@uit.no
School of Sports Science
UiT The Arctic University of Norway
Project leader for The Female Endurance Athlete (FENDURA) project and Associate Professor (Exercise Physiology) at the School of Sports Science, UiT The Arctic University of Norway. Researching female-specific aspects, such as the effect of the menstrual cycle and hormonal contraceptives, to improve and optimize the performance and health of female athletes.
2015 - 2019 Doctor of Philosophy (PhD) - Exercise Physiology (Conferred September 2019)
Institute of Health and Biomedical Innovation & School of Exercise and Nutrition Sciences, Queensland University of Technology, Australia
Thesis: Gastrointestinal damage, inflammation and central fatigue during exercise in the heat.
2012 – 2013 Bachelor of Exercise & Nutrition Science – Honours (Class 1)
University of Queensland, Australia
Thesis: Effect of caffeine supplementation on the exercise performance of female cyclists.
2009 – 2012 Bachelor of Exercise & Nutrition Science
University of Queensland, Australia
Public Health, Environmental and Occupational Health, Physical Therapy, Sports Therapy and Rehabilitation, Nutrition and Dietetics, Physiology
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
David N. Borg, Franco M. Impellizzeri, Samantha J. Borg, Kate P. Hutchins, Ian B. Stewart, Tamara Jones, Brenton J. Baguley, Lucas B. R. Orssatto, Aaron J. E. Bach, John O. Osborne,et al.
Wiley
AbstractAimPrediction intervals are a useful measure of uncertainty for meta‐analyses that capture the likely effect size of a new (similar) study based on the included studies. In comparison, confidence intervals reflect the uncertainty around the point estimate but provide an incomplete summary of the underlying heterogeneity in the meta‐analysis. This study aimed to estimate (i) the proportion of meta‐analysis studies that report a prediction interval in sports medicine; and (ii) the proportion of studies with a discrepancy between the reported confidence interval and a calculated prediction interval.MethodsWe screened, at random, 1500 meta‐analysis studies published between 2012 and 2022 in highly ranked sports medicine and medical journals. Articles that used a random effect meta‐analysis model were included in the study. We randomly selected one meta‐analysis from each article to extract data from, which included the number of estimates, the pooled effect, and the confidence and prediction interval.ResultsOf the 1500 articles screened, 866 (514 from sports medicine) used a random effect model. The probability of a prediction interval being reported in sports medicine was 1.7% (95% CI = 0.9%, 3.3%). In medicine the probability was 3.9% (95% CI = 2.4%, 6.6%). A prediction interval was able to be calculated for 220 sports medicine studies. For 60% of these studies, there was a discrepancy in study findings between the reported confidence interval and the calculated prediction interval. Prediction intervals were 3.4 times wider than confidence intervals.ConclusionVery few meta‐analyses report prediction intervals and hence are prone to missing the impact of between‐study heterogeneity on the overall conclusions. The widespread misinterpretation of random effect meta‐analyses could mean that potentially harmful treatments, or those lacking a sufficient evidence base, are being used in practice. Authors, reviewers, and editors should be aware of the importance of prediction intervals.
John O. Osborne, Guro S. Solli, Tina P. Engseth, Boye Welde, Bente Morseth, Dionne A. Noordhof, Øyvind Sandbakk, and Erik P. Andersson
Human Kinetics
Purpose: To describe and compare the annual physical training characteristics between Norwegian female cross-country (XC) skiers and biathletes across competition levels and age categories. Methods: Daily training sessions for 1 year were recorded for 45 XC skiers and 26 biathletes, comprising international/national team (inter[national]) and nonnational/regional team members (nonnational) of both junior and senior age. Endurance, strength, flexibility, speed, and power training sessions were recorded. Data included exercise modality, intensity, and duration. Data were analyzed using linear mixed-effects models. Results: The total annual physical training volume consisted of ∼90% endurance training for both groups, although XC skiers had significantly higher total volumes (∼10%; P = .003; d = 0.78) than biathletes. Senior XC skiers performed more training hours of skiing and/or roller skiing compared with biathletes over the season. However, biathletes compensated for this lower volume by more skating and a higher proportion of endurance training as skiing (81% [17%]) compared with XC skiers (68% [16%]; P < .001; d = 0.94). Overall, (inter)national-level athletes completed a higher annual training volume than non-national-level athletes (740 [90] h vs 649 [95] h; P = .004;d = 0.81). Although juniors reported less endurance volume than seniors, they maintained a relatively stable level of endurance training across the preparatory and competition period, unlike senior athletes. Conclusions: The higher annual physical training volume by XC skiers compared with biathletes is likely caused by the different demands of the 2 sports; XC skiing necessitates training for 2 skiing styles, while biathlon requires additional shooting practice. However, biathletes compensate with a higher proportion of ski training, particularly in the skating technique.
