Jake A. Deckert

Instrument-assisted soft tissue mobilization: Effects on the properties of human plantar flexors

The effect of instrument-assisted soft tissue mobilization (ISTM) on passive properties and inflammation in human skeletal muscle has not been evaluated. Passive properties of muscle, inflammatory myokines and subjective reporting of functional ability were used to identify the effects of ISTM on the plantar flexors. 11 healthy men were measured for passive musculotendinous stiffness (MTS), passive range of motion (PROM), passive resistive torque (PASTQ) and maximum voluntary contraction peak torque (MVCPT) for plantar flexor muscles of the lower leg. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured from muscle biopsies from the gastrocnemius, and subjective measurements of functional ability were taken using the perception of functional ability questionnaire (PFAQ). MTS, PROM, PRT and MVCPT were measured in the treatment leg (TL) and control leg (CL) before, immediately after, 24 h, 48 h and 72 h following IASTM. Biopsies for IL-6 and TNF-α and PFAQ responses were collected before as well as 24 h, 48 h and 72 h after IASTM. There were no significant differences in MTS, PROM, PASTQ, MVCPT, IL-6 and TNF-α between the TL or CL. A significant decrease in the perception of function and a significant increase in pain for the TL were found following IASTM.

Reminder: RMSSD and SD1 are Identical Heart Rate Variability Metrics.

Assessment of heart rate variability (HRV) is a common approach to examine cardiac autonomic nervous system modulation that has been employed in a variety of settings. Frequently, both the root mean square of successive differences (RMSSD) and SD1, which is a Poincaré plot component, have been used to quantify short‐term heart rate variability. It is not typically appreciated, however, that RMSSD and SD1 are identical metrics of HRV. As a reminder to clinicians and researchers who use and study HRV, we show both empirically and mathematically that RMSSD and SD1 are identical metrics. Because the homology between RMSSD and SD1 is not commonly known, the inclusion of both measures has been reported in many recent publications. The inappropriate use of such redundant data may affect the interpretation of HRV studies. Muscle Nerve 56: 674–678, 2017

Perception of Exercise-Induced Bronchoconstriction in College Athletes

BACKGROUND: Exercise-induced bronchoconstriction (EIB) can lead to long-term respiratory illness and even death. EIB prevalence rates are both high and variable in college athletes. Also, prevalence rates may be underestimated due to ineffective screening. The purpose of this study is to investigate the prevalence of EIB and the perceived impact of EIB in college athletes via a self-report questionnaire. METHODS: A self-report EIB questionnaire was administered to college athletes on 8 different sports teams. Information collected was used to identify athletes who self-reported: (1) a history of EIB and/or asthma, (2) respiratory symptoms during exercise, (3) medication use, and (4) concern about EIB. RESULTS: Results showed that 56 of 196 athletes (28.6%) self-reported a history of EIB or asthma. Over half (52%) reported a history of EIB/asthma or current EIB symptoms. Forty-six of the 140 athletes (32.9%) who did not report a history of EIB or asthma indicated symptoms of EIB during sports, training, or exercise. Fourteen of 56 athletes (25%) self-reporting a history of EIB or asthma did not report the use of a respiratory medication. Nineteen of 196 athletes (9.7%) reported being concerned that EIB was adversely affecting their sports performance. CONCLUSIONS: College athletes self-report a high prevalence of EIB or asthma. Although college athletes may not report a history of EIB or asthma, they indicate symptoms of EIB. A majority of athletes reported a history or current symptoms related to EIB or asthma. Many athletes with a history of EIB or asthma are not taking any asthma medication. Last, athletes report concern about EIB adversely affecting their sports performance. More work is needed using a combination of a screening questionnaire and standardized EIB testing to develop a validated tool for accurately screening and diagnosing EIB in college athletes.

