scholarly journals The Effect of Medium-Term Sauna-Based Heat Acclimation (MPHA) on Thermophysiological and Plasma Volume Responses to Exercise Performed under Temperate Conditions in Elite Cross-Country Skiers

2021 ◽  
Vol 18 (13) ◽  
pp. 6906
Author(s):  
Ilona Pokora ◽  
Ewa Sadowska-Krępa ◽  
Łukasz Wolowski ◽  
Piotr Wyderka ◽  
Anna Michnik ◽  
...  
Keyword(s):  
Plasma Volume ◽  
Exercise Test ◽  
Physiological Strain ◽  
Hematological Indices ◽  
Physiological Variables ◽  
Before And After ◽  
Exercise Effect ◽  
Cross Country ◽  
Response To Exercise ◽  
Weak Influence

The influence of a series of ten sauna baths (MPHA) on thermophysiological and selected hematological responses in 14 elite cross-country skiers to a submaximal endurance exercise test performed under thermoneutral environmental conditions was studied. Thermal and physiological variables were measured before and after the exercise test, whereas selected hematological indices were studied before, immediately after, and during recovery after a run, before (T1) and after sauna baths (T2). MPHA did not influence the baseline internal, body, and skin temperatures. There was a decrease in the resting heart rate (HR: p = 0.001) and physiological strain (PSI: p = 0.052) after MPHA and a significant effect of MPHA on systolic blood pressure (p = 0.03), hematological indices, and an exercise effect but no combined effect of treatments and exercise on the tested variables. A positive correlation was reported between PSI and total protein (%ΔTP) in T2 and a negative between plasma volume (%ΔPV) and mean red cellular volume (%ΔMCV) in T1 and T2 in response to exercise and a positive one during recovery. This may suggest that MPHA has a weak influence on body temperatures but causes a moderate decrease in PSI and modifications of plasma volume restoration in response to exercise under temperate conditions in elite athletes.

scholarly journals Do exist gender differences in skin temperature of lower limbs following exercise test in male and female cross-country skiers?

2021 ◽  
Author(s):  
M. Binek ◽  
Z. Drzazga ◽  
T. Socha ◽  
I. Pokora
Keyword(s):  
Skin Temperature ◽  
Exercise Test ◽  
Physiological Parameters ◽  
Lower Limbs ◽  
Metabolic Energy ◽  
Men And Women ◽  
Male And Female ◽  
Significant Difference ◽  
Cross Country ◽  
Response To Exercise

AbstractThe aim of study was to assess the skin temperature changes over selected muscles zones of the lower limbs following an exercise performed at similar relative external workload in 10 male and 6 female high-trained cross-country skiers. The first stage of experiment involved preliminary exercise to determine individual oxygen uptake VO2max and anaerobic threshold. The second stage experimental exercise consisted of 60 min running on treadmill with 80% of determined VO2max Thermographic imaging of lower limbs was performed, before, immediately after exercise and during recovery. Physiological parameters: VO2, MET—metabolic energy equivalent, heart rate and internal temperature were assessed at rest and at the end of exercise, respectively. Infrared thermography showed that at rest the skin temperature over lower limb muscles was significantly higher in men than in women. In response to exercise an increase in skin temperature over the studied muscles was significantly higher in women than men. Since was no significant difference in skin temperature in men and women after exercise. Before the test, no physiological parameter was significantly different in women and men. Exercise test reveled significant differences between men and women in some physiological parameters such as VO2 and MET. Our study showed that there are significant differences in lower limbs skin temperature between male and female at rest but not at the end of exercise test. Women in comparison with men had a greater increase in skin temperature in response to exercise and a persistence of elevated temperature over muscles of lower limbs after exercise.

Muscle triglyceride utilization during exercise: effect of training

1986 ◽  
Vol 60 (2) ◽  
pp. 562-567 ◽  
Author(s):  
B. F. Hurley ◽  
P. M. Nemeth ◽  
W. H. Martin ◽  
J. M. Hagberg ◽  
G. P. Dalsky ◽  
...  
Keyword(s):  
Exercise Test ◽  
Respiratory Exchange Ratio ◽  
Absolute Intensity ◽  
Quadriceps Muscle ◽  
Before And After ◽  
Exercise Effect ◽  
Plasma Ffa ◽  
Glycogen Utilization ◽  
Male Subjects ◽  
Muscle Triglyceride

The respiratory exchange ratio (RER) is lower during exercise of the same intensity in the trained compared with the untrained state, even though plasma free fatty acids (FFA) and glycerol levels are lower, suggesting reduced availability of plasma FFA. In this context, we evaluated the possibility that lipolysis of muscle triglycerides might be higher in the trained state. Nine adult male subjects performed a prolonged bout of exercise of the same absolute intensity before and after adapting to a strenuous 12-wk program of endurance exercise. The exercise test required 64% of maximum O2 uptake before training. Plasma FFA and glycerol concentrations and RER during the exercise test were lower in the trained than in the untrained state. The proportion of the caloric expenditure derived from fat, calculated from the RER, during the exercise test increased from 35% before training to 57% after training. Muscle glycogen utilization was 41% lower, whereas the decrease in quadriceps muscle triglyceride concentration was roughly twice as great (12.7 +/- 5.5 vs. 26.1 +/- 9.3 mmol/kg dry wt, P less than 0.001) in the trained state. These results suggest that the greater utilization of FFA in the trained state is fueled by increased lipolysis of muscle triglyceride.

