The purpose was to determine if the muscle swelling, echo intensity, and fatigue responses to blood flow restriction differs based on cuff width (Experiment 1), applied pressure (Experiment 2), and sex. Ultrasound of muscle was taken before and after exercise. In Experiment 1 (n = 96), men swelled more than women and more with a narrow cuff than a wide cuff (0.60 cm vs. 0.52 cm). Expressed as a percentage change, there were no longer differences between cuffs (Narrow: 15% vs. Wide: 14%) or sex (Men: 14% vs. Women: 15%). Echo intensity remained unchanged. Women required more repetitions to reach task failure in sets 2, 3, and 4. In Experiment 2 (n = 87), men swelled more than women (Men: 0.46 cm vs. Women: 0.31 cm). Expressed as a percentage change, there were no differences. Echo intensity decreased in both conditions and to a greater extent with a higher applied pressure. If the acute muscle swelling response is important for initiating long term adaptation, then our results indicate that neither cuff width, sex, nor applied pressure will differentially impact the adaptation observed via this mechanism. Changes in echo intensity were inconsistent and the utility of this measurement may need to be reconsidered.

To determine the agreement between the Open Barbell (OB) and Tendo weightlifting analyzer (TWA) for measuring barbell velocity, eleven men (19.4 ± 1.0 y) performed one set of 2–3 repetitions at four sub-maximal percentage loads, [i.e., 30, 50, 70, and 90% one-repetition maximum (1RM)] in the back (BS) and front squat (FS) exercises. During each repetition, peak and mean barbell velocity were recorded by OB and TWA devices, and the average of the 2–3 repetitions was used for analyses. Although the repeated measures analysis of variance revealed significantly (p ≤ 0.005) greater peak and mean velocity scores from OB across all intensities, high intraclass correlation coefficients (ICC_2,K = 0.790–0.998), low standard error of measurement (SEM_2,K = 0.040–0.119 m·s⁻¹), and coefficients of variation (CV = 2–4%) suggested consistency between devices. Positive (r = 0.491–0.949) Pearson correlations between averages and differences (between devices) in peak velocity, as well as associated Bland-Altman plots, showed greater differences occurred as the velocity increased, particularly at low-moderate intensity loads. OB consistently provides greater barbell velocity scores compared to TWA, and the differences between devices were more apparent as the peak velocity increased with low-to-moderate loads. Strength coaches and athletes may find better agreement between devices if the mean velocity scores are only considered.

It is suggested that experience is needed in order to capture valid estimates of muscle size with ultrasound. However, it is unknown whether there is a large degree of skill needed to analyze the images once they are captured. Objective. To determine if less experienced raters could accurately analyze ultrasound images of the forearm by comparing their estimates with those of a very experienced ultrasonographer (criterion). Approach. 50 muscle thickness images were captured by one experienced ultrasonographer (also Rater 1). Those images were saved and were then measured by four raters with different levels of experience. The rater who captured the images was very experienced (criterion), the second rater was also experienced and provided 5 minutes of instruction for Rater 3 (minimal experience) and Rater 4 (no experience). Test-retest reliability was also determined for Rater 3 and 4. Main Results. The average muscle thickness value for the criterion was 3.73 cm. The constant error for Rater 2, 3, and 4 was −0.003 (0.02) cm ( p = 0.362), −0.07 (0.04) cm ( p < 0.001), and 0.02 (0.09) cm ( p = 0.132), respectively. The SD for Rater 4 was greater, resulting in wider limits of agreement compared to Rater 2 and 3. Absolute error was 0.01 cm for Rater 2, whilst it was 0.07 cm and 0.03 cm for the two inexperienced raters (Rater 3 and 4). The error for Rater 3 was systematic and post-hoc assessment found that this rater was using a different border than the other three raters (but consistent across time). For the test-retest reliability, the minimal difference for Rater 3 was 0.08 cm (relative minimal difference of 2%) and 0.17 cm (relative minimal difference of 4%) for Rater 4. Significance. Less experienced raters were able to accurately and reliably analyze already captured muscle thickness images of the forearm with low absolute errors.

Myocardial infarction (MI) causes a robust inflammatory response, which is necessary for remodeling and scar formation of the infarcted left ventricle (LV). However, this can lead to chronic systemic inflammation and persistent autoimmune responses. In this study, we analyzed sex differences in the inflammatory autoimmune response to chronic MI. MI was induced by permanent left coronary artery ligation in adult male and female C57BL/6J mice for one, four, and eight weeks. Both sexes exhibited similar declines in LV function. Females had higher levels of total immune cells and T cells in the infarct and remote area at D7 post-MI, and B cells at D56. MI increased levels of pro-inflammatory cytokines (Il1b, Il6, Tnf, Ccl2, Ifng, Il18) in the LV infarct that peaked at one week, which was exaggerated in females for Il6, Ifng, and Il10. In the remote LV, females had higher levels of Il6, Tnf, Ccl2, and Il18. MI increased spleen mass in females only, and splenic cytokines were higher in females at several time points, including Il1b, Il12a, Il10, Ifng, Il18, Ccl2, and Il4. IgG and IgM deposition in the LV infarct increased over time in both sexes, but more so in females. In the remote area, both sexes had increased IgG and IgM at eight weeks. Plasma IgM was higher in females at one, four, and eight weeks post-MI compared with males. Plasma IgG and IgM autoantibodies were detected in males and females after MI, but the number of autoantibodies displaying reactivity to autoantigens was much higher in females, particularly at week 8. In summary, MI leads to the development of systemic and myocardial autoimmune activation, which is more pronounced in females.