Relative Age Effect Among the Best Norwegian Track and Field Athletes of All Time: Comparisons of Explosive and Endurance Events

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Comparison of Short-Sprint and Heavy Strength Training on Cycling Performance

Copyright © 2019 Kristoffersen, Sandbakk, Rønnestad and Gundersen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Purpose: To compare the effects of short-sprint training (SST) and heavy-strength training (HST) following a 4-week strength-training period on sprint and endurance capacities in well-trained cyclists. Methods: Twenty-eight competitive cyclists (age 29 ± 6 years) with maximal oxygen uptake (VO˙ 2max) of 61.1 ± 5.9 mL·min−1 ·kg−1 participated. After a 4-weeks preparation strength-training period, the participants were randomized to add either HST or SST to their usual endurance training for the subsequent 6 weeks. Body composition, VO˙ 2max and power output at blood lactate concentration ([La−]) of 4 mmol·L −1 , as well as a 100 min cycling test including 6 and 30-s sprints, 60 min cycling at [La−] of 2 mmol·L −1 and 5-min all-out cycling were performed before the 4-week preparation strengthtraining period, and before and after the 6-week intervention period. In addition, 1 repetition maximum (RM) in half-squat and 55-m maximal sprints on the cyclists’ own bikes were measured before and after the 6-week intervention. Results: SST was superior to HST in 6-s sprint performance, both in a fresh state (4.7 ± 2.6% vs. 1.1 ± 3.5%) and after prolong cycling (6.1 ± 1.8% vs. 1.8 ± 4.2%), in 30-s sprint (3.7 ± 2.8% vs. 1.3 ± 2.5%) and in 55-m seated sprint on own bike (4.3 ± 2.1% vs. 0.2 ± 1.8%) (all p < 0.002). HST induced a larger 1RM improvement in the half-squat test than SST (9.3 ± 3.6% vs. −3.9 ± 3.8%; p < 0.001). No group differences were revealed in the 5-min all-out test, VO˙ 2max, power output at 4 mmol·L −1 [La−], or in gross efficiency. Conclusion: SST led to a greater increase in average and peak power output on all sprint tests compared to HST, whereas HST led to a greater increase in maximal strength. No group differences were found in relative changes in endurance capacities. Altogether, our results show a high degree of specificity in the adaptations of both SST and HST.publishedVersio

The Effects of Alcohol Intoxication on Neuronal Activation at Different Levels of Cognitive Load

The aim of this study was to investigate how alcohol intoxication at two blood alcohol concentrations (BAC) affected neuronal activation during increasing levels of cognitive load. For this purpose we used functional magnetic resonance imaging (fMRI) together with a working memory n-back paradigm with three levels of difficulty. Twenty-five healthy male participants were scanned twice on two separate days. Participants in the control group (N=13) were scanned after drinking a soft-drink at both scanning sessions, while participants in the alcohol group (N=12) were scanned once after drinking an alcoholic beverage resulting in a BAC of 0.02%, and once after drinking an alcoholic beverage resulting in a BAC of 0.08%. A decrease in neuronal activation was seen in the dorsal anterior cingulate cortex (dACC) and in the cerebellum in the alcohol group at the BAC of 0.08% when the participants performed the most demanding task. The dACC is important in cognitive control, working memory, response inhibition, decision making and in error monitoring. The results have revealed that the effect of alcohol intoxication on brain activity is dependent on BAC and of cognitive load

Low cadence interval training at moderate intensity does not improve cycling performance in highly trained veteran cyclists

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The Price Responsiveness of Shale Producers: Evidence from Micro Data

We show that shale oil producers respond positively to favourable oil price signals, and that this response is mainly associated with the timing of production decisions through well completion and refracturing, consistent with the Hotelling theory of optimal extraction. This finding is established using a novel proprietary data set consisting of more than 200,000 shale wells across ten U.S. states spanning almost two decades. We document large heterogeneity in the estimated responses across the various shale wells, suggesting that aggregation bias is an important issue for this kind of analysis. Our empirical results call for new models that can account for a growing share of shale oil in the U.S., the inherent flexibility of shale extraction technology in production and the role of shale oil in transmitting oil price shocks to the global economy.publishedVersio

Soft bottom benthos and responses to climate variation and eutrophication in Skagerrak

Skagerrak has been subject to several anthropogenic influences over the past decades, with climate change and eutrophication being considered as the most serious and large-scale disturbance factors. The present study reports monitoring data from six soft bottom stations in 50–380 m depth at the Norwegian Skagerrak coast aimed at investigating to which degree changes in environmental conditions have affected species communities and diversity. Sampling was carried out yearly in the period 1990–2010. Links between benthic community patterns and climate factors and physicochemical variables from the water mases were examined using uni- and multivariate statistical methods. Throughout the period species richness gradually increased. Although all stations showed distinct species assemblages, the community composition gradually changed towards increased importance of sensitive small molluscs and tube-building annelids concurrent with a general temperature increase and reduction of nutrients in the water masses. The trend was largely similar over the stations, indicating that large-scale changes in the Skagerrak water masses were driving factors compared to possible influences from local sources. The faunal changes during the study period thus indicate an improved status of the soft bottom benthos, which possibly could be related to a reduction in the eutrophication. On a shorter scale, species richness was found to vary in relation to North Atlantic Oscillation (NAO) Index in the previous year (decline), nutrient concentrations in spring (decline), and winter water temperature (incline).acceptedVersio

