Cardiorespiratory kinetics: comparisons between athletes with different training habits.

Purpose: Fast muscular oxygen uptake ([Formula: see text]) kinetics are limiting factors for high exercise capacities. It is hypothesized that [Formula: see text] and heart rate (HR) kinetics would be faster in individuals, performing long-distance endurance training (CONT) compared with athletes performing predominantly interval-based sports (INT).

Methods: 17 subjects (INT: n = 7, 24 ± 5 years, 183 ± 7 cm, 85 ± 10 kg, 6 ± 3 h of training per week, CONT: n = 10, 37 ± 7 years, 175 ± 9 cm, 69 ± 10 kg, 6 ± 3 h of training per week) completed a treadmill work rate (WR) protocol with pseudo-randomized WR changes with velocities of 6.

Structure of executive functions in young and in older persons.

Introduction: Using factor analysis, several studies reported that higher-order cognitive control involves separable executive functions. However, the number and definition of the purported functions differed between studies. One possible explanation for this discrepancy is that executive functions don't exhibit a clear factorial structure, i.

Comparison of different breath-by-breath gas exchange algorithms using a gas exchange simulation system.

Background: Mechanical Gas Exchange Simulation Systems (GESS) have never been used to compare different breath-by-breath oxygen uptake calculation algorithms.

Methods: Oxygen uptakes were calculated for each GESS cycle by the "Expiration-only" algorithm (estimating inspiratory volume from the expiratory one), and by two "alveolar" algorithms (both processing inspiratory and expiratory flows and designed to account for the changes in lung gas stores). The volume of oxygen stored in the GESS from one cycle to the subsequent one was either maintained constant or increased/decreased by changing the pumped gas volumes.

Cardiovascular regulation: associations between exercise and head-up tilt.

It was hypothesized that faster cardiorespiratory kinetics during exercise are associated with higher orthostatic tolerance. Cardiorespiratory kinetics of 14 healthy male subjects (30 ± 4 years, 179 ± 8 cm, 79 ± 8 kg) were tested on a cycle ergometer during exercise with changing work rates of 30 and 80 W. Pulmonary oxygen uptake ( ) was measured breath-by-breath and heart rate (HR), mean arterial blood pressure (MAP), and total peripheral resistance (TPR) were measured beat-to-beat.

Ecological validity of manual grasping movements in an everyday-like grocery shopping task.

In our earlier research, kinematic and kinetic parameters of grasping differed significantly when participants grasped the same object once in a traditional laboratory paradigm, and once as part of a captivating computer game. We attributed this finding to the fact that grasping movements in the laboratory were repetitive and meaningless, while those in the computer game were embedded in complex behavior and served a meaningful purpose. In that work, we argued that grasping in the computer game is more characteristic of everyday life behavior; however, this conclusion has been criticized on the grounds that a computer game is not a typical everyday activity.

Unconscious Semantic Priming Influences Performance of Visuomotor Tasks Differently but the Effects are Similar in Young and Older Adults.

We examined the effects of semantic priming of attention on two sequentially presented visuomotor tasks, traffic judgments and saccadic adaptation. Priming was accomplished with the scrambled sentence task: participants formed meaningful sentences from a list of words where a word denoting wide attention focus was involved. The results showed that semantic priming influenced positively saccade adaptation (its' benefit increased) while it attenuated visuomotor performance in the traffic task (RT of hand movements increased).

Look at that-the positive effect of video observation on physical stair climbing performance.

To examine the effect of short-term video presentation intervention (VPI) on stair self-efficacy and on stair-climbing ability, 90 participants age 65 and above were randomly assigned to 3 groups: The first intervention group watched role models descending the same staircase used for testing, the second intervention group watched role models descending an unfamiliar staircase, and the control group watched an irrelevant control video. This study found that stair-climbing duration was shortened compared with the pretest without affecting movement fluency as supported by the social-cognitive theory. We interpret this outcome as evidence for improved self-efficacy: the intervention strengthened our participants' belief that they can successfully complete the task.

Bubble Formation in Children and Adolescents after Two Standardised Shallow Dives.

Circulating venous bubbles after dives are associated with symptoms of decompression sickness in adults. Up to now it is not known to what extent children and adolescents are subjected to a bubble formation during their shallow dives and if there are possible indications for that. The aim of this pilot study is to investigate whether bubbles and/or symptoms occur after standardised repeated dives performed by young divers.

Impact of venous return on pulmonary oxygen uptake kinetics during dynamic exercise: in silico time series analyses from muscles to lungs.

