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Dive into the research topics where Dionne A. Noordhof is active.

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Featured researches published by Dionne A. Noordhof.


Sports Medicine | 2010

The maximal accumulated oxygen deficit method: a valid and reliable measure of anaerobic capacity?

Dionne A. Noordhof; Jos J. de Koning; Carl Foster

The maximal accumulated oxygen deficit (MAOD) method has been extensively, but unfortunately not very methodically, used; the procedure used to determine the MAOD varies considerably. Therefore, this review evaluates the effect of different numbers and durations of submaximal exercise bouts on the linear power output (PO)-oxygen uptake (V̇O2) relationship and thus the MAOD. Changing the number and duration of the submaximal exercise bouts substantially influences the calculated MAOD when relatively long submaximal exercise bouts are used and no fixed value of the y-intercept is forced into the linear regression line. This is most likely due to non-linearity of the PO-V̇O2 relationship for exercise intensities above the lactate threshold (LT). Non-linearity of the PO-V̇O2 relationship is probably caused by the development of a slow component in V̇O2 during submaximal exercise at intensities above the LT. Thus, it is important to standardize the number, duration and intensity of submaximal exercise bouts necessary to establish the PO-V̇O2 relationship. Beyond changing the number and duration of the submaximal exercise bouts, the effect of different supramaximal exercise bouts on the calculated MAOD has been investigated. While it has become clear that different exercise protocols result in relatively similar values of the MAOD, a closer look at individual data suggests that it may be important to choose an exercise protocol that is representative of the athlete’s event. The validity of the MAOD method was studied by different authors comparing the MAOD with metabolic measurements of anaerobic adenosine triphosphate (ATP) production. The main limitation with the metabolic measurements of anaerobic ATP production from muscle biopsy data is that the active muscle mass is unknown, which makes it hard to accurately study the validity of the MAOD method. From the studies that evaluated the reliability of the MAOD method it is clear that the MAOD method may not be a reliable measure of anaerobic capacity. From these findings it can be concluded that the MAOD method may have limitations as a valid and reliable measure of anaerobic capacity and needs to be further improved. We suggest the use of 10 x 4 minute submaximal exercise bouts and a fixed value of the y-intercept for the construction of the linear PO-V̇O2 relationship, after which the MAOD can be determined during a supramaximal exercise protocol specific for the athlete’s event. This method will lead to a more robust PO-V̇O2 relationship and will therefore result in more valid and reliable results.


International Journal of Sports Medicine | 2012

Factors Affecting Gross Efficiency in Cycling

J.J. de Koning; Dionne A. Noordhof; Alejandro Lucia; Carl Foster

There is little standardization of how to measure cycling gross efficiency (GE). Therefore, the purposes of these studies were to evaluate the effect of: i) stage duration, ii) relative exercise intensity, iii) work capacity and iv) a prior maximal incremental test on GE. Trained subjects (n=28) performed incremental tests with stage durations of 1-, 3-, and 6-min to establish the effect of stage duration and relative exercise intensity on GE. The effect of work capacity was evaluated by correlating GE with peak power output (PPO). In different subjects (n=9), GE was measured at 50% PPO with and without a prior maximal incremental test. GE was similar in 3- and 6-min stages (19.7 ± 2.8% and 19.3 ± 2.0%), but significantly higher during 1-min stages (21.1 ± 2.7%), GE increased with relative exercise intensity, up to 50% PPO or the power output corresponding to the ventilatory threshold and then remained stable. No relationship between work capacity and GE was found. Prior maximal exercise had a small effect on GE measures; GE was lower after maximal exercise. In conclusion, GE can be determined robustly so long as steady state exercise is performed and RER ≤ 1.0.


Journal of Applied Physiology | 2016

Maximal oxygen uptake is proportional to muscle fiber oxidative capacity, from chronic heart failure patients to professional cyclists

Stephan van der Zwaard; Jo C. de Ruiter; Dionne A. Noordhof; Renske Sterrenburg; Frank W. Bloemers; Jos J. de Koning; Richard T. Jaspers; Willem J. van der Laarse

