The relationship between cardiac damage biomarkers and heart rate variability following 60 min of running.

PURPOSE: Endurance exercise may cause transient alterations in cardiac tissue. The number of studies evaluating the relationship between changes in heart rate variability (HRV) and cardiac biomarkers following an endurance event is limited. We hypothesized that there would be a time-dependent correlation between biomarkers of cardiac damage and the reduction in parasympathetic indices of HRV within 24 h after 60 min of running in middle-aged recreational runners. METHODS: The trained, middle-aged runners who participated in this study ran 60 min at a half-marathon pace on a treadmill. Blood samples (before and 0, 4, and 24 h after the running test) and HRV data (before and 0, 1, 4, and 24 h after the running test) were obtained. RESULTS: After running, cardiac biomarkers (total creatine kinase, cardiac isoform of creatine kinase, creatine kinase-index [CK-Index], cardiac troponin [cTnI]) increased significantly, and HRV measures related to parasympathetic nervous system activity decreased significantly; these measures returned to baseline levels within 24 h. Finally, there were significant correlations (all p < 0.05) between the change (4 h post-running vs. pre-running) in the CK-Index and the changes (post- vs pre-running) in time-domain and nonlinear measures of HRV (r - 0.61 to - 0.67). In addition, significant correlations (all p < 0.05) were found between the area under the cTnI curve and change (1-h post- and pre-running) in time-domain and nonlinear measures of HRV (r - 0.48 to - 0.51). CONCLUSIONS: The correlation between HRV and cardiac biomarkers indicates that HRV analysis may be an alternative approach to determine the magnitude of cardiac stress after endurance exercises.

Effects of a supervised therapeutic exercise program on musculoskeletal health and gait in patients with haemophilia: A pilot study.

INTRODUCTION: Episodes of bleeding in patients with haemophilia (PwH) are associated with haemophilic arthropathy, limitations in physical performance, reduced quality of life (QoL), and gait disorders. AIM: This non-randomized, controlled, interventional, prospective, single-centre pilot study aimed to assess the effects of an 8-week supervised therapeutic exercise program on musculoskeletal health, gait kinematic parameters (GKP), functional capacity, and QoL in adult PwH. METHODS: Nineteen PwH were allocated to an exercise group (n = 10) or a control group (n = 9). The patients in the exercise group followed an 8-week supervised therapeutic exercise program. The Haemophilia Joint Health Score (HJHS), a two-dimensional video-based gait kinematic analysis (2D-GKA), the 6-min walking test (6MWT), and the Haemophilia Quality of Life Questionnaire for Adults (Haem-A-Qol) were used as the outcome measures at baseline, after the exercise program (at the 8th week), and at the 6th-month follow-up. RESULTS: A significant improvement was observed in the exercise group in the HJHS-Total and Haem-A-Qol Total scores and the 6MWT value after the exercise program. Moreover, the 2D-GKA revealed improvement in most of the GKP (knee extension during the midstance and late swing phases, ankle dorsiflexion during the midstance phase, and ankle plantar flexion during the preswing phase). However, the gain obtained by the exercise program was not maintained at the 6th-month follow-up for the HJHS-Total and Hem-A-QoL-Total scores and GKP. CONCLUSION: The 8-week supervised therapeutic exercise program was successful in achieving improvement in joint health, GKP, functional capacity, and QoL in PwH.

Effect of Regular Aerobic Training on Serum C-Reactive Protein and IL-6 Levels in Obese Women.

OBJECTIVE: This study's objective was to evaluate interleukin-6 (IL-6) and C-reactive protein (CRP) responses and performance changes in obese women after 8 weeks of aerobic training with an intensity of 50 to 60% of their individual maximum oxygen uptake (VO2). METHODS: A total of 18 sedentary women with an average age of 44.3 (± 1.9) years volunteered for this study. Over a period of 8 weeks, in 4 40-minute sessions per week, the participants walked at an exercise intensity that caused their heart rates to increase to levels corresponding to 50 to 60% of their VO2 peaks. Blood samples were collected from the participants, both when they were at rest and a couple of minutes after the end of the 1st exercise session. Sampling was repeated in the 4th and 8th weeks, before and after the last training sessions. RESULTS: The participants' body mass indices and weights decreased significantly by the end of the 8th week, while their maximum running speeds and VO2 peaks increased significantly. There were no differences in CRP or IL- 6 concentrations between the pre- and post-training sessions, but most of the participants' IL-6 levels dropped below 10 pg/ml after 8 weeks of training. CONCLUSION: Although no significant changes were observed in CRP or IL-6 concentrations, it is important to note that in response to aerobic training, the IL-6 levels of most of the participants fell to what is generally considered acceptable.