Immunoendocrine alterations following Marine Corps Martial Arts training are associated with changes in moral cognitive processes

Combined physical and psychological stress events have been associated with exacerbated endocrine responses and increased alterations in immune cell trafficking when compared to exercise stress alone. Military training programs are rigorous in nature and often purposefully delivered in environments combining high levels of both physical and mental stress. The objective of this study was to assess physiological and cognitive changes following U.S. Marine Corps Martial Arts training. Seven active-duty, male Marines were observed during a typical Marine Corps Martial Arts training session. Immune parameters, including immunomodulatory cytokines, and hormone concentrations were determined from blood samples obtained at baseline, immediately post training (IP) and at 15min intervals post-training to 1h (R15, R30, R45, R60). Assessments of cognitive moral functioning (moral judgment and intent) were recorded at intervals during recovery. There were significant fluctuations in immunoendocrine parameters. Peak endocrine measures were observed within the IP-R15 time interval. Distributions of circulating immune cells were significantly altered with neutrophils and all lymphocyte subsets elevated at IP. IFN-γ and IL-17a exhibited small, non-significant, parallel increases over the recovery period. Moral functioning was informed by different social identities during the recovery resulting in changes in moral decision-making. These data demonstrate that the Marine Corps Martial Arts Program induces significant alterations in lymphocyte and leukocyte distributions, but does not shift the balance of Th1/Th2 cytokines or induce a systemic inflammatory response. The program does, however, induce alterations in moral decision-making ability associated with the observed endocrine responses, even suggesting a potential interaction between ones social identities and endocrine responses upon moral decision-making.

T Cell Activation and Proliferation Following Acute Exercise in Human Subjects is Altered by Storage Conditions and Mitogen Selection

Recent work investigating exercise induced changes in immunocompetence suggests that some of the ambiguity in the literature is resultant from different cell isolation protocols and mitogen selection. To understand this effect, we compared post-exercise measures of T cell activation and proliferation using two different stimulation methods (costimulation through CD28 or stimulation with phytohaemagglutinin [PHA]). Further, we investigated whether exercise induced changes are maintained when T cell isolation from whole blood is delayed overnight in either a room temperature or chilled (4°C) environment. As expected, an increased proliferation response was observed post-exercise in T cells isolated from whole blood of previously trained individuals immediately after blood collection. Also, cells stimulated with PHA after resting overnight in whole blood were not adversely impacted by the storage conditions. In contrast, allowing cells to rest overnight in whole blood prior to stimulation through CD28, lessened the proliferation observed by cells following exercise rendering both the room temperature and chilled samples closer to the results seen in the control condition. Changes in early markers of activation (CD25), followed a similar pattern, with activation in PHA stimulated cells remaining fairly robust after overnight storage; whereas cell activation following stimulation through CD3+CD28 was disproportionately decreased by the influence of overnight storage. These findings indicate that decisions regarding cell stimulation methods need to be paired with the timeline for T cell isolation from whole blood. These considerations will be especially important for field based studies of immunocompetence where there is a delay in getting whole blood samples to a lab for processing as well as clinical applications where a failure to isolate T cells in a timely manner may result in loss of the response of interest.

Methodological Differences in the Interpretation of Fatigue Data from Repeated Maximal Effort Knee Extensions

Background : Isokinetic fatigue protocols are commonly used in both research as well as in kinesiology education. However, fatigue quantification methods vary between studies. Objective : Therefore, the purpose of this study was to determine how fatigue quantification methods affect data interpretation and which methods may be most appropriate. Method : In this study, we quantified fatigue from a repeated maximal effort isokinetic knee extension test using different methods, as seen in published research. Nine healthy males and nine healthy females performed 50 concentric knee extensions at 180°•s-1. For each repetition, torque was quantified as either peak torque (PT), torque at the mid-point of the range of motion, and torque integrated over the full, middle 30° range of motion, and isokinetic range of motion. Fatigue Index was quantified using either the first and last three or five repetitions or the peak and last three or five repetitions. Torque slopes were quantified using all repetitions or repetitions that occurred at and beyond the repetition at which the greatest torque value occurred. Results : There was a significant inverse relationship between angle at PT and repetition number. Measures of fatigue were overestimated when torque integral over the isokinetic range of motion was utilized. When the first three or first five repetitions were utilized for Fatigue Index calculations, fatigue was underestimated. Conclusion : Results suggest that torque integral over the full range of motion is likely the best representation of strength or work. Also, researchers should omit the first few repetitions from their quantification of Fatigue Index or torque slope.