Eric Sobolewski

Verified

Eric verified their affiliation via an institutional email.

Learn more

Verified

Eric verified their affiliation via an institutional email.

Learn more

• PhD. MBA
• Professor (Associate) at Furman University

This narrative review explores the intricate relationship between circadian regulation and exercise performance, emphasizing the importance of aligning training strategies with the body’s natural physiological fluctuations. The three key mechanisms investigated are temperature, hormonal fluctuations, and diurnal chronotype—an individuals’ exhibitio...

Prior to training, many athletes perform different soft-tissue preparation protocols. Many of these protocols involve stretching, foam rolling, and/or percussion massage. Many of these modalities have been studied, but not as a group to observe muscle alterations and differences in males and females. In total, 40 (20 males, 20 females) participants...

Time Course Changes in Muscle Size and Echo Intensity Following Resistance Training

Introduction: The use of ultrasound images for analyzing muscle quality and size is continuing to grow in the literature. However, many of these manuscripts fail to properly describe their measurement techniques and steps involved in analyzing ultrasound images. Aim of this study: To evaluate the intra- and inter-rater reliability of the steps invo...

The purpose of this study was to determine the relationship between EI, CSA, and aerobic performance, and to develop a model to predict aerobic performance. Twenty aerobically trained participants had a panoramic ultrasound taken of their rectus femoris and vastus lateralis muscles on their right leg before performing a maximal aerobic cycling test...

The aim of this study is to explore the relationships between internal and external load measures in American football. Thirty football players wore a portable integrated monitor unit for 10 weeks during the fall football season. Relationships between internal and external load measurements were determined. Internal load consisted of heart rate zon...

Background The ability to maintain a submaximal force as a muscle fatigues is supplemented by compensatory adjustments in the nervous system’s control of motor units. Aim We sought to compare vastus lateralis motor unit recruitment and firing rate data for younger versus older men during isometric fatigue. Methods Twelve younger (age = 25 ± 3 yea...

Background: Declines in muscle morphology and function are commonly reported as a consequence of aging. However, few studies have investigated the influence of age on a comprehensive set of muscle function-related measures (i.e., reactive strength, power, etc.) that focuses on a dynamic performance task such as the vertical jump across the adult l...

Intro: Running economy is an important variable associated with cross-country. Not only does it serve as a measure of aerobic ability, but also it is also indicative of future race performance. Running economy can be defined as the steady state oxygen consumption (VO2) at a given velocity. Those with a lower VO2 at any given velocity are considered...

Intro: Running economy is another measure of an individual’s aerobic ability and is defined as the steady-state oxygen consumption (VO2) at a given running velocity. Individuals with high running economies can run faster at a constant speed for a given distance. The lower a person’s running economy is the less energy is required to run at that spee...

Intro: Collegiate male cross-country runners and soccer players are known to have high training loads that are more aerobic in nature. It is expected that these elite athletes have a high level of aerobic capacity in order to perform the best. Absolute VO2 is the total volume of oxygen consumed, whereas relative VO2 is the total volume of oxygen co...

Intro: Collegiate athletes undergo a large amount of mental and physical stress during their competition season. Evaluating their overall health is a beneficial way to keep track of the strain they are undergoing. Collecting this data is important for monitoring issues or noticing negative trends that are occurring within a program. By using a self...

Intro: Sleep is vital to performing daily tasks but even more important for athletes trying to recover from training. Sleep has become a high priority as a method for recovery and growth. The current recommendation for college age students is to achieve more than seven hours of sleep a night. There is very little work done on what is the minimum th...

Males and Female have shown to have different body compositions and VO2 max values. When addressing VO2 values it is beneficial to normalize to fat free mass (FFM) when comparing across groups as fat mass does not play a role in metabolism and FFM is correlated with higher VO2 values. When comparing across athletic populations it is even more impor...

Research is currently utilizing ultrasound (US) imaging to evaluate acute muscle damage from exercise. Common derived US measurements to evaluate muscle damage are: image grey scale, commonly known as echo intensity (EI), and cross sectional area (CSA). Due to limited literature, it is unclear how and to what degree extended aerobic exercise effect...

The two primary measurements involving Ultrasound Imaging used to assess changes in muscle following exercise are Echo Intensity (EI), which is the gray scale of the image and cross-sectional area (CSA). Due to limited literature, it is unclear how and to what degree muscles composition changes following aerobic exercise. Purpose: This study evalua...

The purposes of this study were to examine the age-related differences in absolute and normalized torque-time parameters in five distinct groups across the adult life span, and the relationship between rapid strength and limb acceleration capacities across the lifespan. One-hundred and thirty-six healthy men were categorized as young athletes (n =...

Purpose: The aims of this study was to determine the physiological demand of practice in National Collegiate Athletic Association Division I football players through Global positioning system, accelerometers and Heart Rate monitoring across position groups. Approach: Thirty players wore a portable integrated monitor unit for 10-weeks during the fal...

