Ultrasound-detected effusion-synovitis is associated with greater limb loading rate asymmetry during walking post-ACL reconstruction: A pilot study.

Objective: Chronic inflammation and altered walking biomechanics are common after ACL reconstruction (ACLR) and contribute to the development of osteoarthritis. Clinically accessible techniques are needed to monitor inflammation (ultrasound-assessed effusion-synovitis) and walking biomechanics (force-measuring insoles), and they must improve the translation of these assessments and determine whether inflammation and walking biomechanics are related in patients after ACLR. This study aimed to determine the association between ultrasound-detected knee effusion-synovitis and limb loading asymmetries during walking in patients 1-5 years post-ACLR. Design: 15 participants (9 women; age: 26 ± 6yrs; mass: 71 ± 15 kg; height: 173 ± 9 cm; months post-ACLR: 29 ± 13) were included in this cross-sectional study. Knee effusion-synovitis was assessed using a standardized protocol and graded using a validated scoring atlas (0 = absent, 1 = mild, 2 = moderate, 3 = severe) in the ACLR limb. Force-measuring insoles were used to capture the vertical ground reaction force (vGRF) during a one-minute treadmill walking trial. Limb symmetry indices (LSIs) were used to quantify limb loading asymmetry for the peak vGRF and the instantaneous loading rate (vGRF-LR). Spearman correlations determined whether effusion-synovitis grade was associated with peak vGRF and vGRF-LR LSI. Results: Effusion-synovitis was present in the ACLR limb of 13/15 (87 %) participants (Grade 0: n = 2; Grade 1: n = 8; Grade 2: n = 4, Grade 3: n = 1). Effusion-synovitis grade was not significantly associated with peak vGRF LSI (mean±sd: 98.0 ± 5.6; ρ = 0.38, p = 0.162), but was significantly associated with vGRF-LR LSI (98.2 ± 11.4; ρ = 0.55, p = 0.035). Conclusion: Most participants 1-5 years post-ACLR have ultrasound-detected effusion-synovitis. Participants with more severe effusion-synovitis load their ACLR limb more rapidly. This study highlights the utility of clinically accessible techniques in assessing inflammation and walking biomechanics in ACLR patients.

A self-selected 16:8 time-restricted eating quasi-experimental intervention improves various markers of cardiovascular health in middle-age male cyclists.

OBJECTIVES: Time-restricted eating (TRE) is a dietary intervention that may offer some protection against cardiovascular disease (CVD), while also preserving performance in athletes. To date however, research on TRE in an active population has only been conducted in college-age cohorts and the effects of TRE in an older, trained population are less understood. Therefore, the aim of this study was to compare the effects of a 4-wk, 16:8 TRE intervention on markers of CVD risk in middle-age, male cyclists. METHODS: Participants (N = 12; age, 51.9 ± 8.6 y; training duration/wk, 375 ± 140 min; peak aerobic capacity, 41.8 ± 5.6 mL/kg/min) reported to the laboratory for two sessions (i.e., at baseline and post-TRE) where blood was drawn from an antecubital vein after an 8-h overnight fast. Dependent variables measured at baseline and post-TRE included insulin, cortisol, brain-derived neurotropic factor, free testosterone, thyroxine, triiodothyronine, C-reactive protein, advanced oxidative protein products, glutathione, tumor necrosis factor (TNF)-α, glucose, and a full lipid profile. RESULTS: Compared with baseline, TRE significantly lowered TNF-α (12.3 ± 3.4 versus 9.2 ± 2.4 pg/mL; P = 0.02) and glucose concentrations (93.4 ± 9.7 versus 87.5 ± 7.9 mg/dL; P = 0.01), as well as significantly elevated high-density lipoprotein cholesterol levels (45.7 ± 13.7 versus 49.2 ± 12.3 mg/dL; P = 0.04), respectively. No further significant changes were observed between the remaining variables (all P > 0.05). CONCLUSION: Overall, these data suggest that incorporating a 4-wk TRE intervention with habitual endurance training can significantly improve some markers of CVD risk and may compliment the robust health benefits derived from a regular exercise regimen.

Astaxanthin Supplementation Does Not Affect Markers of Muscle Damage or Inflammation After an Exercise-Induced Muscle Damage Protocol in Resistance-Trained Males.