V̇o2 max during whole body exercise is presumably constrained by oxygen delivery to mitochondria rather than by mitochondrias ability to consume oxygen. Humans and animals have been reported to exploit only 60-80% of their mitochondrial oxidative capacity at maximal oxygen uptake (V̇o2 max). However, ex vivo quantification of mitochondrial overcapacity is complicated by isolation or permeabilization procedures. An alternative method for estimating mitochondrial oxidative capacity is via enzyme histochemical quantification of succinate dehydrogenase (SDH) activity. We determined to what extent V̇o2 max attained during cycling exercise differs from mitochondrial oxidative capacity predicted from SDH activity of vastus lateralis muscle in chronic heart failure patients, healthy controls, and cyclists. V̇o2 max was assessed in 20 healthy subjects and 28 cyclists, and SDH activity was determined from biopsy cryosections of vastus lateralis using quantitative histochemistry. Similar data from our laboratory of 14 chronic heart failure patients and 6 controls were included. Mitochondrial oxidative capacity was predicted from SDH activity using estimated skeletal muscle mass and the relationship between ex vivo fiber V̇o2 max and SDH activity of isolated single muscle fibers and myocardial trabecula under hyperoxic conditions. Mitochondrial oxidative capacity predicted from SDH activity was related (r(2) = 0.89, P < 0.001) to V̇o2 max measured during cycling in subjects with V̇o2 max ranging from 9.8 to 79.0 ml·kg(-1)·min(-1) V̇o2 max measured during cycling was on average 90 ± 14% of mitochondrial oxidative capacity. We conclude that human V̇o2 max is related to mitochondrial oxidative capacity predicted from skeletal muscle SDH activity. Mitochondrial oxidative capacity is likely marginally limited by oxygen supply to mitochondria.


International Journal of Sports Medicine | 2011

Anaerobic Capacity: Effect of Computational Method

Dionne A. Noordhof; Ankie Vink; J.J. de Koning; Carl Foster

Anaerobic capacity (AnC) can be estimated by subtracting VO (2) consumed from VO (2) demand, which can be estimated from multiple submaximal exercise bouts or by gross efficiency (GE), requiring one submaximal bout. This study compares AnC using the MAOD and GE method. The precision of estimated VO (2) demand and AnC, determined by MAOD using 3 power output - VO (2) regressions, based on VO (2) from min 8-10 (10 - Y), during min 4 without (4 - Y) and with forced y-intercept (4+Y), and from GE was evaluated by the 95% confidence interval (CI). Well-trained males (n=15) performed submaximal exercise tests to establish VO (2) demand with the MAOD and GE method. To determine AnC subjects completed a constant power output trial. The 3 MAOD procedures and GE method had no significant difference for VO (2) demand and AnC. The 4+Y MAOD procedure and GE method resulted in a smaller 95% CI of VO (2) demand and AnC than the 10 - Y ( P<0.05; P<0.01) and 4 - Y ( P<0.001; P<0.01) MAOD procedures. Therefore, the 4+Y MAOD procedure and GE method are preferred for estimating AnC, but as individual differences exist, they cannot be used interchangeably.


PLOS ONE | 2016

Oxygenation Threshold Derived from Near-Infrared Spectroscopy: Reliability and Its Relationship with the First Ventilatory Threshold

Stephan van der Zwaard; Richard T. Jaspers; Ilse J. Blokland; Chantal Achterberg; Jurrian M. Visser; Anne R. den Uil; Mathijs J. Hofmijster; K. Levels; Dionne A. Noordhof; Arnold de Haan; Jos J. de Koning; Willem J. van der Laarse; Cornelis J. de Ruiter

Background Near-infrared spectroscopy (NIRS) measurements of oxygenation reflect O2 delivery and utilization in exercising muscle and may improve detection of a critical exercise threshold. Purpose First, to detect an oxygenation breakpoint (Δ[O2HbMb-HHbMb]-BP) and compare this breakpoint to ventilatory thresholds during a maximal incremental test across sexes and training status. Second, to assess reproducibility of NIRS signals and exercise thresholds and investigate confounding effects of adipose tissue thickness on NIRS measurements. Methods Forty subjects (10 trained male cyclists, 10 trained female cyclists, 11 endurance trained males and 9 recreationally trained males) performed maximal incremental cycling exercise to determine Δ[O2HbMb-HHbMb]-BP and ventilatory thresholds (VT1 and VT2). Muscle haemoglobin and myoglobin O2 oxygenation ([HHbMb], [O2HbMb], SmO2) was determined in m. vastus lateralis. Δ[O2HbMb-HHbMb]-BP was determined by double linear regression. Trained cyclists performed the maximal incremental test twice to assess reproducibility. Adipose tissue thickness (ATT) was determined by skinfold measurements. Results Δ[O2HbMb-HHbMb]-BP was not different from VT1, but only moderately related (r = 0.58–0.63, p<0.001). VT1 was different across sexes and training status, whereas Δ[O2HbMb-HHbMb]-BP differed only across sexes. Reproducibility was high for SmO2 (ICC = 0.69–0.97), Δ[O2HbMb-HHbMb]-BP (ICC = 0.80–0.88) and ventilatory thresholds (ICC = 0.96–0.99). SmO2 at peak exercise and at occlusion were strongly related to adipose tissue thickness (r2 = 0.81, p<0.001; r2 = 0.79, p<0.001). Moreover, ATT was related to asymmetric changes in Δ[HHbMb] and Δ[O2HbMb] during incremental exercise (r = -0.64, p<0.001) and during occlusion (r = -0.50, p<0.05). Conclusion Although the oxygenation threshold is reproducible and potentially a suitable exercise threshold, VT1 discriminates better across sexes and training status during maximal stepwise incremental exercise. Continuous-wave NIRS measurements are reproducible, but strongly affected by adipose tissue thickness.


