Carnosine content of gastrocnemius muscle in male and female active elite runners, according to their best running distance.

<p>All male (n = 22) and female (n = 12) elite runners were ranked according to their best running distance (using the IAAF scoring tables of athletics). The X-axis displays running distance (m) in a logarithmic fashion and the Y-axis shows the carnosine content, expressed in Z-scores. A Y-value of zero corresponds to the average of the male/female reference population. The median Z-score per group is shown and the best sigmoidal fit is presented.</p

Carnosine content of gastrocnemius muscle in track-and field and triathletes compared to an untrained male control population.

<p>Muscle carnosine content (mM) in various small groups of male elite athletes (n = 39) and in a male control population (n = 47) ranked from low to high. Numbers per group are demonstrated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021956#pone-0021956-g001" target="_blank">figure 1</a>. The primary X-axis shows the measured carnosine content, while the secondary X-axis displays the estimated percentage area occupied by type II fibers (derived from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021956#pone-0021956-g002" target="_blank">figure 2</a>). The vertical line represents the median of the male control population. Medians (small vertical lines) and first and third quartile are shown by group.</p

Overview of subject population.

<p>Numbers of subjects per group and by gender is shown. Muscle carnosine content is measured of all 163 subjects and muscle biopsies were taken from 12 not specifically trained males.</p

Summary of the activation clusters in the whole-brain contrasts.

<p>(*) voxel-level threshold p = 0.0001 uncorrected.</p><p>Legend: p(FWE)-cor = cluster-level family-wise error corrected p-values. SVC = small volume corrected. For regions including multiple local maxima, the highest local maximum is reported.</p

fMRI Results.

<p>a. Reward contrast (big reward>small reward). Activation clusters are located in the posterior cingulate cortex (PCC), anterior cingulate cortex (ACC), striatum and superior frontal gyrus (SFG). b. Effort contrast (high effort>low effort). Activation clusters are located in the posterior cingulate cortex (PCC), brainstem, anterior cingulate cortex (ACC), insula, striatum and middle frontal gyrus (MFG). c. Conjunction of high effort>low effort & big reward>small reward. Overlapping activation clusters are located in the striatum, anterior cingulate cortex (ACC) and precuneus. d. Short delay>long delay contrast. The activation cluster is located in the left orbitofrontal cortex (OFC). e. Effort-selective activation ((high effort>low effort)>(high reward> low reward)), SVC for the region of the brainstem, p value 0.05 FWE correction for multiple comparisons, plotted on Proton Density Weighted MRI Template (left image). f. Parameter estimates plot at voxel −4, −32, −10 (MNI coordinates), local maximum in the activation cluster located in the Brainstem in the effort-selective contrast.</p

Task structure and behavioral performance.

<p>a. Block types. In every block only one trial type is presented, where only one feature is manipulated. In a trial in the reward block, the cue informs about the final reward being small or big. In a trial in the effort block, the cue informs about the difficulty level (low or high). In the delay block, the cue informs about the length of the delay between response and reward delivery (short or long). b. Task structure and timing. The cue presentation is followed by a fixation symbol. The task follows, consisting of an addition followed by a subtraction. Two possible results are presented and the subject has to choose the correct one. After the response, a delay can occur. If the response was accurate, the reward is shown. c. Average rating of pleasantness for every cue-type (small reward cue, big reward cue, low effort cue, high effort cue, short delay cue, long delay cue). e. Average reaction times (RTs) in every condition (small reward, big reward, low effort, high effort, short delay, long delay). RT in the high effort condition is significantly higher than in the low effort condition (p<0.001).</p

Comparison of the gastrocnemius carnosine content in male young talented athletes (n = 15), active elite athletes (n = 19) and ex-athletes (n = 14).

<p>The Y-axis demonstrates the carnosine content in millimolar (mM). Diamonds represent explosive athletes, including sprinters and jumpers (talents n = 7; active n = 12 ; ex n = 7) and squares endurance runners (talents n = 8; active n = 7; ex n = 7). Data are shown as means ± standard deviation. * Different from explosive athletes (p≤0.05).</p

Correlation between muscle carnosine content and percentage area occupied by type-II fibers in 12 untrained subjects.

<p>The X-axis displays the percentage of the total area occupied by type-II fibers. The muscle carnosine content in millimolar (mM) is shown on the Y-axis. A significant (p = 0.009 and r = 0.714) positive correlation between muscle carnosine content and percentage area occupied by type-II fibers is demonstrated.</p

List of regions resulting from the overlap of the Reward and Effort contrast, thus responding to both anticipation of high effort and big reward.

<p>List of regions resulting from the overlap of the Reward and Effort contrast, thus responding to both anticipation of high effort and big reward.</p

Comparison of the mean Dice-scores and their standard deviation between different initialization methods for the UZ Leuven dataset.

<p>The highest Dice-score per NMF method and per tissue class is marked in bold. * indicates statistically significantly higher Dice-scores with SPA initialization compared to direct SPA endmember extraction (right column), using a one-tailed Wilcoxon signed rank test (<i>p</i> < 0.05).</p