ABSTRACT: Waldman, HS, Bryant, AR, Parten, AL, Grozier, CD, and McAllister, MJ. Astaxanthin supplementation does not affect markers of muscle damage or inflammation after an exercise-induced muscle damage protocol in resistance-trained males. J Strength Cond Res 37(7): e413-e421, 2023-It is well documented that exercise-induced muscle damage (EIMD) decreases exercise performance by elevated inflammation and subjective discomfort. Due to its potent antioxidative properties, astaxanthin (AX) may serve as a potential dietary supplement strategy for mitigating delayed-onset muscle soreness (DOMS) and enhancing recovery and performance. This study aimed to investigate the effects of AX on markers of muscle damage, inflammation, DOMS, and anaerobic performance and substrate metabolism. Thirteen resistance-trained men (mean ± SD , age, 23.4 ± 2.1 years) completed a double-blind, counterbalanced, and crossover design with a 1-week washout period between 2, 4-week supplementation periods at 12 mg·d -1 of AX or placebo. After each supplementation period, subjects completed 2 trials, with trial 1 including a graded exercise test (GXT) and a 30-second Wingate and trial 2 including an EIMD protocol followed by the collection of fasting blood samples (pre-post) to measure creatine kinase, advanced oxidative protein products, C-reactive protein, interleukin-6, insulin, and cortisol. Astaxanthin supplementation had no statistical effects on markers of substrate metabolism during the GXT, Wingate variables, or markers of muscle damage, inflammation, or DOMS when compared with placebo (all p > 0.05). However, 4 weeks of AX supplementation did significantly lower oxygen consumption during the final stage of the GXT (12%, p = 0.02), as well as lowered systolic blood pressure (∼7%, p = 0.04), and significantly lowered baseline insulin values (∼24%, p = 0.05) when compared with placebo. Collectively, these data suggest that 4 weeks of AX supplementation at 12 mg·d -1 did not affect markers of muscle damage, inflammation, or DOMS after an EIMD protocol in a resistance-trained male cohort.

A Self-Selected 16:8 Time-Restricted Eating Protocol Improves Fat Oxidation Rates, Markers of Cardiometabolic Health, and 10-km Cycling Performance in Middle-Age Male Cyclists.

ABSTRACT: Witt, CR, Grozier, CD, Killen, LG, Renfroe, LG, O'Neal, EK, and Waldman, HS. A self-selected 16:8 time-restricted eating protocol improves fat oxidation rates, markers of cardiometabolic health, and 10-km cycling performance in middle-age male cyclists. J Strength Cond Res 37(5): 1117-1123, 2023-The purpose of this study was to assess the impact of 4 weeks, 16:8 time restricted eating (TRE) on markers of metabolic health and 10-km time trial (TT) performance in middle-age male cyclists. Subjects ( n = 12; age, 40-60 years; V̇ o2 peak, 41.8 ± 5.6 ml·kg -1 ·min -1 ) consisting of individuals following a habitual Western diet completed a familiarization and 2 experimental trials [PRE] and [POST]. Following habitual Western diet without TRE, anthropometric measures were assessed, followed by completion of a graded exercise test and 10-km TT. Subjects then adhered to a 4-week TRE protocol where all calories had to be consumed within a self-selected 8-hour window and then returned for repeat testing. Although self-reported caloric intake did not statistically change PRE to POST, body mass (PRE, 83.2 ± 13.4 vs. POST, 80.7 ± 12.6 kg), fat mass (∼2.5 kg), and blood pressure (systolic, 8 mm Hg; diastolic, 4 mm Hg) were all significantly lower POST (all p < 0.05), with no changes in fat-free mass. Furthermore, fat oxidation significantly increased (PRE, 0.36 ± 0.03 vs. POST, 0.42 ± 0.03 g·min -1 ; p = 0.04) following the TRE intervention and 10-km TT performance improved by ∼2 minutes POST (PRE, 29.7 ± 7.3 vs. POST, 27.4 ± 5.5 minutes; p = 0.02). Overall, our data demonstrated that middle-age male cyclists adhering to a 4-week TRE protocol can improve their body composition profile and 10-km TT performance without detriments to fat-free mass.

Four Weeks of Hericium erinaceus Supplementation Does Not Impact Markers of Metabolic Flexibility or Cognition.

