Delayed Rebound of Glycemia During Recovery Following Short-Duration High-Intensity Exercise: Are There Lactate and Glucose Metabolism Interactions?

Lactate constitutes the primary gluconeogenic precursor in healthy humans at rest and during low-intensity exercise. Data on the interactions between lactate and glucose metabolisms during recovery after short-duration high-intensity exercise are sparse. The aim of the present study was to describe blood glucose ([glucose]b) and lactate ([lactate]b) concentration curves during recovery following short-duration high-intensity exercise. Fifteen healthy Cameroonian subjects took part in the study and performed successively (i) an incremental exercise to exhaustion to determine maximal work rate (Pmax) and (ii) a 2-min 110% Pmax exercise after which blood lactate and glucose concentrations were measured during the 80-min passive recovery. In response to the 2-min 110% Pmax exercise, [glucose]b remained stable (from 4.93 ± 1.13 to 4.65 ± 0.74 mmol.L−1, NS) while [lactate]b increased (from 1.35 ± 0.36 to 7.87 ± 1.66 mmol.L−1, p < 0.0001). During recovery, blood lactate concentrations displayed the classic biphasic curve while blood glucose concentrations displayed a singular shape including a delayed and transitory rebound of glycemia. This rebound began at 27.7 ± 6.2 min and peaked at 6.78 ± 0.53 mmol.L−1 at 56.3 ± 9.7 min into recovery. The area under the curve (AUC) of [lactate]b during the rebound of glycemia was positively correlated with the peak value of glycemia and the AUC of [glucose]b during the rebound. In conclusion, the delayed rebound of glycemia observed in the present study was associated with lactate availability during this period.

THE BIDIRECTIONAL EFFECT OF CREATINE SUPPORTS THE MAINTENANCE OF OXIDANT-ANTIOXIDANT HOMEOSTASIS DURING EXERCISE

The importance of supplements used with exercise is increasing day by day. In this study, it was aimed to evaluate the effects of creatine monohydrate (CrM) supplementation with different intensities of exercise on oxidative stress through dynamic thiol disulfide homeostasis. Fourty two BALB/c mice were used and randomly divided into 6 groups; control (C), low-intensity exercise (LIE), high-intensity exercise (HIE), C+CrM (4% of daily diet), LIE+CrM, and HIE+CrM groups. Exercise groups were performed low-intensity (8m/min/30min/day) and high-intensity (24m/min/30min/day) exercise on a mouse treadmill for 8 weeks. At the end of the experimental period, the thiol disulfide homeostasis levels analyzed by using a new automated measurement technique. When the native thiol and total thiol values were examined the difference between the groups was statistically significant (respectively, p=0.029, p=0,035). Creatine intake with exercise decreased native thiol and total thiol levels. However, serum disulfide levels were lower in LIE+CrM compared to other study groups, but there was no statistically significant difference. It is thought that creatine supplementation with exercise reduces the thiol-disulfide homeostasis burden of the organism, and that after the depletion of creatine stores, the sustainability of oxidant-antioxidant homeostasis can be extended, thus prolonging the duration of antioxidant resistance.

Appropriate exercise level attenuates gut dysbiosis and valeric acid increase to improve neuroplasticity and cognitive function after surgery in mice

Postoperative cognitive dysfunction (POCD) affects the outcome of millions of patients each year. Aging is a risk factor for POCD. Here, we showed that surgery induced learning and memory dysfunction in adult mice. Transplantation of feces from surgery mice but not from control mice led to learning and memory impairment in non-surgery mice. Low intensity exercise improved learning and memory in surgery mice. Exercise attenuated surgery-induced neuroinflammation and decrease of gut microbiota diversity. These exercise effects were present in non-exercise mice receiving feces from exercise mice. Exercise reduced valeric acid, a gut microbiota product, in the blood. Valeric acid worsened neuroinflammation, learning and memory in exercise mice with surgery. The downstream effects of exercise included attenuating growth factor decrease, maintaining astrocytes in the A2 phenotypical form possibly via decreasing C3 signaling and improving neuroplasticity. Similar to these results from adult mice, exercise attenuated learning and memory impairment in old mice with surgery. Old mice receiving feces from old exercise mice had better learning and memory than those receiving control old mouse feces. Surgery increased blood valeric acid. Valeric acid blocked exercise effects on learning and memory in old surgery mice. Exercise stabilized gut microbiota, reduced neuroinflammation, attenuated growth factor decrease and preserved neuroplasticity in old mice with surgery. These results provide direct evidence that gut microbiota alteration contributes to POCD development. Valeric acid is a mediator for this effect and a potential target for brain health. Low intensity exercise stabilizes gut microbiota in the presence of insult, such as surgery.