The aim of the present study was to investigate whether a single-compartment (SCM) and a multi-compartment (MCM) venous return model will produce significantly different time-delaying and distortive effects on pulmonary oxygen uptake (V̇o) responses with equal cardiac outputs (Q̇) and muscle oxygen uptake (V̇o) inputs. For each model, 64 data sets were simulated with alternating Q̇ and V̇o kinetics-time constants (τ) ranging from 10 to 80 s-as responses to pseudorandom binary sequence work rate (WR) changes. Kinetic analyses were performed by using cross-correlation functions (CCFs) between WR with V̇o and V̇o.

Exercise Testing in Sports Medicine.

Background: Bicycle and treadmill exercise tests are used in sports medicine and occupational medicine to detect latent disease, to monitor treatment, and to measure patients' physical performance ability and reserve. In this review, we describe the indications, contraindications, and manner of performance of these tests, along with the variables tested, criteria for evaluation, (sub)maximal stress, and the factors that affect these tests, including age, sex, and medications.

Methods: This review is based on pertinent articles retrieved by a selective literature search and on the ergometry guidelines of four medical specialty societies.

Multitasking During Simulated Car Driving: A Comparison of Young and Older Persons.

Human multitasking is typically studied by repeatedly presenting two tasks, either sequentially (task switch paradigms) or overlapping in time (dual-task paradigms). This is different from everyday life, which typically presents an ever-changing sequence of many different tasks. Realistic multitasking therefore requires an ongoing orchestration of task switching and dual-tasking.

Impact of 60 days of 6° head down tilt bed rest on muscular oxygen uptake and heart rate kinetics: efficacy of a reactive sledge jump countermeasure.

Purpose: The effects of 60 days of head down tilt bed rest (HDBR) with and without the application of a reactive jump countermeasure were investigated, using a method which enables to discriminate between pulmonary ([Formula: see text]Opulm) and muscular ([Formula: see text]Omusc) oxygen uptake kinetics to control for hemodynamic influences.

Methods: 22 subjects were randomly allocated to either a group performing a reactive jumps countermeasure (JUMP; n = 11, male, 29 ± 7 years, 23.9 ± 1.

Temporal dissociation between muscle and pulmonary oxygen uptake kinetics: influences of perfusion dynamics and arteriovenous oxygen concentration differences in muscles and lungs.

Purpose: The aim of the study was to test whether or not the arteriovenous oxygen concentration difference (avDO) kinetics at the pulmonary (avDOpulm) and muscle (avDOmusc) levels is significantly different during dynamic exercise.

Methods: A re-analysis involving six publications dealing with kinetic analysis was utilized with an overall sample size of 69 participants. All studies comprised an identical pseudorandom binary sequence work rate (WR) protocol-WR changes between 30 and 80 W-to analyze the kinetic responses of pulmonary ([Formula: see text]) and muscle ([Formula: see text]) oxygen uptake kinetics as well as those of avDOpulm and avDOmusc.

The habitual motor vertical of humans depends on gravicentric and egocentric cues, but only little on visual cues.

Many studies have evaluated the interplay of gravicentric, egocentric, and visual cues for our perception of the vertical, but little is known about their interplay for motor control. Thirty-five participants flipped a switch "down" in experimental conditions which systematically varied body posture (upright; tilted 45° left-ear-down), visually indicated vertical (absent; aligned with the long body axis; rotated 45° counterclockwise with respect to the long body axis), and egocentric tactile information provided by a handhold (absent; present). Since we were interested in the participants' habitual rather than an instructed motor vertical, we did not specify which cues they should rely on.

Cognitive-Motor Interference in an Ecologically Valid Street Crossing Scenario.

Laboratory-based research revealed that gait involves higher cognitive processes, leading to performance impairments when executed with a concurrent loading task. Deficits are especially pronounced in older adults. Theoretical approaches like the multiple resource model highlight the role of task similarity and associated attention distribution problems.

Can Driving-Simulator Training Enhance Visual Attention, Cognition, and Physical Functioning in Older Adults?

Virtual reality offers a good possibility for the implementation of real-life tasks in a laboratory-based training or testing scenario. Thus, a computerized training in a driving simulator offers an ecological valid training approach. Visual attention had an influence on driving performance, so we used the reverse approach to test the influence of a driving training on visual attention and executive functions.

Non-invasive estimation of muscle oxygen uptake kinetics with pseudorandom binary sequence and step exercise responses.

Purpose: The aim of the study was to test for significant differences in non-invasively estimated muscle oxygen uptake ([Formula: see text]) kinetics, assessed by a square-wave exercise protocol (STEP) as well as by a time series approach with pseudorandom binary sequence (PRBS) work rate (WR) changes.