International Journal of Sports Physiology and Performance | 2014

The Association Between Changes in Speed Skating Technique and Changes in Skating Velocity

Dionne A. Noordhof; Carl Foster; M.J.M. Hoozemans; Jos J. de Koning

UNLABELLED A meaningful association between changes (Δ) in push-off angle or effectiveness (e) and changes in skating velocity (v) has been found during 5000-m races, although no significant association was found between changes in knee (θ0) and trunk angle (θ1) and Δv. It might be that speed skating event, sex, and performance level influence these associations. PURPOSE To study the effect of skating event, sex, and performance level on the association between Δe and Δv and between Δθ0 and Δθ1 and Δv. METHODS Video recordings were made from frontal (e) and sagittal views (θ0 and θ1) during 1500- and 5000-m mens and womens World Cup races. Radio-frequency identification tags provided data of v. RESULTS Skating event influenced the association between Δe and Δv, which resulted in a significant association between Δe and Δv for the 5000-m (β = -0.069, 95% confidence interval [-0.11, -0.030]) but not for the 1500-m (β = -0.011 [-0.032, 0.010]). The association between Δθ0 and Δθ1 and Δv was not significantly influenced by skating event. Sex and performance level did not substantially affect the association between Δe and Δv and between Δθ0 and Δθ1 and Δv. CONCLUSIONS Skating event significantly influenced the association between Δe and Δv; a 1° change in e results in a 0.011-m/s decrease in v during the 1500-m and a 0.069-m/s decrease in v during the 5000-m. Thus, it seems especially important to maintain a small e during the 5000-m.


International Journal of Sports Physiology and Performance | 2016

Race Factors Affecting Performance Times in Elite Long-Track Speed Skating

Dionne A. Noordhof; Roy C.M. Mulder; Jos J. de Koning; Will G. Hopkins

UNLABELLED Analysis of sport performance can provide effects of environmental and other venue-specific factors in addition to estimates of within-athlete variability between competitions, which determines smallest worthwhile effects. PURPOSE To analyze elite long-track speed-skating events. METHODS Log-transformed performance times were analyzed with a mixed linear model that estimated percentage mean effects for altitude, barometric pressure, type of rink, and competition importance. In addition, coefficients of variation representing residual venue-related differences and within-athlete variability between races within clusters spanning ~8 d were determined. Effects and variability were assessed with magnitude-based inference. RESULTS A 1000-m increase in altitude resulted in very large mean performance improvements of 2.8% in juniors and 2.1% in seniors. An increase in barometric pressure of 100 hPa resulted in a moderate reduction in performance of 1.1% for juniors but an unclear effect for seniors. Only juniors competed at open rinks, resulting in a very large reduction in performance of 3.4%. Juniors and seniors showed small performance improvements (0.4% and 0.3%) at the more important competitions. After accounting for these effects, residual venue-related variability was still moderate to large. The within-athlete within-cluster race-to-race variability was 0.3-1.3%, with a small difference in variability between male (0.8%) and female juniors (1.0%) and no difference between male and female seniors (both 0.6%). CONCLUSION The variability in performance times of skaters is similar to that of athletes in other sports in which air or water resistance limits speed. A performance enhancement of 0.1-0.4% by top-10 athletes is necessary to increase medal-winning chances by 10%.


The FASEB Journal | 2017

Critical determinants of combined sprint and endurance performance: An integrative analysis from muscle fiber to the human body

Stephan van der Zwaard; Willem J. van der Laarse; Guido Weide; Frank W. Bloemers; Mathijs J. Hofmijster; K. Levels; Dionne A. Noordhof; Jos J. de Koning; Cornelis J. de Ruiter; Richard T. Jaspers

