the JS exercise is superior to the OPP for improving speed-power abilities in elite young soccer players.     

Effects of High-Intensity Interval Training versus Continuous Training on Physical Fitness,Cardiovascular Function and Quality of Life in Heart Failure Patients

Introduction

Physical fitness is an important prognostic factor in heart failure (HF). To improve fitness, different types of exercise have been explored, with recent focus on high-intensity interval training (HIT). We comprehensively compared effects of HIT versus continuous training (CT) in HF patients NYHA II-III on physical fitness, cardiovascular function and structure, and quality of life, and hypothesize that HIT leads to superior improvements compared to CT.

Methods

Twenty HF patients (male:female 19:1, 64±8 yrs, ejection fraction 38±6%) were allocated to 12-weeks of HIT (10*1-minute at 90% maximal workload—alternated by 2.5 minutes at 30% maximal workload) or CT (30 minutes at 60–75% of maximal workload). Before and after intervention, we examined physical fitness (incremental cycling test), cardiac function and structure (echocardiography), vascular function and structure (ultrasound) and quality of life (SF-36, Minnesota living with HF questionnaire (MLHFQ)).

Results

Training improved maximal workload, peak oxygen uptake (VO_2peak) related to the predicted VO_2peak, oxygen uptake at the anaerobic threshold, and maximal oxygen pulse (all P<0.05), whilst no differences were present between HIT and CT (N.S.). We found no major changes in resting cardiovascular function and structure. SF-36 physical function score improved after training (P<0.05), whilst SF-36 total score and MLHFQ did not change after training (N.S.).

Conclusion

Training induced significant improvements in parameters of physical fitness, although no evidence for superiority of HIT over CT was demonstrated. No major effect of training was found on cardiovascular structure and function or quality of life in HF patients NYHA II-III.

Trial Registration

Nederlands Trial Register NTR3671     

Effects of biofeedback on the discrimination of electrodermal activity

Twenty-four subjects were tested on their ability to discriminate between the presence and absence of negative skin potential responses before and after training to control skin potential. Training consisted of 52 discrete 30-second trials during which subjects were asked either to increase or to inhibit palmar sweating. Subjects in groups N and P were provided with analogue feedback on their skin potential activity. Group N was correctly informed that increases in sweating were indicated by increases in the negativity of skin potential; group P was misinformed that these were indicated by increases in the positivity of skin potential. Subjects in the control (C) group received no feedback. Reliable evidence of discrimination was obtained only in groups N and P, following training. However, reliable evidence of control was obtained only in group N. Thus, training to control skin potential led to an ability to identify afferentation associated with the more common (i.e., negative) skin potential responses, even though biofeedback training appeared unsuccessful in the case of group P. These findings are discussed in the context of discrimination or awareness accounts of the process of acquiring control of internal responses.This work was supported by grants from York University and from Glendon College.     

Interaction between concurrent strength and endurance training

To assess the effects of concurrent strength (S) and endurance (E) training on S and E development, one group (4 young men and 4 young women) trained one leg for S and the other leg for S and E (S+E). A second group (4 men, 4 women) trained one leg for E and the other leg for E and S (E+S). E training consisted of five 3-min bouts on a cycle ergometer at a power output corresponding to that requiring 90-100% of oxygen uptake during maximal exercise (VO2 max). S training consisted of six sets of 15-20 repetitions with the heaviest possible weight on a leg press (combined hip and knee extension) weight machine. Training was done 3 days/wk for 22 wk. Needle biopsy samples from vastus lateralis were taken before and after training and were examined for histochemical, biochemical, and ultrastructural adaptations. The nominal S and E training programs were "hybrids", having more similarities as training stimuli than differences; thus S made increases (P less than 0.05) similar to those of S+E in E-related measures of VO2max (S, S+E: 8%, 8%), repetitions with the pretraining maximal single leg press lift [1 repetition maximum (RM)] (27%, 24%), and percent of slow-twitch fibers (15%, 8%); and S made significant, although smaller, increases in repetitions with 80% 1 RM (81%, 152%) and citrate synthase (CS) activity (22%, 51%). Similarly, E increased knee extensor area [computed tomography (CT) scans] as much as E+S (14%, 21%) and made significant, although smaller, increases in leg press 1 RM (20%, 34%) and thigh girth (3.4%, 4.8%). When a presumably stronger stimulus for an adaptation was added to a weaker one, some additive effects occurred (i.e., increases in 1 RM and thigh girth that were greater in E+S than E; increases in CS activity and repetitions with 80% 1 RM that were greater in S+E than S). When a weaker, although effective, stimulus was added to a stronger one, addition generally did not occur. Concurrent S and E training did not interfere with S or E development in comparison to S or E training alone.     

