Jacob E Earp

University of Connecticut | UConn

The primary purpose of this investigation was to evaluate the influence of a whole body compression garment on recovery from a typical heavy resistance training workout in resistance-trained men and women. Eleven men (mean +/- SD: age, 23.0 +/- 2.9 years) and 9 women (mean +/- SD: age 23.1 +/- 2.2 years) who were highly resistance trained gave info...

Previous studies have reported inhomogeneous changes in quadriceps femoris (QF) cross-sectional area (CSA) in response to strength training. It is assumed that these differential changes in muscle shape influence the muscle's functional capacity during high-force and high-power movements. The purpose of the current study was to compare inter- and i...

Introduction: Tendon dynamics influence movement performance and provide the stimulus for long-term tendon adaptation. As tendon strain increases with load magnitude and decreases with loading rate, changes in movement speed during exercise should influence tendon strain. Methods: Ten resistance-trained men [squat one repetition maximum (1RM) to bo...

Purpose: The influence of external loading on muscle and tendon dynamics during maximal vertical jumping was explored. Methods: Ten resistance-trained men performed parallel-depth, countermovement vertical jumps with and without additional load (0%, 30%, 60% and 90% of maximum squat lift strength), while joint kinetics and kinematics, quadriceps...

Introduction Cold-water immersion (CWI) is often used to promote recovery by reducing exercise-induced muscle damage, soreness, and inflammation. However, recent reports have cautioned that CWI may attenuate the adaptive response to resistance training. Purpose To determine the effect of post resistance-exercise CWI on circulating free testosteron...

Rehbein, CO, McDougle, JM, Peñailillo, L, and Earp, JE. Intramuscular hamstring stiffness affects anatomically modeled localized muscle strain during passive hip flexion. J Strength Cond Res XX(X): 000–000, 2024—Hamstring strain injuries occur when localized tissue strain capacity is exceeded. Localized strain may be affected by intramuscular varia...

Passive hamstring stiffness varies proximo‐distally, resulting in inhomogeneous tissue strain during stretching that may affect localized adaptations and risk of muscle injuries. The purpose of the present study was to determine the acute and chronic effects of static stretching (SS) on intramuscular hamstring stiffness. Thirty healthy active parti...

Older athletes can train into late age with slow declines in performance, in the absence of limiting health conditions or injuries. Muscle mass and strength tend to decline along with cardiorespiratory function; some decreases may be related to older adults’ choice of activities in addition to physiologic changes, and partially reversible with targ...

Background: The activity profiles of football players during competition can be affected by the athletes’ competitive level and sex. However, evidence of this in youth South American athletes is scarce as is the effects of body composition on match activity profiles. Therefore, the present study compared the activity profiles of Chilean under-20 (U...

Valvular heart disease, including calcific or degenerative aortic stenosis (AS), is increasingly prevalent among the older adult population. Over the last few decades, treatment of severe AS has been revolutionised following the development of transcatheter aortic valve replacement (TAVR). Despite improvements in outcomes, older adults with competi...

Background Telomere attrition may share common biological mechanisms with bone and muscle loss with aging. Here, we investigated the association between these hallmarks of aging using data from UK Biobank, a large observational study. Methods Leukocyte telomere length (LTL as T/S ratio) was measured using a multiplex qPCR assay at baseline (2006–2...

Introduction This study examined the relationship between fat distribution and diabetes by sex-specific racial/ethnic groups. Methods A secondary data analysis of National Health and Nutrition Examination Survey 2011–2018 data (n = 11,972) was completed. Key variables examined were visceral adipose tissue area (VATA), subcutaneous fat area (SFA),...

Valdes, O, Inzulza, S, Collao, N, Garcia-Vicencio, S, Tufano, JJ, Earp, J, Venegas, M, and Peñ ailillo, L. Eccentric cycling is an alternative to Nordic hamstring exercise to increase the neuromuscular function of knee flexors in untrained men. J Strength Cond Res 37(11): 2158-2166, 2023-Nordic hamstring exercise (NHE) has been proposed to reduce k...

Purpose: To determine whether kinetic chain pattern during knee extensor strength training influences quadriceps femoris center of mass and moment of inertia about the hip in a predictable manner as such changes can affect running economy. Methods: Twelve participants completed 8 weeks of both unilateral open (OKC) and closed (CKC) kinetic chain re...

Background and Aims: Abdominal adiposity indices have stronger associations with cardiometabolic risk factors compared to anthropometric measures but are rarely used in large scale studies due to the cost and efficiency. The aim of this study is to establish sex and race/ethnicity specific reference equations using anthropometric measures. Method...

For individuals with Parkinson’s disease (PD), dietary habits affect disease symptoms, progression, and overall health. Protein consumption is of great interest because of the direct and indirect effects of specific amino acids (AAs) on disease progression and interference with levodopa medication. Proteins comprise 20 distinct AAs with varying eff...

