The effect of critical speed and exercise intensity on stroke phase duration and bilateral asymmetry in 200-m front crawl swimming.

The main aim of this study was to determine the absolute temporal relationship between the power and recovery phases of the stroke cycle in front crawl swimming in response to progressive changes in exercise intensity that occurred before and after critical speed. A second objective was to determine whether intensity-related changes in the power/recovery phase relationship affects the bilateral symmetry of the stroke. Stroke parameters were recorded for each 25-m length during a progressive 200-m interval training set, in which eight (2 males, 6 females) national-level swimmers swam at intensities below, above, and at critical speed.

The response of persons with chronic nonspecific low back pain to three different volumes of periodized musculoskeletal rehabilitation.

Chronic nonspecific low back pain (CLBP) is a common musculoskeletal health issue associated with pain and disability reduced quality of life (QoL). Pain initiates a fear-avoidance cycle, which needs to be broken if rehabilitation is to work. To break this cycle, exercise must be gradual and focused on strengthening the weakened musculature.

The influence of periodized resistance training on strength changes in men and women.

The purpose of this study was to contrast the response of previously resistance-trained male and female recreational athletes with a traditionally periodized resistance training program. Sixty subjects (age = 22.8 ± 4.

A comparison of traditional and weekly undulating periodized strength training programs with total volume and intensity equated.

The purpose of this study was to compare the training adaptations attained during 12 weeks of traditional (TD) and weekly undulating (WUD) periodized strength training. Forty-two recreationally active men (age = 22 ± 2.3 years) were randomly assigned to 1 of 3 groups: control (C) (n = 14), TD (n = 14), or WUD (n = 14).

The influence of periodized resistance training on recreationally active males with chronic nonspecific low back pain.

The most common musculoskeletal health issue is chronic nonspecific low back pain (CLBP). CLBP increases pain and disability, which reduces quality of life (QoL). Generally, pain, disability, and QoL are improved with a moderate volume and intensity of physical activity.

A comparison of two forms of periodized exercise rehabilitation programs in the management of chronic nonspecific low-back pain.

The purpose of this study was to determine the influence of 2 different periodized exercise rehabilitation programs (resistance training [RT] and aerobic training [AT]) on musculoskeletal health, body composition, pain, disability, and quality of life (QOL) in chronic (>or=3 months; >or=3 d.wk) nonspecific low-back pain (CLBP) persons. Twenty-seven CLBP subjects were randomly assigned to 1 of 3 groups, 1) RT (n = 9), 2) AT (n = 9), or 3) control (C; n = 9).

Relationships between stroke parameters and critical swimming speed in a sprint interval training set.

The aim of this study was to determine whether a relationship exists between stroke parameters and critical swimming speed (which is defined as the speed that can theoretically be maintained without exhaustion). Stroke parameters (stroke rate and length) and velocity were recorded for each 25-m length during a controlled sprint interval training set in which participants swam one of the four competitive strokes at a range of intensities below, at, and above critical speed. Eleven participants (8 females, 3 males; age 17.

Relationship between erector spinae muscle oxygenation via in vivo near infrared spectroscopy and static endurance time in healthy males.

The purpose of the study was to confirm the trends in right and left side muscle blood volume (Mbv) and muscle oxygenation (Mox) during the Biering-Sorensen muscular endurance (BSME) test, compare right and left side Mbv and Mox responses, and predict BSME time via Mox variables. Research suggests that during moderate intensity (approximately 20% of maximal volitional contraction) muscle contraction blood flow will decrease as a result of increased intramuscular pressure. Moreover, decreased muscle oxygenation is believed to be associated with diminished musculoskeletal endurance time, but until the development of near infrared spectroscopy (NIRS) it was not possible to non-invasively monitor these changes in erector spinae muscle.

The spirit of sport, morality, and hypoxic tents: logic and authenticity.

The World Anti-Doping Agency (WADA) has recently made a decision to allow the use of hypoxic tents amid a significant amount of controversy over the morality of their use for athletic training purposes. Currently, altitude training is considered moral, but other means of improving aerobic performance are not; for example, blood doping. Altitude training and blood doping have similar results, but the methods by which the results are achieved differ greatly.

In vivo erector spinae muscle blood volume and oxygenation measures during repetitive incremental lifting and lowering in chronic low back pain participants.

Study Design: A case control study.

Objectives: Using metabolic gas analysis and near infrared spectroscopy, a comparison was made between healthy controls and chronic low back pain (LBP) participants on cardiorespiratory, erector spinae muscle blood volume, and oxygenation responses, and these variables were used to determine factors that best predict peak oxygen consumption (VO2peak).

Summary Of Background Data: To date, it is unknown how the cardiorespiratory and erector spinae muscles of chronic LBP persons respond to repetitive incremental lifting and lowering.

Relationship between erector spinae static endurance and muscle oxygenation-blood volume changes in healthy and low back pain subjects.

The purposes of this study were to: (1) compare the muscle blood volume (Mbv) and oxygenation (Mox) responses on the right and left side erector spinae during the Biering-Sorensen muscle endurance (BSME) test between healthy, low back pain active (LBP-A) and LBP-sedentary (LBP-S) subjects using near infrared spectroscopy (NIRS), and (2) determine the relationships between the BSME time and Mbv and Mox. Informed consent was obtained from 30 healthy and 30 chronic LBP subjects. The latter group was subdivided into an active (LBP-A; n = 18) and sedentary (LBP-S; n = 12) subgroups based on physical activity patterns.

Reliability of erector spinae oxygenation and blood volume responses using near-infrared spectroscopy in healthy males.

The purpose of this investigation was to (1). describe the trends in oxygenation (OXY) and blood volume (BV) of the right and left paraspinal muscles during the Biering-Sorensen muscle endurance (BSME) test using near infrared spectroscopy (NIRS), and (2). assess the test-retest reliability of OXY and BV changes during the BSME in healthy males.

Cardiorespiratory and hemodynamic responses during repetitive incremental lifting and lowering in healthy males and females.

The purposes of this study were twofold. First, to evaluate the cardiorespiratory and muscle oxygenation (OXY)/blood volume (BV) responses during repetitive incremental lifting and lowering (RILL) in healthy males and females. Second, to develop a predictive equation for predicting peak aerobic power (VO(2peak)) during RILL from the cardiorespiratory, OXY/BV and body composition variables.

Impact of beta-blocker treatment on the prognostic value of currently used risk predictors in congestive heart failure.

Objectives: This prospective study tested the impact of beta-blocker treatment on currently used risk predictors in congestive heart failure (CHF).

Background: Given the survival benefit obtained by beta-blockade, risk stratification by factors established in the "pre-beta-blocker era" may be questioned.

Methods: The study included 408 patients who had CHF with left ventricular ejection fraction (LVEF) <45%, all treated with an angiotensin-converting enzyme inhibitor or angiotensin type 1 receptor antagonist, who were classified into those receiving a beta-blocker (n = 165) and those who were not (n = 243).