Age-related immunosenescence in Fischer 344 rats: influence of exercise training.

The present investigation examined the extent to which 15 wk of endurance training could influence immune function in young, middle-aged, and older animals. Forty-eight male Fischer 344 rats were divided into trained and untrained groups. Training consisted of treadmill running at 75% maximal running capacity for 1 h/day, 5 days/wk, for 15 wk. Animals were killed at 8, 17, and 27 mo, at which time splenocytes were isolated. The capacity for lymphocyte proliferation in response to mitogen (concanavalin A, ConA), interleukin-2 (IL-2) production, and cytolytic activity against YAC-1 target cells was determined. ConA-induced proliferation declined significantly with age. Training suppressed the proliferative response in the young (-41%) and middle-aged animals (-27%) compared with the age-matched controls; however, training improved this response (+58%) in the older group. IL-2 production followed a pattern similar to that for mitogen-induced proliferation, such that production declined with age and was reduced with training in young and middle-aged animals but was significantly more improved in the older animals than in age-matched controls. The ability to lyse target cells, measured as percent cytotoxicity, declined steadily with advancing age at all effector-to-target cell ratios tested: 52, 14, and -16% for 8-, 17-, and 27-mo-old rats, respectively. It was concluded that the capacity for ConA-induced splenocyte proliferation, IL-2 production, and cytolytic activity declines significantly with advancing age. Furthermore, 15 wk of endurance training suppressed proliferation and IL-2 production in young animals but improved these responses in older animals. Training had no effect on cytolytic activity.     

S1P lyase regulates DNA damage responses through a novel sphingolipid feedback mechanism

The injurious consequences of ionizing radiation (IR) to normal human cells and the acquired radioresistance of cancer cells represent limitations to cancer radiotherapy. IR induces DNA damage response pathways that orchestrate cell cycle arrest, DNA repair or apoptosis such that irradiated cells are either repaired or eliminated. Concomitantly and independent of DNA damage, IR activates acid sphingomyelinase (ASMase), which generates ceramide, thereby promoting radiation-induced apoptosis. However, ceramide can also be metabolized to sphingosine-1-phosphate (S1P), which acts paradoxically as a radioprotectant. Thus, sphingolipid metabolism represents a radiosensitivity pivot point, a notion supported by genetic evidence in IR-resistant cancer cells. S1P lyase (SPL) catalyzes the irreversible degradation of S1P in the final step of sphingolipid metabolism. We show that SPL modulates the kinetics of DNA repair, speed of recovery from G2 cell cycle arrest and the extent of apoptosis after IR. SPL acts through a novel feedback mechanism that amplifies stress-induced ceramide accumulation, and downregulation/inhibition of either SPL or ASMase prevents premature cell cycle progression and mitotic death. Further, oral administration of an SPL inhibitor to mice prolonged their survival after exposure to a lethal dose of total body IR. Our findings reveal SPL to be a regulator of ASMase, the G2 checkpoint and DNA repair and a novel target for radioprotection.     

Specificity of joint angle in isometric training

Six healthy women (21.8 +/- 0.4 y) did isometric strength training of the left plantarflexors at an ankle joint angle of 90 degrees. Training sessions, done 3 times per week for 6 weeks, consisted of 2 sets of ten 5 s maximal voluntary contractions. Prior to and following the training, and in random order, voluntary and evoked isometric contraction strength was measured at the training angle and at additional angles: 5 degrees, 10 degrees, 15 degrees, and 20 degrees intervals in the plantarflexion and dorsiflexion directions. Evoked contraction strength was measured as the peak torque of maximal twitch contractions of triceps surae. Training increased voluntary strength at the training angle and the two adjacent angles only (p less than 0.05). Time to peak twitch torque was not affected by training. Twitch half relaxation time increased after training (p = 0.013), but the increase was not specific to the training angle. There was a small (1.1%, p less than 0.05) increase in calf circumference after training. Evoked twitch torque did not increase significantly at any joint angle. It was therefore concluded that a neural mechanism is responsible for the specificity of joint angle observed in isometric training.     