Impact of Low Intensity Exercise on Liver Enzymes (ALT & ALP)

This particular research study was basically carried out for the purpose to examine the impact of low intensity exercise on two particular liver enzymes i.e. alanine transaminase (ALT) and alkaline phosphate (ALP). 20 Non sportsmen were selected as subjects of the study (n=20, age 20 to 30 years (20.95±3.79), Body Mass Index (BMI) from 18 to 30 (25.90±5.54). Similarly the subjects were divided into two groups (Experimental Group and Control Group) through the application of International Physical Activity Questionnaire (IPAQ) and measurement of Maximum Heart Rate (MHR). 12 weeks self-made low intensity exercise protocol was applied to an experimental group. 5ml blood was collected from all subjects to measure the effect of low intensity exercise on ALT and ALP. The data of pre and post-test were processed through SPSS version 24. Based on analysis and findings, the researcher concluded that in experimental group (EXG) the level of ALT and ALP was found significantly higher (p<0.05) as compared to control group (CG). Based on conclusion, it is hereby recommended by the researcher that for the purpose to promote the functional capacity of liver, low as well as moderate intensity exercise should be performed on daily basis. In addition, in this study due to lack of financial resources, two basic liver enzymes i.e.ALT and ALP were measured, therefore the other enzymes like as AST and bilirubin also need to be examined in such other research studies.

Physical activities of jockeys during a working week

Horse racing and training is a physically demanding sport. The aims of this study were to quantify the physical activities of jockeys during a working week and to investigate self-reported fall and injury incidence rates of jockeys at work. A daily workload diary examining workday and physical activities was emailed to all jockeys licensed to ride in a race in New Zealand in 2020. Sixty-three jockeys (25 apprentices, 33 professional and 5 amateur riders) began the diary, representing 38% of the licensed population of jockeys in New Zealand. Jockeys worked a median of 44 (interquartile range (IQR) 33-57) hours, 6-days per week. A median of 7 (IQR 6-9) horses were ridden per day, comprising 58% of work time, with 11 (IQR 7-15) hours per week spent at training pace. Elite jockeys (high performance in the premiership table) spent more time riding in races (1.1, IQR 0.7-1.2 hours per week) than non-elite jockeys (0.0, 0.0-0.4, P=0.01), with 29% (IQR 0-54%) of their weekly rides as race rides. Extra physical training was conducted by 72% of jockeys, which consisted mainly of low intensity exercise such as pleasure riding (56%) and walking (43%). Falls during morning exercise work were recorded by 87% of respondents, 40% of which had sustained an injury in the previous 12 months. Jockeys who participated in extra physical training had higher fall incidence rates per 1000 horses ridden in morning exercise work (3.5, 95% confidence interval (CI) 3.1-3.9, P=0.002) but lower fall incidence rate in race riding (2.1, 95% CI 1.5-2.8, P<0.001) than jockeys who did no extra training (2.5, 95% CI 2.0-3.0 and 5.9, 95% CI 3.8-9.0). Elite jockeys experience a level of specific race exercise which is lacking in the other jockeys.

The Effect of Low and Moderate Exercise on Hyperuricemia: Protocol for a Randomized Controlled Study

BackgroundHyperuricemia (HUA) is a metabolic disease by purine metabolism disorders. It is a risk factor for many chronic diseases, including diabetes, hypertension, and heart disease. Studies have shown that exercise can effectively reduce serum uric acid (SUA), but the optimal exercise dose, intensity, and mode of exercise for improving HUA have not been verified in clinical studies. Therefore, this study aims to explore the effect of different exercise intensities in improving SUA of patients with HUA.Methods and AnalysisA randomized, single-blind, parallel controlled trial will be conducted in this study. 186 HUA patients who meet the inclusion criteria will be randomly divided into a 1:1:1 ratio (1): control group (2), low-intensity exercise group (brisk walking, 57-63% maximum heart rate, 150 min/week, 12 months), and (3) moderate-intensity exercise group (jogging, 64-76% maximum heart rate, 150 min/week, 12 months). The three groups of subjects will receive the same health education and prohibition of high-purine diet during the intervention period. The primary outcomes will be SUA concentration, SUA concentration change (mg/dL), SUA change rate (%), and the proportion of HUA patients. Secondary outcomes will include anthropometric parameters (body weight, waist circumference, hip circumference, BMI); physiological indicators (blood pressure, grip, vital capacity, maximum oxygen); biochemical indicators (blood lipid, blood sugar, liver enzyme, creatinine, and blood urea nitrogen). Each group of patients will go through an assessment at baseline, 3rd, 6th, and 12th months.DiscussionThis study will evaluate the effect of 12-month low-intensity exercise and moderate-intensity exercise on HUA patients. We hypothesize that both low-intensity and moderate-intensity exercise would improve HUA as compared with no-exercise control, and that moderate-intensity exercise would be more effective than low-intensity exercise in improving HUA. These results can provide a basis for the current physical activity guidelines for HUA’s healthy lifestyle management.Ethics and DisseminationThis study has been approved by the Ethical Review Committee of the Shanghai University of Sport (approval number: 102772020RT005). Informed consent will be obtained from all participants or their guardians. The authors intend to submit the study findings to peer-reviewed journals or academic conferences to be published.Clinical Trial RegistrationChinese Clinical Trial Registry, identifier ChiCTR2100042643.