Time-varying analysis of electrodermal activity during exercise.

The electrodermal activity (EDA) is a useful tool for assessing skin sympathetic nervous activity. Using spectral analysis of EDA data at rest, we have previously found that the spectral band which is the most sensitive to central sympathetic control is largely confined to 0.045 to 0.

Case Study: Impact of Inter- and Intra-Day Energy Parameters on Bone Health, Menstrual Function, and Hormones in an Elite Junior Female Triathlete.

This observational case study examined the association of inter- and intraday energy intake and exercise energy expenditure with bone health, menstrual status and hematological factors in a female triathlete. The study spanned 7 months whereby energy intake and exercise energy expenditure were monitored three times (13 d); 16 blood samples were taken, urinary hormones were assessed for 3 months, and bone mineral density was measured twice. Energy availability tended to be sustained below 30 kcal/kg FFM/d and intraday energy intake patterns were often "back-loaded" with approximately 46% of energy consumed after 6 p.

Ovarian suppression impairs sport performance in junior elite female swimmers.

Introduction: Competitive female athletes restrict energy intake and increase exercise energy expenditure frequently resulting in ovarian suppression. The purpose of this study was to determine the impact of ovarian suppression and energy deficit on swimming performance (400-m swim velocity).

Methods: Menstrual status was determined by circulating estradiol (E2) and progesterone (P4) in ten junior elite female swimmers (15-17 yr).

Elevated PYY is associated with energy deficiency and indices of subclinical disordered eating in exercising women with hypothalamic amenorrhea.

The purpose of this study was twofold: (1) to determine if gastrointestinal hormones, associated with energy intake and energy balance, are altered in exercising women with hypothalamic amenorrhea and (2) to assess the association between gastrointestinal hormones and behavioural indicators of subclinical disordered eating in exercising women with hypothalamic amenorrhea. This cross-sectional study analyzed serum ghrelin, peptide YY (PYY), glucagon-like peptide-1 (GLP-1), menstrual status (by E1G and PdG), resting energy expenditure (REE), and subclinical eating behaviours in sedentary ovulatory (SedOv), exercising ovulatory (ExOv), and exercising amenorrheic (ExAmen) women. Groups were similar with respect to age (23.

Short-term response of bone turnover to low-dose oral contraceptives in exercising women with hypothalamic amenorrhea.

Background: We examined the response of bone turnover markers and indices of energy status after 2 weeks of oral contraceptive (OC) therapy in premenopausal women with exercise-associated menstrual disturbances (EAMD).

Study Design: Six women with EAMD received one 28-day cycle of a triphasic OC containing 180-250 mcg norgestimate/25 mcg ethinyl estradiol (EAMD+OC) and six were controls (EAMD controls). Bone turnover markers amino-terminal propeptide of Type I procollagen and serum carboxy-terminal telopeptides of Type I collagen (PINP and SCTX-I) were assessed at baseline and after 2 weeks of OC therapy (EAMD+OC) or after a 30-day monitoring period (EAMD controls).

Female athletes: factors impacting successful performance.

Competitive female athletes face many challenges unlike their recreationally active counterparts. As sport has advanced for girls and women, the physical, psychologic, and nutritional demands force female athletes to develop optimal strategies for competitive success. Sports medicine professionals must consume volumes of research investigating issues regarding competitive female athletes.

Severity of energy-related menstrual disturbances increases in proportion to indices of energy conservation in exercising women.

Alterations in resting energy expenditure and metabolic hormones (energy conservation) are evident in increasing magnitude across a continuum of increasing severity of clinical menstrual disturbances, including luteal-phase defects, anovulation, and amenorrhea in exercising women. These data provide further evidence of the tight association between energy balance and reproduction and suggest that subtle declines in energy availability can produce clinically recognized menstrual disturbances.

Effects of chromium supplementation on glycogen synthesis after high-intensity exercise.

Purpose: Chromium enhances insulin signaling and insulin-mediated glucose uptake in cultured cells. We investigated the effect of chromium on glycogen synthesis and insulin signaling in humans.

Methods: Sixteen overweight men (BMI = 31.

Peak systolic blood pressure on a graded maximal exercise test and the blood pressure response to an acute bout of submaximal exercise.

Blood pressure (BP) is immediately reduced after aerobic exercise (postexercise hypotension [PEH]). Whether peak systolic BP on a maximal graded exercise stress test (GEST) relates to PEH is not known. This study examined associations between peak systolic BP on a GEST and PEH.

Off-ice performance and draft status of elite ice hockey players.

Purpose: The primary purpose of this study was to determine whether tests performed at the National Hockey League (NHL) Combine could distinguish draft status (ie, the round selected). A secondary aim was to provide performance ranges and percentiles for each of the dependent variables.

Methods: A retrospective, cross-sectional study design was used with performance data and draft order from 2001, 2002, and 2003 Combine participants.

Positional performance profiling of elite ice hockey players.

Purpose: The primary purpose of this study was to determine whether positional profiling is possible for elite ice hockey players by examining anthropometric characteristics and physiological performance. In addition, performance ranges and percentiles were determined for each position (forwards, defensemen, and goalkeepers) on all dependent variables.

Methods: A retrospective, cross-sectional study design was used with performance data from ice hockey players (mean age = 18.

Pituitary-adrenal responses to arm versus leg exercise in untrained man.