Triiodothyronine deiodinating activity in brown adipose tissue after short cold stimulation test in trained and untrained rats

Interscapular brown adipose tissue (IBAT) activity is controlled by sympathetic nervous system, and factors that influence thermogenesis appear to be centrally connected to the sympathetic outflow to IBAT. Cold exposure produces a rise in BAT temperature, which is associated with an increased thyroid activity, elevated serum levels of 3,5,3'-triiodothyronine (T3), and an increased rate of T3 production. This study evaluated the effect of swimming training on 5'-triiodothyronine deiodinase (5'-D) activity in IBAT under normal environmental conditions and after short (30 min) cold exposure (TST stimulation test). 5'-D activity is lower in trained rats at basal condition, and TST increases 5'-D in IBAT of both untrained and trained rats. However, this increase is lower in trained rats. Training reduces the deiodinating activity in normal environmental conditions as well as after short cold exposure. Probably, other compensatory mechanisms of heat production are active in trained rodents.     

Changes in skeletal muscle in males and females following endurance training

Gender differences in substrate selection have been reported during endurance exercise. To date, no studies have looked at muscle enzyme adaptations following endurance exercise training in both genders. We investigated the effect of a 7-week endurance exercise training program on the activity of beta-oxidation, tricarboxylic acid cycle and electron transport chain enzymes, and fiber type distribution in males and females. Training resulted in an increase in VO2peak, for both males and females of 17% and 22%, respectively (P < 0.001). The following muscle enzyme activities increased similarly in both genders: 3-beta-hydroxyacyl CoA dehydrogenase (38%), citrate synthase (41%), succinate-cytochrome c oxidoreductase (41%), and cytochrome c oxidase (COX; 26%). The increase in COX activity was correlated (R2 = 0.52, P < 0.05) with the increase in VO2peak/fat free mass. Fiber area, size, and % area were not affected by training for either gender, however, males had larger Type II fibers (P < 0.05) and females had a greater Type I fiber % area (P < 0.05). Endurance training resulted in similar increases in skeletal muscle oxidative potential for both males and females. Training did not affect fiber type distribution or size in either gender.     

The effects of ten weeks of resistance and combined plyometric/sprint training with the Meridian Elyte athletic shoe on muscular performance in women

The purpose of this investigation was to examine the combined effects of resistance and sprint/plyometric training with or without the Meridian Elyte athletic shoe on muscular performance in women. Fourteen resistance-trained women were randomly assigned to one of 2 training groups: (a) an athletic shoe (N = 6) (AS) group or (b) the Meridian Elyte (N = 8) (MS) group. Training was performed for 10 weeks and consisted of resistance training for 2 days per week and 2 days per week of sprint/plyometric training. Linear periodized resistance training consisted of 5 exercises per workout (4 lower body, 1 upper body) for 3 sets of 3-12 repetition maximum (RM). Sprint/plyometric training consisted of 5-7 exercises per workout (4-5 plyometric exercises, 40-yd and 60-yd sprints) for 3-6 sets with gradually increasing volume (8 weeks) followed by a 2-week taper phase. Assessments for 1RM squat and bench press, vertical jump, broad jump, sprint speed, and body composition were performed before and following the 10-week training period. Significant increases were observed in both AS and MS groups in 1RM squat (12.0 vs. 14.6 kg), bench press (6.8 vs. 7.4 kg), vertical jump height (3.3 vs. 2.3 cm), and broad jump (17.8 vs. 15.2 cm). Similar decreases in peak 20-, 40-, and 60-m sprint times were observed in both groups (20 m: 0.14 vs. 0.11 seconds; 40 m: 0.29 vs. 0.34 seconds; 60 m: 0.45 vs. 0.46 seconds in AS and MS groups, respectively). However, when sprint endurance (the difference between the fastest and slowest sprint trials) was analyzed, there was a significantly greater improvement at 60 m in the MS group. These results indicated that similar improvements in peak sprint speed and jumping ability were observed following 10 weeks of training with either shoe. However, high-intensity sprint endurance at 60 m increased to a greater extent during training with the Meridian Elyte athletic shoe.