J. O. Osborne, J. Tallent, O. Girard, P. W. Marshall, D. Kidgell, and R. Buhmann
Springer Science and Business Media LLC
Abstract Purpose The use of electrical stimulation to assess voluntary activation of muscle/s is a popular method employed in numerous exercise science and health research settings. This Delphi study aimed to collate expert opinion and provide recommendations for best practice when using electrical stimulation during maximal voluntary contractions. Methods A two-round Delphi study was undertaken with 30 experts who completed a 62-item questionnaire (Round 1) comprising of open- and closed-ended questions. Consensus was assumed if ≥ 70% of experts selected the same response; such questions were removed from the subsequent Round 2 questionnaire. Responses were also removed if they failed to meet a 15% threshold. Open-ended questions were analysed and converted into closed-ended questions for Round 2. It was assumed there was no clear consensus if a question failed to achieve a ≥ 70% response in Round 2. Results A total of 16 out of 62 (25.8%) items reached consensus. Experts agreed that electrical stimulation provides a valid assessment of voluntary activation in specific circumstances, such as during maximal contraction, and this stimulation can be applied at either the muscle or the nerve. Experts recommended using doublet stimuli, self-adhesive electrodes, a familiarisation session, real-time visual or verbal feedback during the contraction, a minimum current increase of + 20% to ensure supramaximal stimulation, and manually triggering stimuli. Conclusion The results of this Delphi consensus study can help researchers make informed decisions when considering technical parameters when designing studies involving electrical stimulation for the assessment of voluntary activation.
Hanne C. Staff, Guro Strøm Solli, John O. Osborne, and Øyvind Sandbakk
Springer Science and Business Media LLC
Abstract Objective In this scoping review, we aimed to 1) identify and evaluate existing research that describes the long-term development of training characteristics and performance-determining factors in male and female endurance athletes reaching an elite/international (Tier 4) or world-class level (Tier 5), 2) summarize the available evidence and 3) point out existing knowledge gaps and provide methodological guidelines for future research in this field. Methods This review was conducted following the Joanna Briggs Institute methodology for scoping reviews. Results Out of 16772 screened items across a 22-year period (1990-2022), a total of 17 peer-reviewed journal articles met the inclusion criteria and were considered for further analysis. These 17 studies described athletes from seven different sports and seven different countries, with 11 (69%) of the studies being published during the last decade. Of the 109 athletes included in this scoping review, one quarter were women (27%), and three quarters were men (73%). Ten studies included information about the long-term development of training volume and training intensity distribution. A non-linear, year-to-year increase in training volume was found for most athletes, resulting in a subsequent plateau. Furthermore, 11 studies described the development of performance determining factors. Here, most of the studies showed improvements in submaximal variables (e.g., lactate/anaerobic threshold and work economy/efficiency) and maximal performance-indices (e.g., peak speed/watt during performance testing). Conversely, the development of VO2max was inconsistent across studies. No evidence was found regarding possible sex differences in development of training or performance-determining factors among endurance athletes. Conclusion Overall, a low number of studies describing the long-term development of training and performance-determining factors is available. This suggests that existing talent development practices in endurance sports are built upon limited scientific evidence. Overall, there is an urgent need for additional long-term studies based on systematic monitoring of athletes from a young age utilizing high-precision, reproducible measurements of training and performance-determining factors.
Erik P. Andersson, Thomas L. Stöggl, Philipp Bachl, and John O. Osborne
American Physiological Society
This study demonstrates that GE declines during a 3-min supramaximal cycle TT, which is possibly related to the hyperpneic response during supramaximal exercise. The finding from this study also provides novel insight into how the increased ventilatory energy cost from exercise-induced hyperpnea contributes to decreased GE, increased required total metabolic rate, and increased anaerobic energy expenditure during supramaximal exercise. Therefore, conventional linear models for estimating anaerobic capacity are likely to generate underestimated values.