The purpose of this study was to examine demographic-specific relationships between direct abdominal fat measures and anthropometric indices. A cross-sectional study was conducted utilizing abdominal fat measures (visceral fat area, VFA; visceral to subcutaneous adipose area ratio, VSR) and anthropometrics (body mass index, BMI; waist circumference...

Despite the rising awareness of abdominal adiposity associated health problems and demographic health disparities, research is lacking about abdominal fat trends using a national representative sample of US adults. Our purpose was to examine national demographic specific abdominal fat composition and distribution trends from 2011 to 2018. This tren...

This study aimed to examine the relationship of physical activity and/or dietary quality and diabetes prevalence in the general population and within specific age groups. It was a cross-sectional study using 2011–2018 National Health and Nutrition Examination Survey and the US Department of Agriculture’s Food Patterns Equivalents data (n = 15,674)....

This study examined the relationship of physical activity (PA) and dietary quality to android fat composition and distribution using a national representative adult sample and determined sex-based differences in these relationships. It is a cross-sectional (n = 10,014) analysis of the 2011–2018 National Health and Nutrition Examination Survey and t...

Acute increases in tendon blood flow and oxygenation after stress (i.e. hyperemic response) can enhance tendon recovery. While loading intensity is a fundamental part of resistance training programs, its effects on tendon’s hyperemic response are unknown. This study aimed to compare acute changes in total (THb) and oxygenated hemoglobin (HbO2) conc...

Background: Exercise-associated muscle damage (EAMD) temporally impairs muscle function and intramuscular glycogen storage. Contrast with compression (CwC) therapy provides localized EAMD treatment with minimal changes in core/tissue temperature that can impair glycogen resynthesis. Hypothesis: CwC will enhance the recovery of strength, power, a...

Hatfield, DL, Stranieri, AM, Vincent, LM, and Earp, JE. Effect of a neoprene knee sleeve on performance and muscle activity in men and women during high-intensity, high-volume resistance training. J Strength Cond Res XX(X): 000-000, 2021-The purpose of this study was to assess the effects of a commercially available neoprene knee sleeve (KS) on exe...

Earp, JE, Stearns, RL, Agostinucci, J, Lepley, AS, and Ward-Ritacco, CL. Total body and extracellular water measures are unrelated to cramp sensitivity in euhydrated cramp-prone individuals. J Strength Cond Res XX(X): 000-000, 2020-Spectral bioelectrical impedance analysis (BIA) is a valid and noninvasive tool for measuring total body water (TBW),...

Objective: This study aimed to investigate the relationships among physical activity (PA), diet quality, body composition, and fat distribution in a representative sample of US adults. Methods: A cross‐sectional analysis was conducted using publicly accessible data from the 2011 to 2016 National Health and Nutrition Examination Survey and the Food...

Background: Although dietary protein and physical activity play essential roles in developing and preserving lean mass, studies exploring these relationships are inconsistent, and large-scale studies on sources of protein and lean mass are lacking. Accordingly, the present study examined the relationship between total protein intake, protein source...

Background/objectives: The longitudinal effect of abdominal weight status (AWS) defined by waist circumference (WC) on healthy aging has not yet been comprehensively examined. Therefore, the purpose of the present study was to examine the temporal association between WC-defined AWS and a comprehensive assessment for healthy aging. Subjects/method...

BACKGROUND There is a need to assess longitudinal trends in physical function and to understand the prevalence of physical function status in the older population using objectively measured physical function. Therefore, the primary purpose of this study was to examine longitudinal sex‐specific physical function trends and prevalence of physical fun...

Purpose Health-related quality of life (HRQoL) is an important indicator of population health, yet no age-specific trend analyses in HRQoL have been conducted with a nationally representative sample since 2004. Therefore, to address this gap, an age-specific trend analysis of HRQoL was conducted using National Health and Nutrition Examination Surve...

Introduction: Recent investigations have questioned the role of hydration and electrolytes in cramp susceptibility and thus the efficacy of consuming electrolyte-rich beverages (EB) to control/prevent cramping. Methods: Nine euhydrated, cramp-prone participants had their cramp susceptibility assessed by measuring the nerve stimulation threshold...

Despite the health benefits associated with physical activity (PA), screen time reduction, and sleep quantity and quality, the relationships between PA, screen time, and sleep quantity and quality remain unclear in adolescents. The present study is a cross-sectional analysis of data from adolescents aged 16–19 years who participated in the 2005–200...

Angelino, D, McCabe, TJG, and Earp, JE. Comparing acceleration and change of direction ability between backpedal and cross-over run techniques for use in American football. J Strength Cond Res XX(X): 000-000, 2018-In American football, defensive backs guard receivers using either cross-over (CO) run or backpedal (BP) techniques, but the efficacy of...

