Brachial and carotid hemodynamic response to hot water immersion in men and women

This study sought to compare the brachial and carotid hemodynamic response to hot water immersion (HWI) between healthy young men and women. Ten women (W) and 11 men (M) (24±4 y) completed a 60 min HWI session immersed to the level of the sternum in 40°C water. Brachial and carotid artery hemodynamics (Doppler ultrasound) were measured at baseline (seated rest) and every 15 min throughout HWI. Within the brachial artery, total shear rate was elevated to a greater extent in women (+479 [+364, +594] sec-1 than men (+292 [+222, +361] sec-1) during HWI (P = 0.005). As shear rate is inversely proportional to blood vessel diameter and directly proportional to blood flow velocity, the sex difference in brachial shear response to HWI was the result of a smaller brachial diameter among women at baseline (P < 0.0001) and throughout HWI (main effect of sex: P < 0.0001) and a greater increase in brachial velocity seen in women (+48 [+36, +61] cm/sec) compared to men (+35 [+27, +43] cm/sec) with HWI (P = 0.047) which allowed for a similar increase in brachial blood flow between sexes (M: +369 [+287, +451] mL/min, W: +364 [+243, +486] mL/min, P = 0.943). In contrast, no differences were seen between sexes in carotid total shear rate, flow, velocity, or diameter at baseline or throughout HWI. These data indicate the presence of an artery-specific sex difference in the hemodynamic response to a single bout of HWI.

Effect of Heat Stimulation on Circulating Irisin in Humans

High temperatures lead to oxidative stress. The aim of the study was to determine whether heat stimulation-induced hyperthermia can increase the level of circulating irisin. Twenty-one healthy female subjects (age, 26.3 ± 2.71 years; height, 162.1 ± 3.15 cm; weight, 54.2 ± 3.86 kg; and body surface area, 1.57 ± 0.11 m2) not taking contraceptives participated in this study. All experiments were performed individually for each participant when they were in the early proliferative menstrual phase. In an automated climate chamber (25 ± 0.5°C), the heat load was applied via half-body immersion into a hot water bath (42 ± 0.5°C). Five-minutes break was provided every after 5 min of immersion and the total passive heating time was 30 min. Tympanic temperature (Tty) and skin temperature (Ts) were measured. Mean body temperature (mTb) was calculated. Blood samples were collected before and immediately after immersion. Levels of irisin, cortisol, creatine kinase (CK), and lactate dehydrogenase (LDH) were analyzed. Tty, mTb and serum irisin levels increased after hot water immersion. The blood levels of cortisol, CK, and LDH were also elevated after hot water immersion. Heat stimulation might increase the levels of circulating irisin in humans in response to oxidative stress.

Potensi Infusa Kemiri (Aleurites moluccana) sebagai Analgesik dan Stimulator Stamina

Kesehatan merupakan hal penting untuk menjalankan aktivitas sehari-hari. Penurunan kesehatan dan daya tahan tubuh mengakibatkan timbul rasa nyeri serta mudah terserang penyakit. Pengobatan herbal digunakan sebagai pengobatan alternatif yang lebih aman dan terjangkau dibandingkan pengobatan nonherbal dari bahan-bahan kimia. Kemiri merupakan salah satu tanaman herbal yang memiliki banyak khasiat dan sering digunakan sebagai pengobatan oleh masyarakat. Penelitian ini bertujuan mempelajari efektivitas infusa kemiri sebagai analgesik dan stimulator stamina dalam berbagai dosis pada mencit. Uji efektivitas analgesik ditinjau menggunakan metode hot water immersion tail-flick test dan uji efektivitas stamina menggunakan metode natatory enhausen. Penelitian ini menggunakan 20 ekor mencit jantan yang dikelompokkan menjadi kelompok kontrol dan kelompok perlakuan yang diberi infusa kemiri dengan dosis 1, 2, dan 4 g/kg BB. Setiap kelompok terdiri atas 5 ekor. Data dianalisis menggunakan analysis of variance (ANOVA) kemudian dilanjutkan dengan uji Tukey. Hasil penelitian didapatkan dosis efektif pada uji analgesik adalah 4 g/kg BB dengan waktu respons nyeri ekor terlama yaitu 7.840±0.477 detik dan pada uji stamina adalah 1 g/kg BB yang ditunjukkan dengan durasi berenang terlama yaitu 145.00±20.65 detik. Kemiri memiliki efektivitas terhadap analgesik dan stimulator stamina.