John O. Osborne, Geoffrey M. Minett, Ian B. Stewart, Stewart Trost, Christopher Drovandi, Joseph T. Costello, Toby G. Pavey, and David N. Borg
Informa UK Limited
This randomized cross-over study tested the hypothesis that heat acclimation training would detrimentally affect sleep variables and alter incidental physical activity compared to a thermoneutral training control condition. Eight recreationally trained males (VO2peak 49±4.9 mL.kg-1.min-1) completed two separate interventions separated by at least 31 days: 5 consecutive day training blocks of moderate-intensity cycling (60 min·day-1 at 50% peak power output) in a hot (34.9±0.7 °C and 53±4 % relative humidity) and a temperate (22.2±2.6 °C; 65±8 % relative humidity) environment. Wrist-mounted accelerometers were worn continuously for the length of the training blocks and recorded physical activity, sleep quality and quantity. Data were analysed in a Bayesian framework, with the results presented as the posterior probability that a coefficient was greater or less than zero. Compared to the temperate training environment, heat acclimation impaired sleep efficiency (Pr β<0 = .979) and wake on sleep onset (Pr β>0 = .917). Daily sedentary time was, on average, 35 min longer (Pr β>0 = .973) and light physical activity time 18 min shorter (Pr β>0 = .960) during the heat acclimation period. No differences were observed between conditions in sleep duration, subjective sleep quality, or moderate or vigorous physical activity. These findings may suggest that athletes and coaches need to be cognisant that heat acclimation training may alter sleep quality and increase sedentary behaviour.Highlights Five consecutive days of heat training negatively affected some objective measures of sleep quality and incidental physical activity in recreationally trained athletes.Athletes and coaches need to be aware of the potential unintended consequences of using heat acclimation on sleep behaviours.
David N. Borg, John O. Osborne, Sean M. Tweedy, Johanna B. Liljedahl, and Carla F. J. Nooijen
Ovid Technologies (Wolters Kluwer Health)
Abstract This study described bicycling (C classes) and tricycling (T classes) performance in the International Cycling Federation road race events between 2011 and 2019. A total of 3243 race results from 33 events were analyzed. Race velocity was calculated for each result. Bicycling and tricycling data were separately modeled using a linear mixed-effects model. Bicycling velocity was statistically different between all adjacent men’s classes (Cohen d = 0.14–0.73) and between the women’s C1 and C2 (d = 1.15) and C3 and C4 (d = 0.48) classes. The absence of statistical differences between some women’s bicycling classes may be due to a limited number of observations in these classifications. As expected, velocity was statistically different between men’s (d = 1.64) and women’s (d = 1.38) T1 and T2 classes. Road race performance was hierarchical within the disciplines of bicycling and tricycling, although not all adjacent women’s bicycling classes were statistically different. The existence of a performance hierarchy does not necessarily validate the classification system. The integration of information regarding athlete impairment type and severity, with performance data, would provide greater insight into the validity of the classification system and should be prioritized as an area of future research.
John O. Osborne, Ian B. Stewart, David N. Borg, Kenneth W. Beagley, Robert L. Buhmann, and Geoffrey M. Minett
Springer Science and Business Media LLC
Abstract Purpose This study investigated the effect of 5 days of heat acclimation training on neuromuscular function, intestinal damage, and 20 km cycling (20TT) performance in the heat. Methods Eight recreationally trained males completed two 5-day training blocks (cycling 60 min day−1 at 50% peak power output) in a counter-balanced, cross-over design, with a 20TT completed before and after each block. Training was conducted in hot (HA: 34.9 ± 0.7 °C, 53 ± 4% relative humidity) or temperate (CON: 22.2 ± 2.6 °C, 65 ± 8% relative humidity) environment. All 20TTs were completed in the heat (35.1 ± 0.5 °C, 51 ± 4% relative humidity). Neuromuscular assessment of knee extensors (5 × 5 s maximum voluntary contraction; MVC) was completed before and after each 20TT and on the first and last days of each training block. Results MVC torque was statistically higher after 5 days of HA training compared to CON (mean difference = 14 N m [95% confidence interval; 6, 23]; p < 0.001; d = 0.77). However, 20TT performance after 5 days of HA training was not statistically different to CON, with a between-conditions mean difference in the completion time of 68 s [95% confidence interval; − 9, 145] (p = 0.076; d = 0.35). Conclusion Short-term heat acclimation training may increase knee extensor strength without changes in central fatigue or intestinal damage. Nevertheless, it is insufficient to improve 20 km self-paced cycling performance in the heat compared to workload-matched training in a temperate environment. These data suggest that recreationally trained athletes gain no worthwhile performance advantage from short-term heat-training before competing in the heat.