Both high-load strength training and high-velocity power training are effective means of increasing vertical jump height. However, only strength training is able to elicit increases in tendon stiffness. Because a stiffer tendon will require more force to adequately lengthen it and will recoil at a greater velocity when lengthened changes in tendon...

Neuromuscular activation during and chronic adaptation from exercise are innately linked and both can vary along a muscle's length. During high-force and high-speed exercise intramuscular hypertrophy follows set patterns that provide the greatest biomechanical advantages. However it's unknown if muscle activity as recorded by surface electromyograp...

Astrocytes are brain cells that store and transport energy to neurons in the form of glucose. When glucose levels are low or absent, fat is metabolized and ketone bodies are created as an alternative energy source. In recent years, alternative dieting strategies such as low carbohydrate/high fat and intermittent fasting have become popular. Interes...

Purpose: To quantify the skin temperature changes following intense exercise in warm‐weather. Methods: Anterior thermal images and gastrointestinal temperature (TGI) from 20 male runners (mean±SD; 73.5 ± 10.9 kg) participating in a 11.2 km road race were collected before and immediately after the race. Wet‐bulb globe temperature (WBGT) and wind spe...

Tendon stiffness increases as the magnitude and rate of loading increases, according to its viscoelastic properties. Thus, under some loading conditions tendons should become exceptionally stiff and act almost as rigid force transducers. Nonetheless, observations of tendon behavior during multi-joint sprinting and jumping tasks have shown that tend...

Unlabelled: Compared to soy, whey protein is higher in leucine, absorbed quicker and results in a more pronounced increase in muscle protein synthesis. Objective: To determine whether supplementation with whey promotes greater increases in muscle mass compared to soy or carbohydrate, we randomized non-resistance-trained men and women into groups...

The proper selection of equipment is vital to the ability to accurately measure and track changes in performance. When measuring sprint time, electronic timing systems are recommended but may contain significant errors when an arm or leg passes through a gate before the torso. Dual-photocell (DP) and signal processing systems have been developed to...

The purpose of this study was to verify the concurrent validity of a bar-mounted Myotest® instrument in measuring the force and power production in the squat and bench press exercises when compared to the gold standard of a computerized linear transducer and force platform system. Fifty-four men (bench press: 39-171 kg; squat: 75-221 kg) and 43 wom...

Previous research has highlighted the importance of muscle and tendon structure to stretch shortening cycle performance. However, the relationships between muscle and tendon structure to performance are highly dependent on the speed and intensity of the movement. The purpose of this study was to determine if muscle and tendon structure is associate...

MEDICINE BALL EXERCISES CAN BE AN IMPORTANT TOOL IN THE DEVELOPMENT OF MUSCULATURE THAT IS IMPORTANT FOR SPORTS PERFORMANCE. MEDICINE BALL EXERCISES CAN ACHIEVE ANGULAR SPECIFICITY AND STIMULATE TISSUES THAT MAY NOT BE ACTIVATED IN EXERCISE MOVEMENTS USED IN A TYPICAL STRENGTH AND CONDITIONING PROGRAM. MEDICINE BALL TRAINING ALLOWS COMPLEX SPORT-SP...

Bower, ME, Kraemer, WJ, Potteiger, JA, Volek, JS, Hatfield, DA, Vingren, JL, Spiering, BA, Fragala, MS, Ho, JY, Thomas, GA, Earp, JE, Häkkinen, K, and Maresh, CM. Relationship between off-ice testing variables and on-ice speed in women's collegiate synchronized figure skaters: implications for traning. J Strength Cond Res 24(3): 831-839, 2010-The p...

The purpose of this study was to examine the relationship between lower-body muscle structure and vertical jump performance. Twenty-five resistance-trained men (age, 23.3 +/- 3.2 years; height, 176.1 +/- 7.4 cm; and weight, 86.2 +/- 11.6 kg) took part in both anatomical and jump performance testing. Muscle fascicle thickness, fascicle length, and p...

Migiano, MJ, Vingren, JL, Volek, JS, Maresh, CM, Fragala, MS, Ho, J-Y, Thomas, GA, Hatfield, DL, Häkkinen, K, Ahtiainen J, Earp, JE, and Kraemer WJ. Endocrine response patterns to acute unilateral and bilateral resistance exercise in men. J Strength Cond Res 24(1): 128-134, 2010-Rehabilitation programs and research experiments use single-arm protoc...

Rehabilitation programs and research experiments use single-arm protocols in which the contralateral arm is not functional or used as a control limb. This study was interested in determining the hormonal signal impacts of such one- versus two-arm exercise responses that might have an impact on adaptational changes with training. The purpose was to...

The purpose of the current investigation was to identify any existing relationships between off-ice performance measures and on-ice performance quantified by speed and acceleration. Twenty-seven women (age 1961 year; body mass (59.5±6.8 kg; height 164.6±6.35 cm; body fat 23.2 ± 3.9%) who were collegiate synchronized figure skaters volunteered for t...