Gait speed is now recognized as an important clinical tool in the older adult population. However, fast gait speed appears to better reflect lower-extremity muscle performance and declines more rapidly in advanced age than comfortable gait speed. We examined the ability of leg lean mass and absolute and rapid strength characteristics to predict fas...

Gait speed declines with age, and has shown to be a significant predictor of mortality. Similarly, the preservation of muscle strength and lean body mass are both important for healthy aging. It is unclear, however, if both muscle strength and lean body mass explain variance gait speed in younger and older adults. Purpose: We evaluated whether leg...

Measuring physiological demands of sport is becoming increasingly easier to do with the onset of wearable technology, yet very little research has been done with NCAA college football players. Traditionally heart rate (HR) has been used to estimate caloric expenditure of exercise and has shown to be a valid measure, yet with the integration of HR m...

Heart rate (HR) and rate of perceived exertion are typically used to determine internal training load. External training loads have been derived from GPS and accelerometer data. Internal and external training loads have had moderate relations to each other based on what measures are used for each load. PURPOSE: The purpose of this study was to dete...

The ability to objectively measure intensity of football practice is commonly used as a method to determine effort during practice, training load, and recovery. Subjective measures such as rate of perceived exertion are traditionally used and with the development of technology the analysis of heart rate through heart rate variably (HRV) may have th...

Recently, an equation that allows investigators to correct echo intensity for subcutaneous fat was developed. We evaluated correlations between uncorrected and corrected echo intensity versus measures of lower-extremity function. Twenty-three older adults (11 men, 12 women; mean age = 72 y) participated. B-Mode ultrasonography was used to quantify...

Background: Reactive agility tests have become popular in sport for talent identification; however, the ability of these tests to evaluate physical function and falls risk in clinical populations warrants future study. Aim: To examine the reliability and construct validity of a novel functional reactive agility test (FRAT) across the lifespan....

This study investigated the impact of age, knee joint angle, and strength testing modality on lower body maximal and rapid strength production and assessed the transferability of these characteristics to mobility-related function. Twenty young (age=21.9 yrs) and eighteen elderly (71.1 yrs) adults performed single-joint and multiple-joint isometric...

The current understanding of age-related declines in muscle strength capacities is largely based upon strength testing at joint angles of optimal performance, but many activities of daily living involve force generation at muscle lengths/angles outside of optimal force. This study investigated the influence of age, joint angle, and muscle group (kn...

Introduction: The purpose of this study was to investigate the age-related differences in absolute and normalized plantarflexion rate of torque development (RTD) at early (0-50 ms) and late (100-200 ms) time intervals, and to examine specific neural and muscular mechanisms contributing to these differences. Methods: Thirty-two young (20.0±2.1 yr...

Objective: The present study examined the influence of workplace manual labor on measures of muscular fitness, with a secondary aim to investigate the relationship between muscular fitness and work performance in blue-collar (BC) workers. Methods: Leg extension isokinetic strength at slow and fast velocities, hamstring and hip-flexor flexibility...

Background: Physical demands may vary between white collar and blue collar occupations when evaluating specific physiological differences such as one's weight, body mass index and body fat percentage. Objective: To explore nutritional, anthropometric, and physical-activity differences between young and middle-aged WC and BC workers. Methods: N...

Achilles tendon (AT) properties change with age, however the extent to which aging influences the size of the AT may be influenced by the measurement technique. The purpose of this study was to 1) examine the age-related differences in AT size using measures of cross-sectional area (CSA) and thickness, and 2) to determine the test-retest reliabilit...

The aims of this study were to 1) examine the influence of age and occupation on maximal and rapid strength of the lower-extremity muscles and 2) examine the relationship between maximal and rapid strength and physical workload (work index (WI)) in the blue-collar (BC) cohort. Peak torque (PT) and peak rate of torque development (peakRTD) of the le...

The aim of this study was to determine the feasibility of an 8-week, home-based isometric strength training program in equestrians. Also, we examined changes in muscular strength, endurance, and riding performance. 18 riders (≥1 year dressage experience, riding ≥1 h/week, otherwise untrained) completed pre-/post-muscular tests and a US Equestrian F...

The aim of this study was to investigate the association between dietary protein (PRO) intake and maximal and rapid strength of the leg flexors in blue collar (BC) working men. Twenty-four young (age, 23.2 ± 2.1 years) and 19 older (age, 52.8 ± 5.2 years) men employed in BC occupations completed a 3-day dietary record and isometric strength testing...

The purposes of the present study were to determine the effect of Creatine (Cr) supplementation on 1) voluntary isometric and isokinetic strength and 2) active and passive range of motion (ROM) during loading and the subsequent washout period. The secondary purpose was to address any possible underlying neuromuscular mechanisms that might influence...

The reflection of an ultrasound (US) wave is strongest when the propagation direction of the wave is perpendicular to muscle fascicles. Thus, it is possible that muscle echo intensity (EI), a gray-scale US measure of muscle quality, may be influenced by the angulation of muscle fascicles. Therefore, the purpose of this study was to determine if age...