Methods: Seventeen healthy and active individuals (10 women, 7 men; 23 ± 2 years old; height 175 ± 11 cm; body mass 73 ± 14 kg [mean ± SD]) completed five repetitions of WR transitions from 30 to 80 W for the STEP approach and two sequences of pseudorandom binary WR changes between 30 and 80 W for the PRBS approach. Pulmonary oxygen uptake ([Formula: see text]) was measured breath by breath.

Interplay of Gravicentric, Egocentric, and Visual Cues About the Vertical in the Control of Arm Movement Direction.

Our perception of the vertical corresponds to the weighted sum of gravicentric, egocentric, and visual cues. Here we evaluate the interplay of those cues not for the perceived but rather for the motor vertical. Participants were asked to flip an omnidirectional switch down while their egocentric vertical was dissociated from their visual-gravicentric vertical.

Effect of Pulmonary Rehabilitation on Inspiratory Capacity During 6-min Walk Test in Patients With COPD: A PROSPECTIVE CONTROLLED STUDY.

Purpose: Purpose of this study was to analyze the impact of a pulmonary rehabilitation (PR) program on the measured inspiratory capacity (IC) in patients with chronic obstructive pulmonary disease (COPD) while performing a 6-min walk test (6MWT).

Methods: Before and after PR, IC was measured by spirometry both at the beginning and at the end of the 6MWT for 15 patients with COPD in the PR group (PRG) and compared with a similar calisthenics training group (CTG; n = 15). In addition, the COPD Assessment Test (CAT), St George's Respiratory Questionnaire (SGRQ), and other lung function tests were recorded and compared.

Motor imagery of body movements that can't be executed on Earth.

Background: Before participating in a space mission, astronauts undergo parabolic-flight and underwater training to facilitate their subsequent adaptation to weightlessness. A quick, simple and inexpensive alternative could be training by motor imagery (MI).

Objective: An important prerequisite for this training approach is that humans are able to imagine movements which are unfamiliar, since they can't be performed in the presence of gravity.

Oxygen uptake kinetics following six weeks of interval and continuous endurance exercise training - An explorative pilot study.

Purpose: The aim of the study was to compare the responses of pulmonary (V˙Opulm) and muscle (V˙Omusc) oxygen uptake kinetics before (PRE) and after (POST) six weeks of endurance exercise training.

Methods: Nine untrained individuals performed pseudo-random binary sequences work rate changes between 30W and 80W at PRE and POST training intervention. Heart rate (HR) and V˙Opulm were measured beat-to-beat and breath-by-breath, respectively.

Properties of intermodal transfer after dual visuo- and auditory-motor adaptation.

Previous work documented that sensorimotor adaptation transfers between sensory modalities: When subjects adapt with one arm to a visuomotor distortion while responding to visual targets, they also appear to be adapted when they are subsequently tested with auditory targets. Vice versa, when they adapt to an auditory-motor distortion while pointing to auditory targets, they appear to be adapted when they are subsequently tested with visual targets. Therefore, it was concluded that visuomotor as well as auditory-motor adaptation use the same adaptation mechanism.

Strength Training for Women as a Vehicle for Health Promotion at Work.

Background: Women, on average, have less muscle strength than men. This anthropometric-physiological trait may make them more vulnerable to ex - cessive physical strain, injury, and inability to work. Strength training is used for preventive health maintenance and to lessen musculoskeletal symptoms.

Effect of acute ambient temperature exposure on cardio-pulmonary and respiratory kinetics in men.

Aim: The goal of the study was to compare the kinetic responses of heart rate (HR) and pulmonary (V̇Opulm) and muscular (V̇Omusc) oxygen uptake during dynamic leg exercise across different acute ambient temperature conditions in a climatic chamber.

Methods: Thirteen physically healthy, active, male volunteers demonstrated pseudorandom binary sequence (PRBS) work rate (WR) changes between 30 and 80 W at 15 °C, 25 °C and 35 °C, respectively. HR was measured beat-to-beat using an echocardiogram and V̇Opulm by breath-by-breath gas exchange; V̇Omusc estimations were assessed by applying a circulatory model and cross-correlation functions.

Heart Rate and Oxygen Uptake Kinetics in Type 2 Diabetes Patients - A Pilot Study on the Influence of Cardiovascular Medication on Regulatory Processes.

The aim of this pilot study was to investigate whether there are differences in heart rate and oxygen uptake kinetics in type 2 diabetes patients, considering their cardiovascular medication. It was hypothesized that cardiovascular medication would affect heart rate and oxygen uptake kinetics and that this could be detected using a standardized exercise test. 18 subjects were tested for maximal oxygen uptake.