The purpose of this study was to examine pituitary-adrenal (PA) hormone responses [beta-endorphin (beta-END), adrenocorticotropic hormone (ACTH) and cortisol] to arm exercise (AE) and leg exercise (LE) at 60 and 80% of the muscle-group specific VO2 peak. Eight healthy untrained men (AE VO2 peak=32.4+/-3.

Androgen receptor content following heavy resistance exercise in men.

The purpose of the present investigation was to examine androgen receptor (AR) content in the vastus lateralis following two resistance exercise protocols of different volume. Nine resistance-trained men (age=24.3+/-4.

High-affinity growth hormone binding protein and acute heavy resistance exercise.

Purpose: The purpose of this investigation was to examine the influence of resistance training on circulating concentrations of growth hormone binding protein (GHBP) in response to acute heavy resistance exercise.

Methods: Using a cross-sectional experimental design, a group of resistance-trained men (RT, N=9, 7.9+/-1.

Diet and exercise for weight loss: a review of current issues.

Obesity is a fast growing epidemic that is primarily due to environmental influences. Nutrition and exercise represent modifiable factors with a major impact on energy balance. Despite considerable research, there remains continued debate regarding the energy content and the optimal macronutrient distribution for promoting healthy and effective weight loss.

Heat acclimation and physical training adaptations of young women using different contraceptive hormones.

Although endogenous and exogenous steroid hormones affect numerous physiological processes, the interactions of reproductive hormones, chronic exercise training, and heat acclimation are unknown. This investigation evaluated the responses and adaptations of 36 inactive females [age 21 +/- 3 (SD) yr] as they undertook a 7- to 8-wk program [heat acclimation and physical training (HAPT)] of indoor heat acclimation (90 min/day, 3 days/wk) and outdoor physical training (3 days/wk) while using either an oral estradiol-progestin contraceptive (ORAL, n = 15), a contraceptive injection of depot medroxyprogesterone acetate (DEPO, n = 7), or no contraceptive (EU-OV, n = 14; control). Standardized physical fitness and exercise-heat tolerance tests (36.

Assessment of linear sprinting performance: a theoretical paradigm.

The purpose of this manuscript is to describe a theoretical paradigm from which to more accurately assess linear sprinting performance. More importantly, the model describes how to interpret test results in order to pinpoint weaknesses in linear sprinting performance and design subsequent training programs. A retrospective, quasi-experimental cross sectional analysis was performed using 86 Division I female soccer and lacrosse players.

Characteristics of elite open-water swimmers.

Open-water swimming (5, 10, and 25 km) has many unique challenges that separate it from other endurance sports, like marathon running and cycling. The characteristics of a successful open-water swimmer are unclear. The purpose of this study was to determine the physical and metabolic characteristics of a group of elite-level open-water swimmers.

Body composition in Division I football players.

This study assessed body composition of Division I football players (n = 69) and compared the findings with previously reported data to ascertain whether the increase in player total body mass that has been observed over the past 10 years has been accompanied by an increase in body fat. Body composition was determined by hydrostatic weighing and the measurement of skinfold thicknesses. Total body mass, skinfold thicknesses, and body fat were greater in the current players than in players in studies conducted in the early 1980s and early 1990s.

Drinking behavior and perception of thirst in untrained women during 6 weeks of heat acclimation and outdoor training.

The purposes of this study were to characterize measures of fluid intake and perception of thirst in women over a 6-week period of exercise-heat acclimation and outdoor training and examine if this lengthy acclimation period would result in changes in fluid intake that differ from those previously reported in men utilizing a shorter acclimation protocol of 8-10 days. Voluntary water intake (11-17 degrees C) and perception of thirst were measured in a group of 5 women (21-26 yr) undergoing exercise-heat acclimation for 90 min/day, 3 days/wk (36 degrees C, rh 50-70%) and outdoor training 3 days/wk for 6 weeks. Decreased drinking during acclimation was characterized by a decrease in the number of drinks (35 +/- 10 to 17 +/- 5; p <.

Postexercise hypotension differs between white and black women.

Background: Because data are lacking, we examined the acute effect of exercise on ambulatory blood pressure (BP) in premenopausal white women (n = 18) and black women (n = 15) with normal (n = 21) and high (n = 12) BP.

Methods: Women performed 40 minutes of control and moderate-intensity exercise. BP and hormones were measured before, during, and after the control and exercise periods.

Cognitive and motor function after administration of hydrocodone bitartrate plus ibuprofen, ibuprofen alone, or placebo in healthy subjects with exercise-induced muscle damage: a randomized, repeated-dose, placebo-controlled study.

Rationale: Medications combining hydrocodone bitartrate and non-steroidal anti-inflammatory agents appear more beneficial than anti-inflammatory medications alone in treating pain and inflammation from acute soft tissue trauma, but opiate side effects may include sedation and impaired cognitive and motor performance.

Objective: Performance on complex cognitive and motor tasks was evaluated in healthy subjects with exercise-induced muscle damage who were treated with a hydrocodone-ibuprofen combination, ibuprofen alone, or placebo.

Methods: This double-blind, randomized, placebo-controlled, repeated-dose clinical trial compared the effects of hydrocodone bitartrate (7.

The unknown mechanism of the overtraining syndrome: clues from depression and psychoneuroimmunology.

When prolonged, excessive training stresses are applied concurrent with inadequate recovery, performance decrements and chronic maladaptations occur. Known as the overtraining syndrome (OTS), this complex condition afflicts a large percentage of athletes at least once during their careers. There is no objective biomarker for OTS and the underlying mechanism is unknown.