21 research outputs found
Acute and Delayed Effects of Time-Matched Very Short âAll Outâ Efforts in Concentric vs. Eccentric Cycling
[EN] Abstract: Background: To the authorsâ knowledge, there have been no studies comparing the acute
responses to âall outâ efforts in concentric (isoinertial) vs. eccentric (isovelocity) cycling. Methods:
After two familiarization sessions, 12 physically active men underwent the experimental protocols
consisting of a 2-min warm-up and 8 maximal efforts of 5 s, separated by 55 s of active recovery
at 80 rpm , in concentric vs. eccentric cycling. Comparisons between protocols were conducted
during, immediately after, and 24-h post-sessions. Results: Mechanical (Work: 82,824 ± 6350 vs.
60,602 ± 8904 J) and cardiometabolic responses (mean HR: 68.8 ± 6.6 vs. 51.3 ± 5.7% HRmax, lac-
tate: 4.9 ± 2.1 vs. 1.8 ± 0.6 mmol/L) were larger in concentric cycling (p < 0.001). The perceptual
responses to both protocols were similarly low. Immediately after concentric cycling, vertical jump
was potentiated (p = 0.028). Muscle soreness (VAS; p = 0.016) and thigh circumference (p = 0.045)
were slightly increased only 24-h after eccentric cycling. Serum concentrations of CK, BAG3, and
MMP-13 did not change significantly post-exercise. Conclusions: These results suggest the appro-
priateness of the eccentric cycling protocol used as a time-efficient (i.e., ~60 kJ in 10 min) and safe
(i.e., without exercise-induced muscle damage) alternative to be used with different populations in
future longitudinal interventions
Restricted nasal-only breathing during self-selected low intensity training does not affect training intensity distribution
Introduction: Low-intensity endurance training is frequently performed at gradually higher training intensities than intended, resulting in a shift towards threshold training. By restricting oral breathing and only allowing for nasal breathing this shift might be reduced.Methods: Nineteen physically healthy adults (3 females, age: 26.5 ± 5.1 years; height: 1.77 ± 0.08 m; body mass: 77.3 ± 11.4 kg; VO2peak: 53.4 ± 6.6 mL·kgâ1 minâ1) performed 60 min of self-selected, similar (144.7 ± 56.3 vs. 147.0 ± 54.2 W, p = 0.60) low-intensity cycling with breathing restriction (nasal-only breathing) and without restrictions (oro-nasal breathing). During these sessions heart rate, respiratory gas exchange data and power output data were recorded continuously.Results: Total ventilation (p < 0.001, ηp2 = 0.45), carbon dioxide release (p = 0.02, ηp2 = 0.28), oxygen uptake (p = 0.03, ηp2 = 0.23), and breathing frequency (p = 0.01, ηp2 = 0.35) were lower during nasal-only breathing. Furthermore, lower capillary blood lactate concentrations were found towards the end of the training session during nasal-only breathing (time x condition-interaction effect: p = 0.02, ηp2 = 0.17). Even though discomfort was rated marginally higher during nasal-only breathing (p = 0.03, ηp2 = 0.24), ratings of perceived effort did not differ between the two conditions (p â„ 0.06, ηp2 = 0.01). No significant âconditionâ differences were found for intensity distribution (time spent in training zone quantified by power output and heart rate) (p â„ 0.24, ηp2 †0.07).Conclusion: Nasal-only breathing seems to be associated with possible physiological changes that may help to maintain physical health in endurance athletes during low intensity endurance training. However, it did not prevent participants from performing low-intensity training at higher intensities than intended. Longitudinal studies are warranted to evaluate longitudinal responses of changes in breathing patterns
Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans
Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have
fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in
25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16
regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of
correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP,
while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in
Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium
(LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region.
Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant
enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the
refined data for existing association signals, we estimate that these loci now explain âŒ38.9% of the familial relative risk of PrCa,
an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of
PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent
signals within the same regio
Valid and Reliable Barbell Velocity Estimation Using an Inertial Measurement Unit
The accurate assessment of the mean concentric barbell velocity (MCV) and its displacement are crucial aspects of resistance training. Therefore, the validity and reliability indicators of an easy-to-use inertial measurement unit (VmaxProÂź) were examined. Nineteen trained males (23.1 ± 3.2 years, 1.78 ± 0.08 m, 75.8 ± 9.8 kg; Squat 1-Repetition maximum (1RM): 114.8 ± 24.5 kg) performed squats and hip thrusts (3â5 sets, 30 repetitions total, 75% 1RM) on two separate days. The MCV and displacement were simultaneously measured using VmaxProÂź and a linear position transducer (Speed4LiftÂź). Good to excellent intraclass correlation coefficients (0.91 < ICC < 0.96) with a small systematic bias (p < 0.001; ηp2 < 0.50) for squats (0.01 ± 0.04 m·sâ1) and hip thrusts (0.01 ± 0.05 m·sâ1) and a low limit of agreement (LoA < 0.12 m·sâ1) indicated an acceptable validity. The within- and between-day reliability of the MCV revealed good ICCs (0.55 < ICC < 0.91) and a low LoA (<0.16 m·sâ1). Although the displacement revealed a systematic bias during squats (p < 0.001; ηp2 < 0.10; 3.4 ± 3.4 cm), no bias was detectable during hip thrusts (p = 0.784; ηp2 < 0.001; 0.3 ± 3.3 cm). The displacement showed moderate to good ICCs (0.43 to 0.95) but a high LoA (7.8 to 10.7 cm) for the validity and (within- and between-day) reliability of squats and hip thrusts. The VmaxProÂź is considered to be a valid and reliable tool for the MCV assessment
Acute and Delayed Effects of Time-Matched Very Short âAll Outâ Efforts in Concentric vs. Eccentric Cycling
Background: To the authorsâ knowledge, there have been no studies comparing the acute responses to âall outâ efforts in concentric (isoinertial) vs. eccentric (isovelocity) cycling. Methods: After two familiarization sessions, 12 physically active men underwent the experimental protocols consisting of a 2-min warm-up and 8 maximal efforts of 5 s, separated by 55 s of active recovery at 80 rpm, in concentric vs. eccentric cycling. Comparisons between protocols were conducted during, immediately after, and 24-h post-sessions. Results: Mechanical (Work: 82,824 ± 6350 vs. 60,602 ± 8904 J) and cardiometabolic responses (mean HR: 68.8 ± 6.6 vs. 51.3 ± 5.7% HRmax, lactate: 4.9 ± 2.1 vs. 1.8 ± 0.6 mmol/L) were larger in concentric cycling (p < 0.001). The perceptual responses to both protocols were similarly low. Immediately after concentric cycling, vertical jump was potentiated (p = 0.028). Muscle soreness (VAS; p = 0.016) and thigh circumference (p = 0.045) were slightly increased only 24-h after eccentric cycling. Serum concentrations of CK, BAG3, and MMP-13 did not change significantly post-exercise. Conclusions: These results suggest the appropriateness of the eccentric cycling protocol used as a time-efficient (i.e., ~60 kJ in 10 min) and safe (i.e., without exercise-induced muscle damage) alternative to be used with different populations in future longitudinal interventions
Presentation1_Restricted nasal-only breathing during self-selected low intensity training does not affect training intensity distribution.pdf
Introduction: Low-intensity endurance training is frequently performed at gradually higher training intensities than intended, resulting in a shift towards threshold training. By restricting oral breathing and only allowing for nasal breathing this shift might be reduced.Methods: Nineteen physically healthy adults (3 females, age: 26.5 ± 5.1 years; height: 1.77 ± 0.08 m; body mass: 77.3 ± 11.4 kg; VO2peak: 53.4 ± 6.6 mL·kgâ1 minâ1) performed 60 min of self-selected, similar (144.7 ± 56.3 vs. 147.0 ± 54.2 W, p = 0.60) low-intensity cycling with breathing restriction (nasal-only breathing) and without restrictions (oro-nasal breathing). During these sessions heart rate, respiratory gas exchange data and power output data were recorded continuously.Results: Total ventilation (p p2 = 0.45), carbon dioxide release (p = 0.02, ηp2 = 0.28), oxygen uptake (p = 0.03, ηp2 = 0.23), and breathing frequency (p = 0.01, ηp2 = 0.35) were lower during nasal-only breathing. Furthermore, lower capillary blood lactate concentrations were found towards the end of the training session during nasal-only breathing (time x condition-interaction effect: p = 0.02, ηp2 = 0.17). Even though discomfort was rated marginally higher during nasal-only breathing (p = 0.03, ηp2 = 0.24), ratings of perceived effort did not differ between the two conditions (p â„ 0.06, ηp2 = 0.01). No significant âconditionâ differences were found for intensity distribution (time spent in training zone quantified by power output and heart rate) (p â„ 0.24, ηp2 †0.07).Conclusion: Nasal-only breathing seems to be associated with possible physiological changes that may help to maintain physical health in endurance athletes during low intensity endurance training. However, it did not prevent participants from performing low-intensity training at higher intensities than intended. Longitudinal studies are warranted to evaluate longitudinal responses of changes in breathing patterns.</p
