Comparison of Training, Anthropometric, Physiological and Psychological Variables of Ultra-Endurance Cyclists and Runners

AbstractWe compared training, anthropometric, physiological and psychological characteristics between 14 cyclists, participants in a 24-hour mountain bike race and 12 runners, participants in a 7-day running ultra-marathon. Methods: Questionnaires and physiological measurements. Results: The differences in ages between cyclists and runners were significant (p << 0.01). The pre-race minus post-race differences (Δ) in body mass (from 76.5 ± 13.1kg to 72.0 ± 12.0kg) and (Δ) in value of hematocrit (6.1 ± 3.5%) were significant only in runners. The post-race minus pre-race difference (Δ) in the rating of perceived exertion was significant in both groups

The Influence of Visual and Somatosensory Input on the Vestibulo-Oculomotor Reflex of Pigmented Rats

Eye movements were recorded in the pigmented rat during vestibular, optokinetic and combined visual-vestibular stimulation. The dominant time constant in pigmented rats, tested during angular vestibular stimulation in darkness, is about two times longer than the cupular time constant. The gain and the duration of nystagmus, achieved by angular vestibular stimulation, can be enhanced by visual impulses. This is most evident during an optokinetic temporonasal stimulation, but is also seen with a nasotemporal stimulation. A mere optokinetic monocular stimulation without a synchronous vestibular excitation causes nystagmus only when the stimuli has a temporonasal direction. The duration of nystagmus, achieved by angular vestibular stimulation, is prolonged by disturbances of the neck proprioceptive system. This is more evident during a simultaneous visual input than in darkness. The ability to cancel nystagmus during conflicting vestibular and optokinetic impulses is well developed in the pigmented rat.</jats:p

Normal-hearing and hearing-impaired subjects' ability to just follow conversation in competing speech, reversed speech, and noise backgrounds

The performance on a conversation-following task by 24 hearing-impaired persons was compared with that of 24 matched controls with normal hearing in the presence of three background noises: (a) speech-spectrum random noise, (b) a male voice, and (c) the male voice played in reverse. The subjects' task was to readjust the sound level of a female voice (signal), every time the signal voice was attenuated, to the subjective level at which it was just possible to understand what was being said. To assess the benefit of lipreading, half of the material was presented audiovisually and half auditorily only. It was predicted that background speech would have a greater masking effect than reversed speech, which would in turn have a lesser masking effect than random noise. It was predicted that hearing-impaired subjects would perform more poorly than the normal-hearing controls in a background of speech. The influence of lipreading was expected to be constant across groups and conditions. The results showed that the hearing-impaired subjects were equally affected by the three background noises and that normal-hearing persons were less affected by the background speech than by noise. The performance of the normal-hearing persons was superior to that of the hearing-impaired subjects. The prediction about lipreading was confirmed. The results were explained in terms of the reduced temporal resolution by the hearing-impaired subjects.</p

Otoneurological findings in workers exposed to styrene.

An otoneurological test battery was administered to 18 workers with long-term exposure (6-15 years) to styrene at levels well below the current Swedish limit (110 mg/m3). The results were compared with those of a reference group. Disturbances were found in the central auditory pathways of seven workers. Tests reflecting central processing of impulses from different sensory equilibrium organs were abnormal for 16 workers. The most relevant tests seemed to be static posturography and the rotatory visual suppression test. In the posturography the styrene group had a significantly larger sway area than the reference group. In the visual suppression test, the styrene workers displayed a significantly poorer ability to suppress vestibular nystagmus than the reference group. It was concluded that styrene exposure in industrial environments at moderate or low levels causes central nervous system disturbances which are not always diagnosable with psychometric tests but can be apparent in special otoneurological tests.</p

Audiological and Vestibulo-Oculomotor Findings in Workers Exposed to Solvents and Jet Fuel

Three groups of subjects with long-term (5-41 years) occupational exposure to industrial solvents have been evaluated with extensive audiological and vestibular test batteries. Group A comprised 16 subjects with a confirmed diagnosis of psycho-organic syndrome (POS), while group B consisted of 7 subjects with suspected POS. Both groups had been exposed to mixtures of aliphatic and aromatic solvents. Eight subjects with long-term exposure to jet fuel constituted group C. In the audiological test battery, discrimination of interrupted speech and evoked cortical potentials in response to frequency glides were the tests that yielded significantly abnormal results. In the vestibular test battery, considerable pathology was seen in electronystagmography, and in addition, visual suppression test and saccade test indicated CNS disturbance. In general, when a test yielded pathological results, the incidence of pathology was highest in group A and lowest in group C.</p