David N. Borg, John O. Osborne, Ian B. Stewart, Joseph T. Costello, Jonathon Headrick, Benjamin S. McMaster, Samantha J. Borg, and Geoffrey M. Minett
Elsevier BV
David N. Borg, Ian B. Stewart, John O. Osborne, Christopher Drovandi, Joseph T. Costello, Jamie Stanley, and Geoffrey M. Minett
Human Kinetics
Purpose: To examine the effects of daily cold- and hot-water recovery on training load (TL) during 5 days of heat-based training. Methods: Eight men completed 5 days of cycle training for 60 minutes (50% peak power output) in 4 different conditions in a block counter-balanced-order design. Three conditions were completed in the heat (35°C) and 1 in a thermoneutral environment (24°C; CON). Each day after cycling, participants completed 20 minutes of seated rest (CON and heat training [HT]) or cold- (14°C; HTCWI) or hot-water (39°C; HTHWI) immersion. Heart rate, rectal temperature, and rating of perceived exertion (RPE) were collected during cycling. Session-RPE was collected 10 minutes after recovery for the determination of session-RPE TL. Data were analyzed using hierarchical regression in a Bayesian framework; Cohen d was calculated, and for session-RPE TL, the probability that d > 0.5 was also computed. Results: There was evidence that session-RPE TL was increased in HTCWI (d = 2.90) and HTHWI (d = 2.38) compared with HT. The probabilities that d > 0.5 were .99 and .96, respectively. The higher session-RPE TL observed in HTCWI coincided with a greater cardiovascular (d = 2.29) and thermoregulatory (d = 2.68) response during cycling than in HT. This result was not observed for HTHWI. Conclusion: These findings suggest that cold-water recovery may negatively affect TL during 5 days of heat-based training, hot-water recovery could increase session-RPE TL, and the session-RPE method can detect environmental temperature-mediated increases in TL in the context of this study.
John O. Osborne, Ian B. Stewart, Kenneth W. Beagley, David N. Borg, and Geoffrey M. Minett
Springer Science and Business Media LLC
John O. Osborne, Ian B. Stewart, Kenneth W. Beagley, and Geoffrey M. Minett
Springer Science and Business Media LLC
TINA L. SKINNER, BEN DESBROW, JULIA ARAPOVA, MIA A. SCHAUMBERG, JOHN OSBORNE, GARY D. GRANT, SHAILENDRA ANOOPKUMAR-DUKIE, and MICHAEL D. LEVERITT
Ovid Technologies (Wolters Kluwer Health)
Purpose This study aimed to determine whether 1) consumption of caffeine improves endurance cycling performance in women and 2) sex differences exist in the magnitude of the ergogenic and plasma responses to caffeine supplementation. Methods Twenty-seven (11 women and 16 men) endurance-trained cyclists and triathletes participated in this randomized, double-blind, placebo-controlled, crossover study. Participants completed an incremental exercise test to exhaustion, two familiarization trials, and two performance trials. Ninety minutes before the performance trials, participants ingested opaque capsules containing either 3 mg·kg−1 body mass of anhydrous caffeine or a placebo. They then completed a set amount of work (75% of peak sustainable power output) in the fastest possible time. Plasma was sampled at baseline, preexercise, and postexercise for caffeine. Strict standardization and verification of diet, hydration, training volume and intensity, and contraceptive hormone phase (for women) were implemented. Results Performance time was significantly improved after caffeine administration in women (placebo: 3863 ± 419 s, caffeine: 3757 ± 312 s; P = 0.03) and men (placebo: 3903 ± 341 s, caffeine: 3734 ± 287 s; P < 0.001). The magnitude of performance improvement was similar for women (mean = 4.3%, 95% CI = 0.4%–8.2%) and men (4.6%, 2.3%–6.8%). Plasma caffeine concentrations were similar between sexes before exercise, but significantly greater in women after exercise (P < 0.001). Conclusions Ingestion of 3 mg·kg−1 body mass of caffeine enhanced endurance exercise performance in women. The magnitude of the performance enhancement observed in women was similar to that of men, despite significantly greater plasma caffeine concentrations after exercise in women. These results suggest that the current recommendations for caffeine intake (i.e., 3–6 mg·kg−1 caffeine before exercise to enhance endurance performance), which are derived almost exclusively from studies on men, may also be applicable to women.
David N. Borg, John O. Osborne, Ian B. Stewart, Joseph T. Costello, Jesse N.L. Sims, and Geoffrey M. Minett
Elsevier BV