Changes in pulmonary function and feasibility of portable continuous laryngoscopy during maximal uphill running

Objective To evaluate changes in pulmonary function and feasibility of portable continuous laryngoscopy during maximal uphill running. Methods Healthy volunteers participated in an uphill race. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were obtained before and 5 and 10 min after finishing the race. Capillary blood lactate concentration ([BLa-]) and Borg score for perceived exertion were registered immediately after the race. One participant wore a portable video-laryngoscope during the race, and the video was assessed for technical performance. Results Twenty adult subjects participated with a mean (SD) age of 40.2 (9.7) years. Mean (SD) race duration and post-exercise [BLa-] was 13.9 (2.3) min and 10.7 (2.1) mmol/L, respectively, and the median (range) Borg score for perceived exertion was 9 (5–10). Mean percentage change (95% CI) 5 and 10 min post-exercise in FEV1 were 6.9 (3.7 to 10.2) % and 5.9 (2.7 to 9.0) %, respectively, and in FVC 5.2 (2.3 to 8.1) % and 4.7 (1.6 to 7.9) %, respectively. The recorded video of the larynx was of good quality. Conclusions Maximal aerobic field exercise induced bronchodilatation in the majority of the healthy non-asthmatic participants. It is feasible to perform continuous video-laryngoscopy during heavy uphill exercise.publishedVersio

North Sea Ecosystem Cruise Report_JH2022206

The North Sea Ecosystem cruise (NSEC) is a multi-purpose survey established to monitor distribution and interactions of several components that constitute the lower trophic levels of the pelagic food web including phytoplankton, zooplankton, fish eggs and fish larvae. The cruise is managed by the IMR projects Monitoring of climate and plankton in the North Sea Skagerrak (IMR 14920) and Early life history dynamics of North Sea Fishes (IMR 14917). The cruise provides horizontal and vertical distributions of physical and chemical oceanographic parameters and phytoplankton, zooplankton fish eggs and larvae community composition and structure in the northern North Sea and Skagerrak. Since 2020 the IMR plankton survey was expanded by adding the monitoring of an additional trophic level, microzooplankton. The survey area of the North Sea Ecosystem cruise 2021 covered the northern North Sea and the Skagerrak (57-60.8ºN, 2.2ºW- 8.6ºE). Sampling were made at pre-selected stations along the IMR standard hydrographic transects.North Sea Ecosystem Cruise Report_JH2022206publishedVersio

Sleepiness among personnel in the Norwegian Air Ambulance Service

Purpose. To examine the effects of shift work and extended working hours on sleepiness among pilots and Helicopter Emergency Medical Service (HEMS) crew members in the Norwegian Air Ambulance. Methods. This field study investigated sleepiness during 3 consecutive weeks: the week before work, the work week, and the week after work. The pilots and HEMS crew members (N = 50) kept a wake diary during all 3 weeks and completed reaction time tests during the work week. Results. The overall sleepiness scores were low during all 3 weeks. When comparing the 3 weeks, the lowest sleepiness levels were found for the work week. There was a small difference across work days, in which subjective sleepiness scores were highest the first duty day. No change in the reaction time tests was evident during the work week. The crew members reported being most sleepy at midnight, compared to all the other timepoints over the course of a duty day. Regarding workload and total work time, having larger workload was associated with lower sleepiness scores, while having higher total work time was associated with higher sleepiness score, both compared to the medium category. Conclusions The findings indicate that the work schedules and setting for this distinct occupational group do not seem to negatively affect the sleepiness levels.publishedVersio

Performance in youth track and field is associated with birth quartile. A register-based study among athletes in Norway from 10 years to senior level

Introduction Earlier studies have demonstrated that the oldest in a competition class are more likely to succeed than the youngest, a phenomenon called relative age effect (RAE). Track and field give us an opportunity to investigate the advantage of being born early in the year based upon actual performance, since objective criteria are the performance indicators. Hence, the aim of the present study was to investigate the occurrence of RAE in Norwegian track and field athletes in events where physical capacity is important for success. Methods All individual season best results from the register of The Norwegian Athletics Federation (n = 28 999) obtained in all competition classes from the age of 10 years to senior in both sexes on 60m and 600m from 2011 to 2020 were downloaded. One-way ANOVA and LSD post hoc analyses were used to analyze performance differences according to birth quartiles between athletes. Further, odds ratios (OR) were used to calculate the odds of being among the top-100 for athletes for those born in the first quartile of the year compared to the last. Results The RAE was present in several of the competition classes in sprint compared to middle-distance running, and in more male than female competition classes. Overall, the OR of being among the top-100 in one of the competition classes on 60m sprint when born in first quartile compared to last quartile was 2.88 [2.30–3.62] for males and 1.54 [1.26–1.89] for females. Conclusion Being born early in the year in events with high demand for specific physical capacities is an advantage in both sexes in most of the youngest competition classes. In males, the advantage of being born early in the year lasted longer in sprint than in middle-distance running, indicating that puberty affects performance in sprint and middle-distance running differently.publishedVersio