Introduction: In this study we examined the test-retest reliability of panoramic brightness-mode ultrasound (US) imaging to simultaneously measure both muscle size and quality from a single US image. Methods: Sixteen healthy, recreationally active men (age = 20.9 ± 2.5 years) volunteered for this investigation. Test-retest reliability was evalua...

Passive stretching is commonly recommended to help reduce passive stiffness in older adults, yet their acute viscoelastic stretch responses are still unclear. The purpose of this study was to determine the influence of age on the acute viscoelastic responses to a practical stretching intervention. Twenty-two younger (24±3 years) and 14 older (67±3...

The purpose of this study was to examine the acute effects of different volumes of a dynamic stretching routine on vertical jump (VJ) performance, flexibility and muscular endurance (ME). Twenty-six males (age 22·2 ± 1·3 years) performed three separate randomized conditions: (i) a control (CON) condition (5-min jog + 12 min of resting), (ii) a 5-mi...

We examined the influence of maximum range of motion (MROM) and passive stiffness on the viscoelastic stretch response. Four 30-s constant-angle passive stretches of the plantar flexors at a predetermined torque were performed to determine the rate and relative change in stress relaxation (decline in torque during each 30-s stretch) and creep (incr...

The purpose of the present study was to examine test-retest reliability and minimal detectable change (MDC) values for Achilles tendon (AT) length determined using panoramic ultrasound (US) imaging. Seventeen men (age = 21.0 ± 2.3 y) visited the laboratory on two separate days, where AT length was examined along the mid-longitudinal axis of the rig...

The purpose of the present study was to examine the relationships between absolute and body mass-normalized rapid isometric torque variables and vertical jump(VJ) performance of the leg extensors and flexors in elite National Collegiate Athletic Association (NCAA) Division I Football Bowl Subdivision (FBS) collegiate American football players. Thir...

3224 The acute physiological response to strenuous exercise is characterized by a transient hypercoagulable state as well as an acute inflammatory response. Despite these well-recognized findings, the mechanisms involved in these exercise-induced effects are not well understood. To further evaluate the effect of exercise on multiple hematologic par...

Abstract We compared starters and non-starters for various isokinetic strength variables in elite women's soccer players. A convenience sample of 10 starters (mean ± s; age = 20 ± 2 years; height = 170 ± 4 cm; body mass = 65 ± 5 kg) and 7 non-starters (age = 20 ± 1 years; height = 164 ± 3 cm; body mass = 63 ± 4 kg) performed maximal voluntary muscl...

The decline in maximal and rapid isometric torque characteristics may compromise functional living abilities in aging adults while loco-motor muscle groups, such as the leg extensors and flexors, may exhibit different torque-time age related decreases. The purpose of the present study was to examine the age-related differences in maximal and rapid...

The purpose of this study was to investigate the consistency of commonly reported rapid force characteristics utilizing both automated and manual muscle contraction onset detection methods. Twenty-four healthy volunteers performed isometric strength testing of the plantar flexor muscle group on two nonconsecutive days. Test-retest reliability was e...

The purpose of the present study was to determine if maximal and rapid isometric torque characteristics could discriminate starters from non-starters in elite Division I American collegiate football players. Sixteen starters (mean ± SD: age = 20.81 ± 1.28 years; height = 184.53 ± 6.58 cm; mass = 108.69 ± 22.16 kg) and fifteen non-starters (20.40 ±...

The purpose of the present study was to examine the effects of an acute bout of eccentric exercise on maximal isokinetic concentric peak torque (PT) of the leg flexors and extensors and the hamstrings-to-quadriceps (H:Q) strength ratio. Sixteen male (mean±SD: age=20.9±2 years; stature=177.0±4.4 cm; mass=76.8±10.0 kg) volunteers performed maximal, c...

The purpose of this study was to determine whether static stretching alone or combined with a warm-up affected isokinetic peak torque (IPT) of the quadriceps at both slow and fast velocities. Twenty physically active males (22.1 ± 2.4 years) performed maximal knee extensions under four conditions: no stretch control, stretch only, 5 min jog followe...

In 1992, Harris and colleagues demonstrated that oral creatine supplementation can enhance muscle creatine stores. Since then, creatine has become an important and popular ergogenic aid for improving athletic performance with reports of up to 74% of athletes supplementing with creatine. Although many recent studies have addressed the safety concern...

Passive stiffness measurements are often used as a clinical tool to examine a muscle's passive lengthening characteristics. The purpose of this study was to examine the relationship between passive stiffness and evoked twitch properties prior to and following normalization of passive stiffness to muscle cross-sectional area (CSA). Ten healthy volun...

Does stretching alter ankle proprioception. Ankle was passively stretched both in planter flexion and dorsi flexion for 3 x 30 sec. Then subject's ankle was then moved to a random ROM, then retruned to 90 deggrees and then subject was then asked to move their ankle to the previously given angle. Differences in given angle and subjected percievd ang...

The purposes of these studies were to determine if an acute static stretch influenced isokinetic peak torque (IPT), and to examine if the order in which the warm up routine was performed affected peak knee extension torque. Twenty trained college male students performed maximal isokinetic knee extensions under four conditions: a control consisting...