The utility of the reperfusion rate of tissue oxygen saturation as a measure of vascular endothelial function in adolescents: reliability, validity and sensitivity.

The near-infrared spectroscopy (NIRS)-derived reperfusion rate of tissue oxygen saturation (slope 2 StO) may provide a surrogate measure of vascular function, however, this has yet to be examined in a paediatric population. This study investigated in adolescents: 1) the between-day reliability of NIRS-derived measurements; 2) the relationship between slope 2 StO and macro- (flow-mediated dilation, FMD) and microvascular (peak reactive hyperaemia, PRH) function; and 3) the effect of high-intensity interval exercise (HIIE) on slope 2 StO, FMD, and PRH. Nineteen boys (13.

The effect of 4 weeks of high-intensity interval training and 2 weeks of detraining on cardiovascular disease risk factors in male adolescents.

New Findings: What is the central question of this study? What is the effect of 4 weeks of high-intensity interval training (HIIT) and 2 weeks of detraining on vascular function and traditional cardiovascular disease (CVD) risk factors in male adolescents? What is the main finding and its importance? Four weeks of HIIT improved macrovascular function in adolescents. However, this training period did not measurably change microvascular function, body composition or blood biomarkers. Following 2 weeks of detraining, the improvement in flow-mediated dilatation (FMD) was lost.

Highly Cushioned Shoes Improve Running Performance in Both the Absence and Presence of Muscle Damage.

Purpose: We tested the hypotheses that a highly cushioned running shoe (HCS) would 1) improve incremental exercise performance and reduce the oxygen cost (Oc) of submaximal running, and 2) attenuate the deterioration in Oc elicited by muscle damage consequent to a downhill run.

Methods: Thirty-two recreationally active participants completed an incremental treadmill test in an HCS and a control running shoe (CON) for the determination of Oc and maximal performance. Subsequently, participants were pair matched and randomly assigned to one of the two footwear conditions to perform a moderate-intensity running bout before and 48 h after a 30-min downhill run designed to elicit muscle damage.

Steady-state [Formula: see text] above MLSS: evidence that critical speed better represents maximal metabolic steady state in well-trained runners.

The metabolic boundary separating the heavy-intensity and severe-intensity exercise domains is of scientific and practical interest but there is controversy concerning whether the maximal lactate steady state (MLSS) or critical power (synonymous with critical speed, CS) better represents this boundary. We measured the running speeds at MLSS and CS and investigated their ability to discriminate speeds at which [Formula: see text] was stable over time from speeds at which a steady-state [Formula: see text] could not be established. Ten well-trained male distance runners completed 9-12 constant-speed treadmill tests, including 3-5 runs of up to 30-min duration for the assessment of MLSS and at least 4 runs performed to the limit of tolerance for assessment of CS.

Effects of High-Intensity Interval Training on the Vascular and Autonomic Components of the Baroreflex at Rest in Adolescents.

Purpose: In a sample of healthy adolescents, the authors aimed to investigate the effects of high-intensity interval exercise (HIIE) training and detraining on baroreflex sensitivity (BRS) and it's vascular and autonomic components at rest.

Methods: Nineteen volunteers were randomly allocated to (1) 4 weeks HIIE training performed 3 times per week or (2) a control condition with no intervention for the same duration as HIIE training. PRE, POST, and following 2 weeks of detraining resting supine heart rate and blood pressure were measured, and a cross-spectral method (integrated gain [gain in low frequency]) was used to determine BRS gain.

The acute effect of high- and moderate-intensity interval exercise on vascular function before and after a glucose challenge in adolescents.

New Findings: What is the central question of this study? What is the effect of high-intensity and moderate-intensity interval running on macro- and microvascular function in a fasted state and following a glucose challenge in adolescents? What is the main finding and its importance? Both macro- and microvascular function were improved after interval running independent of intensity. This finding shows that the intermittent exercise pattern and its associated effect on shear are important for vascular benefits. In adolescents, macrovascular function was enhanced after an acute glucose load.

Effects of exercise intensity on vascular and autonomic components of the baroreflex following glucose ingestion in adolescents.

Purpose: To investigate the effects of an oral glucose tolerance test (OGTT) on baroreflex sensitivity (BRS) in a sample of healthy adolescents, and how acute exercise bouts of different intensities alter the effects of the OGTT on BRS.

Methods: Thirteen male adolescents (14.0 ± 0.

Reliability of low-flow vasoreactivity in the brachial artery of adolescents.

Purpose: Macrovascular endothelial function is commonly assessed using flow-mediated dilation (FMD) and is nitric oxide (NO) dependent. However, the vasoreactivity to low flow during the FMD protocol may complement FMD interpretation. This study aimed to investigate in adolescents: (1) the day-to-day reliability of low-flow-mediated constriction (L-FMC) and composite vessel reactivity (CVR); and (2) the relationship between L-FMC and FMD.