Local cooling during hot water immersion improves perceptions without inhibiting the acute interleukin-6 response

Purpose Passive elevation of body temperature can induce an acute inflammatory response that has been proposed to be beneficial; however, it can be perceived as uncomfortable. Here, we investigate whether local cooling of the upper body during hot water immersion can improve perception without inhibiting the interleukin-6 (IL-6) response. Methods Nine healthy male participants (age: 22 ± 1 years, body mass: 83.4 ± 9.4 kg) were immersed up to the waist for three 60-min water immersion conditions: 42 °C hot water immersion (HWI), 42 °C HWI with simultaneous upper-body cooling using a fan (FAN), and 36 °C thermoneutral water immersion (CON). Blood samples to determine IL-6 plasma concentration were collected pre- and post-water immersion; basic affect and thermal comfort were assessed throughout the intervention. Results Plasma IL-6 concentration was higher for HWI and FAN when compared with CON (P < 0.01) and did not differ between HWI and FAN (P = 0.22; pre to post, HWI: 1.0 ± 0.6 to 1.5 ± 0.7 pg·ml−1, FAN: 0.7 ± 0.5 to 1.1 ± 0.5 pg·ml−1, CON: 0.5 ± 0.2 to 0.5 ± 0.2 pg·ml−1). At the end of immersion, basic affect was lowest for HWI (HWI: − 1.8 ± 2.0, FAN: 0.2 ± 1.6, CON 1.0 ± 2.1, P < 0.02); thermal comfort for HWI was in the uncomfortable range (3.0 ± 1.0, P < 0.01 when compared with FAN and CON), whereas FAN (0.7 ± 0.7) and CON (-0.2 ± 0.7) were in the comfortable range. Conclusion Local cooling of the upper body during hot water immersion improves basic affect and thermal comfort without inhibiting the acute IL-6 response.

Hemodynamics of post-exercise vs. post hot water immersion recovery

This study sought to compare the hemodynamics of the recovery periods following exercise versus hot water immersion. Twelve subjects (6 F, 22.7 ± 0.8 y; BMI: 21.8 ± 2.1 kg·m-2) exercised for 60 minutes at 60% VO2peak or were immersed in 40.5oC water for 60 minutes on separate days, in random order. Measurements were made before, during, and for 60-minutes post-intervention (i.e., recovery) and included heart rate, arterial pressure, core temperature, and subjective measures. Brachial and superficial femoral artery blood flows were assessed using Doppler ultrasonography and cardiac output was measured using the acetylene wash-in method. Internal temperature increased to a similar extent during exercise and hot water immersion. Cardiac output and mean arterial pressure were greater during exercise than during hot water immersion (both p<0.01). Sustained reductions in mean arterial pressure compared to baseline were observed in both conditions during recovery (p<0.001 vs before each intervention). Cardiac output was similar during recovery between the interventions. Stroke volume was reduced throughout recovery following exercise, but not following hot water immersion (p<0.01). Brachial artery retrograde shear was reduced following hot water immersion, but not following exercise (Interaction; p=0.035). Antegrade shear in the superficial femoral artery was elevated compared to baseline (p=0.027) for 60 minutes following exercise, whereas it returned near baseline values (p=0.564) by 40 minutes following hot water immersion. Many of the changes observed during the post-exercise recovery period that are thought to contribute to long-term beneficial cardiovascular adaptations were also observed during the post-hot water immersion recovery period.