Optimizing physical performance is a major goal in current physiology. However, basic understanding of combining high sprint and endurance performance is currently lacking. This study identifies critical determinants of combined sprint and endurance performance using multiple regression analyses of physiologic determinants at different biologic levels. Cyclists, including 6 international sprint, 8 team pursuit, and 14 road cyclists, completed a Wingate test and 15‐km time trial to obtain sprint and endurance performance results, respectively. Performance was normalized to lean body mass2/3 to eliminate the influence of body size. Performance determinants were obtained from whole‐body oxygen consumption, blood sampling, knee‐extensor maximal force, muscle oxygenation, whole‐muscle morphology, and muscle fiber histochemistry of musculus vastus lateralis. Normalized sprint performance was explained by percentage of fast‐type fibers and muscle volume (R2 = 0.65; P < 0.001) and normalized endurance performance by performance oxygen consumption (Vo2), mean corpuscular hemoglobin concentration, and muscle oxygenation (R2 = 0.92; P < 0.001). Combined sprint and endurance performance was explained by gross efficiency, performance Vo2 and likely by muscle volume and fascicle length (P = 0.056; P = 0.059). High performance Vo2 related to a high oxidative capacity, high capillarization x myoglobin, and small physiologic cross‐sectional area (R2 = 0.67; P < 0.001). Results suggest that fascicle length and capillarization are important targets for training to optimize sprint and endurance performance simultaneously.— Van der Zwaard, S., van derLaarse, W. J., Weide, G., Bloemers, F. W., Hofmijster, M. J., Levels, K., Noordhof, D. A., de Koning, J. J., de Ruiter, C. J., Jaspers, R. T. Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body. FASEB J. 32, 2110–2123 (2018). www.fasebj.org


International Journal of Sports Physiology and Performance | 2017

Historical Improvement in Speed Skating Economy.

Dionne A. Noordhof; Elmy van Tok; Florentine S.J.G.M. Joosten; Florentina J. Hettinga; M.J.M. Hoozemans; Carl Foster; Jos J. de Koning

Half the improvement in 1500-m speed-skating world records can be explained by technological innovations and the other half by athletic improvement. It is hypothesized that improved skating economy is accountable for much of the athletic improvement. PURPOSE To determine skating economy in contemporary athletes and to evaluate the change in economy over the years. METHODS Contemporary skaters of the Dutch national junior team (n = 8) skated 3 bouts of 6 laps at submaximal velocity, from which skating economy was calculated (in mL O2 ・ kg-1 ・ km-1). A literature search provided historic data on skating velocity and submaximal V̇O2 (in mL ・ kg-1 ・ min-1), from which skating economy was determined. The association between year and skating economy was determined using linear-regression analysis. Correcting the change in economy for technological innovations resulted in an estimate of the association between year and economy due to athletic improvement. RESULTS A mean (± SD) skating economy of 73.4 ± 6.4 mL O2 ・ kg-1 ・ km-1 was found in contemporary athletes. Skating economy improved significantly over the historical time frame (-0.57 mL O2 ・ kg-1 ・ km-1 ・ y-1, 95% confidence interval [-0.84, -0.31]). In the final regression model for the klapskate era, with altitude as confounder, skating economy improved with a nonsignificant -0.58 mL O2 ・ kg-1 ・ km-1 ・ y-1 ([-1.19, 0.035]). CONCLUSIONS Skating economy was 73.4 ± 6.4 mL O2 ・ kg-1 ・ km-1 in contemporary athletes and improved over the past ~50 y. The association between year and skating economy due to athletic improvement, for the klapskate era, approached significance, suggesting a possible improvement in economy over these years.


Journal of Sports Sciences | 2018

Muscle morphology of the vastus lateralis is strongly related to ergometer performance, sprint capacity and endurance capacity in Olympic rowers

Stephan van der Zwaard; Guido Weide; K. Levels; Michelle R. I. Eikelboom; Dionne A. Noordhof; Mathijs J. Hofmijster; Willem J. van der Laarse; Jos J. de Koning; Cornelis J. de Ruiter; Richard T. Jaspers

ABSTRACT Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates to rowing ergometer performance, sprint and endurance capacity of Olympic rowers. Eighteen rowers (12♂, 6♀, who competed at 2016 Olympics) performed an incremental rowing test to obtain maximal oxygen consumption, reflecting endurance capacity. Sprint capacity was assessed by Wingate cycling peak power. M. vastus lateralis morphology (volume, physiological cross-sectional area, fascicle length and pennation angle) was derived from 3-dimensional ultrasound imaging. Thirteen rowers (7♂, 6♀) completed a 2000-m rowing ergometer time trial. Muscle volume largely explained variance in 2000-m rowing performance (R2 = 0.85), maximal oxygen consumption (R2 = 0.65), and Wingate peak power (R2 = 0.82). When normalized for differences in body size, maximal oxygen consumption and Wingate peak power were negatively related in males (r = −0.94). Fascicle length, not physiological cross-sectional area, attributed to normalized peak power. In conclusion, vastus lateralis volume largely explains variance in rowing ergometer performance, sprint and endurance capacity. For a high normalized sprint capacity, athletes may benefit from long fascicles rather than a large physiological cross-sectional area.

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Carl Foster

University of Wisconsin–La Crosse

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K. Levels

VU University Amsterdam

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Guido Weide

VU University Amsterdam

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