Presentation2_Restricted nasal-only breathing during self-selected low intensity training does not affect training intensity distribution.pdf
Introduction: Low-intensity endurance training is frequently performed at gradually higher training intensities than intended, resulting in a shift towards threshold training. By restricting oral breathing and only allowing for nasal breathing this shift might be reduced.Methods: Nineteen physically healthy adults (3 females, age: 26.5 ± 5.1 years; height: 1.77 ± 0.08 m; body mass: 77.3 ± 11.4 kg; VO2peak: 53.4 ± 6.6 mL·kgâ1 minâ1) performed 60 min of self-selected, similar (144.7 ± 56.3 vs. 147.0 ± 54.2 W, p = 0.60) low-intensity cycling with breathing restriction (nasal-only breathing) and without restrictions (oro-nasal breathing). During these sessions heart rate, respiratory gas exchange data and power output data were recorded continuously.Results: Total ventilation (p p2 = 0.45), carbon dioxide release (p = 0.02, ηp2 = 0.28), oxygen uptake (p = 0.03, ηp2 = 0.23), and breathing frequency (p = 0.01, ηp2 = 0.35) were lower during nasal-only breathing. Furthermore, lower capillary blood lactate concentrations were found towards the end of the training session during nasal-only breathing (time x condition-interaction effect: p = 0.02, ηp2 = 0.17). Even though discomfort was rated marginally higher during nasal-only breathing (p = 0.03, ηp2 = 0.24), ratings of perceived effort did not differ between the two conditions (p â„ 0.06, ηp2 = 0.01). No significant âconditionâ differences were found for intensity distribution (time spent in training zone quantified by power output and heart rate) (p â„ 0.24, ηp2 †0.07).Conclusion: Nasal-only breathing seems to be associated with possible physiological changes that may help to maintain physical health in endurance athletes during low intensity endurance training. However, it did not prevent participants from performing low-intensity training at higher intensities than intended. Longitudinal studies are warranted to evaluate longitudinal responses of changes in breathing patterns.</p
Quantitative Measures of Craniofacial Dysmorphology in a Family Study of Schizophrenia and Bipolar Illness
Several laboratories, including ours, have reported an overrepresentation of craniofacial (CF) anomalies in schizophrenia (SZ). How might this dysmorphology arise in a brain-based disorder? Because the brain and face derive from shared embryologic primordia and morphogenetic forces, maldevelopmental processes may result in both CF and brain dysmorphology. Our approach is 2-pronged. First, we have employed, for the first time in the study of psychiatric disorders, objective measures of CF morphology that utilize an extensive normative database, permitting computation of standardized scores for each subject. Second, we have rendered these findings biologically interpretable by adopting principles of embryology in the analysis of dysmorphology. Dependent measures in this investigation focused on derivatives of specific embryonic primordia and were contrasted among probands with psychotic disorders, their first-degree relatives, and normal controls (NC). Subject groups included patients with a diagnosis of SZ (N = 39) or bipolar (BP) disorder with psychotic features (N = 32), their clinically unaffected relatives (N = 82 and N = 41, respectively), and NC (N = 95) subjects. Anomalies involving derivatives of frontonasal and mandibular embryonic primordia showed a clear association with psychotic illness, as well as familial aggregation in relatives in both diagnostic groups. In contrast, one class of CF anomalies emerged only among SZ probands and their first-degree relatives: dysmorphology arising along the junction of the frontonasal and maxillary prominence derivatives, manifested as marked asymmetries. This class was not overrepresented among the BP patients nor among their relatives, indicating that this dysmorphology appears to be specific to SZ and not a generalized feature of psychosis. We discuss these findings in light of embryologic models that relate brain regions to specific CF areas