Hericium erinaceus (HE), also known as Lion's Mane mushroom, has been found to enhance cognition and metabolic flexibility in various animal models. To date however, only four studies exist in humans and none have evaluated the effects of HE on markers of metabolic flexibility or cognitive performance. A single-blind, placebo controlled, parallel-longitudinal study was used to determine the effects of HE on markers of metabolic flexibility and cognition. Twenty-four participants completed a graded exercise test on a cycle ergometer to analyze substrate oxidation rates and markers of cardiorespiratory fitness. Additionally, two dual-task challenges consisting of a Stroop Word Challenge interspersed with a Mental Arithmetic Challenge were performed, pre-post the graded exercise test, to evaluate markers of cognition in a pre-post fatigued state. Participants were stratified into two groups, receiving either 10 g of HE per day or placebo for 4-weeks in the form of two muffins identical in taste and appearance. Repeated-measures analysis of variance were conducted to evaluate potential interactions or main effects. Although group differences were noted at baseline, there were no significant interactions or main effects observed from HE ingestion for any dependent variable (all p > 0.05). Our data suggest that ingesting 10 g of HE per day for 4-weeks had no impact on metabolic flexibility and cognition in a college-age cohort. Due to the limited research on HE supplementation, future research is needed to establish an effective supplement dose and duration for potential physiological changes to be observed in humans.

Gathering your 'sea legs': Extended durations in an offshore environment increases postural sway excursions.

BACKGROUND: Mal de debarquement (MdD), or often called 'sea legs', is the perception of self-motion after exposure to passive movement such as being on a boat at sea. Previous studies highlight sensory re-organization difficulties and postural control impairments after disembarking from sea travel in experienced crew members. However, the impact of MdD in individuals with minimal offshore experience, defined as participating in less than 2 offshore excursions per year, has not been investigated. RESEARCH QUESTION: Does exposure to boat motion while at sea alter static postural control after disembarking in individuals with minimal offshore experience? METHODS: Healthy adults (n = 24) with minimal offshore experience had their static balance assessed on a force platform before (PRE) and after (POST) a 7-h deep sea fishing excursion. Static balance was tested in eyes open (EO), eyes closed (EC), eyes open on a foam surface (EOF), and eyes closed on a foam surface (ECF) conditions. Sway excursions, sway velocity and sway variability in the medial-lateral (ML) and anterior-posterior (AP) directions were computed and then compared PRE/POST using a paired t-test (p < 0.05). RESULTS: Significant increases in ML sway excursion (p = 0.004), ML sway range (p < 0.001), ML sway variability (p < 0.001), AP sway excursion (p = 0.045), AP sway range (p = 0.020), and AP sway variability (p = 0.030) were observed at POST during EOF. Significant increases in ML sway excursion (p = 0.027), AP sway excursion (p = 0.020), and AP sway variability (p = 0.014) at POST were also observed during ECF. No differences were found in the EO condition (p > 0.05). SIGNIFICANCE: Increases in postural sway excursion and variability were observed in individuals with minimal offshore experience after disembarking. Our findings suggest sensory re-organization difficulties in order to maintain an upright posture in challenging sensory conditions are dependent on vestibular and somatosensory inputs following exposure to boat motion at sea.

Effects of medial longitudinal arch flexibility on propulsion kinetics during drop vertical jumps.

This study examined the effects of medial longitudinal arch (MLA) flexibility on kinetics during the eccentric and concentric subphases of a drop vertical jump (DVJ). Physically active adults with flexible (n = 16) and stiff (n = 16) MLA completed DVJs onto a force platform from a height of 30 cm. Eccentric and concentric subphases of the DVJ were identified from the vertical ground reaction force (GRF) data. Jump height, ground contact time, reactive strength index (RSI), vertical center-of-mass depth, vertical stiffness and time of the eccentric and concentric subphases were evaluated. Amortization force, peak vertical GRF and vertical impulse were also obtained for the eccentric and concentric subphases of the DVJ. Dependent variables were compared between groups using independent samples t-tests (p < 0.05). Significantly greater vertical stiffness (p = 0.048; ES = 0.63) was found in the stiff arch group (-173.91 ± 99.73 N/kg/m) compared to the flexible arch group (-122.95 ± 63.42 N/kg/m). A moderate-magnitude difference (ES = 0.58) was observed for RSI between flexible (0.89 ± 0.39) and stiff arch (1.20 ± 0.70) groups, but was not significant (p = 0.063). The active and passive structures supporting the MLA may be used differently to achieve similar vertical jump height during a DVJ. Additional research is warranted to further understand the contributions of MLA flexibility to jumping performance.