The effects of exercise on skeletal and heart muscle citrate synthase and carnitine palmitoyltransferase mRNA expressions in high-calorie fed rats.

In this study, the effect of high-calorie feeding and aerobic exercise on skeletal and cardiac muscle citrate synthase (CS), carnitine palmitoyltransferase-I (CPT-I), and -II (CPT-II) mRNA expressions were evaluated. Genetically non-obese rats were grouped as normal-high calorie and sedentary-exercising. Gastrocnemius-soleus and heart muscles' CS, CPT-I, and CPT-II expressions and skeletal muscles' histopathological characteristics were evaluated. High-fat diet had increased body weight by 10% and aerobic exercise did not make any difference. Skeletal muscle CS expression was increased significantly in normal-calorie exercising group. Exercise and high-fat diet did not change CPT-I and CPT-II expressions in both heart and skeletal muscle. Histopathological evaluations demonstrated increased cytoplasmic lipid droplets in high-calorie fed sedentary rats, and exercise had reduced lipid droplets in skeletal muscle. Also, both mitochondria and nuclei distribution were impaired in high-calorie groups. In conclusion, aerobic exercise without food restriction was not enough to make significant changes in fat transportation mechanism into skeletal and heart muscle.

The Effects of Upper Extremity Isokinetic Strengthening in Post-Stroke Hemiplegia: A Randomized Controlled Trial.

OBJECTIVE: The aim of this study was to evaluate the efficacy of isokinetic strengthening in paretic upper extremity among patients with post-stroke hemiplegia. METHODS: Hemiplegic patients with at least 6 months post-stroke and those with arm and hand Brunnstrom motor recovery stage ≥ 3 were included to the study. Patients were randomized into two groups. Isokinetic training group received 4 weeks (3 days/week) of isokinetic strengthening, while the control group was tailored strengthening exercises with exercise bands. Outcome measures were the isokinetic peak torque of wrist flexor and extensors, Fugl-Meyer Assessment of upper extremity, Stroke Impact Scale (SIS), Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, hand grip strength, peak isometric strength of wrist flexor and extensors. Outcome measures were evaluated before treatment, after treatment (at the end of week 4) and 4 weeks after the end of treatment (at the end of week 8). The trial was registered at ClinicalTtrials.gov (ID: NCT03834311). RESULTS: After 4 weeks, changes in extensor peak torque at 60°/sn (p=0.007) and extensor peak isometric muscle strength (p=0.007) were higher in the isokinetic group (n=12) than those in the control group (n=12). At the end of week 8, only DASH score revealed a significantly higher improvement in the isokinetic group than that in the control group (p=0.014). CONCLUSIONS: Isokinetic strengthening may provide motor and functional improvement in paretic upper extremity among patients with post-stroke hemiplegia.

A Comparison of the Maximal Fat Oxidation Rates of Three Different Time Periods in The Fatmax Stage.

This study aimed to compare the maximal fat oxidation (MFO) rates obtained from the stage average, last 2 min average, and highest value in the Fatmax stage determined with a 6 min step protocol. A total of 35 overweight, sedentary healthy men (age: 25.4 ± 0.7 years, body mass index: 26.0 ± 0.6 kg/m2) participated in the study. Substrate oxidation was calculated using breath-by-breath gas exchange data for each stage. When the change in the fat oxidation rate for every min throughout the Fatmax stage was evaluated, the average value of the 4th min was significantly lower than that of the 2nd and 3rd min (p < 0.01). In addition, the 5th and 6th min fat oxidation rates were significantly lower than the rates of the 1st, 2nd, 3rd, and 4th min (0.30 ± 0.01 and 0.29 ± 0.01 g/min for the 5th and 6th min, respectively, vs. 0.35 ± 0.02, 0.34 ± 0.02, 0.33 ± 0.02, and 0.31 ± 0.01 g/min for the 1st, 2nd, 3rd, and 4th min, respectively; p < 0.01). Most of the participants had MFO rates in the 1st min of the stage (16/35 participants), and the MFO rates of the remaining participants were observed in the 2nd, 3rd, and 4th min (7/35, 4/35, and 8/35 participants, respectively). None of the participants had MFO rates in the 5th or 6th min. The individual MFO rate (highest fat oxidation rate during Fatmax) was significantly higher than the fat oxidation rate calculated with the last 2 min average values (0.36 ± 0.02 and 0.30 ± 0.01 g/min, respectively; p < 0.05). In conclusion, the calculation of the fat oxidation rate by averaging the last portion of the Fatmax stage data may cause the underestimation of the MFO rate, which probably occurs earlier in the Fatmax stage.