9 research outputs found
Fibre-Specific Responses to Endurance and Low Volume High Intensity Interval Training: Striking Similarities in Acute and Chronic Adaptation
The current study involved the completion of two distinct experiments. Experiment 1 compared fibre specific and whole muscle responses to acute bouts of either low-volume high-intensity interval training (LV-HIT) or moderate-intensity continuous endurance exercise (END) in a randomized crossover design. Experiment 2 examined the impact of a six-week training intervention (END or LV-HIT; 4 days/week), on whole body and skeletal muscle fibre specific markers of aerobic and anaerobic capacity. Six recreationally active men (Age: 20.7±3.8 yrs; VO2peak: 51.9±5.1 mL/kg/min) reported to the lab on two separate occasions for experiment 1. Following a muscle biopsy taken in a fasted state, participants completed an acute bout of each exercise protocol (LV-HIT: 8, 20-second intervals at ∼170% of VO2peak separated by 10 seconds of rest; END: 30 minutes at ∼65% of VO2peak), immediately followed by a muscle biopsy. Glycogen content of type I and IIA fibres was significantly (p<0.05) reduced, while p-ACC was significantly increased (p<0.05) following both protocols. Nineteen recreationally active males (n = 16) and females (n = 3) were VO2peak-matched and assigned to either the LV-HIT (n = 10; 21±2 yrs) or END (n = 9; 20.7±3.8 yrs) group for experiment 2. After 6 weeks, both training protocols induced comparable increases in aerobic capacity (END: Pre: 48.3±6.0, Mid: 51.8±6.0, Post: 55.0±6.3 mL/kg/min LV-HIT: Pre: 47.9±8.1, Mid: 50.4±7.4, Post: 54.7±7.6 mL/kg/min), fibre-type specific oxidative and glycolytic capacity, glycogen and IMTG stores, and whole-muscle capillary density. Interestingly, only LV-HIT induced greater improvements in anaerobic performance and estimated whole-muscle glycolytic capacity. These results suggest that 30 minutes of END exercise at ∼65% VO2peak or 4 minutes of LV-HIT at ∼170% VO2peak induce comparable changes in the intra-myocellular environment (glycogen content and signaling activation); correspondingly, training-induced adaptations resulting for these protocols, and other HIT and END protocols are strikingly similar
Word-Retrieval in Two Cases of Progressive Supranuclear Palsy
In this paper, we describe the detailed neuropsychological investigation of two cases of progressive supranuclear palsy (PSP) and demonstrate word-finding difficulties associated with pervasive problems in word-retrieval. The pattern of deficits resembles that seen in Parkinson’s Disease (PD) but is more severe, even in very mild PSP, and appears less amenable to cue facilitation. Performance on a variety of word-production tasks is compared, and experimental controls for motor effects on performance are included. The role of stimulus cues in speeded word-finding is addressed experimentally, as are central executive influences on task performance. This combines with functional brain-scan data from single photon emission computed tomography (SPECT) which shows reduced frontal perfusion in one of the two cases
Dissociation between speech modalities in a case of altered accent with unknown origin
We present a case of sudden onset, acquired altered accent in the speech of NL, a 48-year-old, left-handed female. NL’s typical Standard Southern British English accent was preserved in singing and reading, but altered in recitation, repetition and spontaneous speech. Neuropsychological investigation, impressionistic and acoustic analysis of accented and unaccented speech are documented. The altered accent displays a slower speech rate and longer duration of consonants and vowels. There is evidence for a shift towards syllable-timed rhythm. NL’s altered accent displays atypical coordination between voicing and supra-laryngeal articulation, reduced mean and range of F0, and minor differences in vowel space. These features are broadly consistent with other documented cases of Foreign Accent Syndrome, regardless of aetiology. However, NL’s profile of preserved and impaired speech does not fit any pattern typically associated with organic neurological disorder. Moreover, left-handed preference may contribute to differences between singing and reading, versus recitation, repetition and spontaneous speech