Biathlon Performance: Heart Rate, Hit Rate, Speed and Physiological Variables

2021 ◽  
Vol 15 (10) ◽  
pp. 3245-3249
Author(s):  
Gökhan Atasever ◽  
Fatih Kiyici ◽  
Deniz Bedir ◽  
Fatih Ağduman
Keyword(s):  
Heart Rate ◽  
Lean Body Mass ◽  
Body Mass ◽  
Body Fat ◽  
Maximum Speed ◽  
Fat Percentage ◽  
Physiological Variables ◽  
Cross Country Skiing ◽  
Cross Country ◽  
Short Time

Aim: Biathlon is a sport that combines cross-country skiing and rifle shooting. The athlete is fast in the cross-country skiing section, in the gun shooting section, the heart rate should be low. This study aims to determine the hitting rate of the shots made with different training loads on low altitude in elite biathletes in terms of maximum speed and physiological variables. Methods: To evaluate shooting performances first with the resting pulse and then after 2.5 km skiing respectively with 50%, 70% and 100% pulse rate which is separately calculated for each athlete according to karvonen formula. Results: Our findings show that while there was negative relation between maximum speed and body fat there was a positive relation with lean body mass. It has been determined that low body fat percentage and high lean body mass are effective at the athletes’ maximum speed and the pulse level with the highest target shooting accuracy rate was at rest and 70% in the second level. Conclusion: Since the pulse of the athlete who comes to the shooting area cannot be reduced to a resting level in a short time, focusing the 70% pulse zone may be beneficial in terms of shooting accuracy and acceleration after the shot. The lowest results in target shooting accuracy were seen at 50% and 100% loads. Keywords: Athletes, performance, heart, rate, lean body mass.

EFFECTS OF RUNNING AND CROSS-COUNTRY SKIING ON CARIORESPIRATORY RESPONSE TO EXERCISE

1985 ◽  
Vol 17 (2) ◽  
pp. 270
Author(s):  
P. Oja ◽  
I. Vuori ◽  
R. Nieminen ◽  
K. Kukkonen-Harjula ◽  
S. Niittymäki
Keyword(s):  
Cross Country Skiing ◽  
Cross Country ◽  
Response To Exercise

scholarly journals Comparative methodological studies of L-asparaginase encapsulation into erythrocytes

2018 ◽  
Vol 13 (3) ◽  
pp. 91-101
Author(s):  
D. V. Borsakova ◽  
M. E. Plakhotnik ◽  
L. D. Koleva ◽  
E. A. Bovt ◽  
Yu. G. Alexandrovich ◽  
...  
Keyword(s):  
Lymphoblastic Leukemia ◽  
Comparative Investigation ◽  
Hypertonic Solution ◽  
Clinical Use ◽  
Hematological Indices ◽  
Healthy Donors ◽  
Wide Range ◽  
Before And After ◽  
Hypotonic Buffer ◽  
Flow Dialysis

Background. L-asparaginase is an enzyme, widely used in the therapy of acute lymphoblastic leukemia in children and adults, but its use is limited due to a wide range of side effects and anaphylactic reactions. L-asparaginase loaded into erythrocytes can solve these problems. This enzyme is protected from the immune system and plasma proteases due to erythrocyte membrane, but continues to work inside the cell because its membrane is permeable to L-asparagine. Thus, the half-life of the drug increases and anaphylactic reactions reduce. The encapsulation of L-asparaginase into erythrocytes can be performed by various osmotic methods. Each of them is characterized by the amount of encapsulated enzyme, the cell yield, as well as by the quality indices of the survived erythrocytes. An important parameter of each method is the possibility to provide sterility of this dosage form for the clinical use.The aim of the study was the comparing of three osmotic methods of L-asparaginase encapsulation into erythrocytes (hypo-osmotic lysis, dialysis and flow dialysis) to select the most promising method for clinical use.Materials and methods. A suspension of erythrocytes of healthy donors (hematocrit 60–70%) was mixed with L-asparaginase from E. сoli. The procedures of hypotonic reversible lysis, dialysis in dialysis bags, or flow dialysis using pediatric dialyzers were performed. The physiological osmolality was restored in suspensions after the procedure by the addition of a hypertonic solution, and they were incubated for 30 min at 37 °C. Then the cells were washed in isotonic phosphate-buffered saline with pH 7.4. Activity of L-asparaginase, volume, hematocrit, hematological indices and osmotic cell fragility of erythrocytes were measured in the suspensions of erythrocytes before and after the enzyme encapsulation procedure.Results. An optimal osmolality of the hypotonic buffer for each method was selected and was equal to 90–110 mOsm/kg. The yields of encapsulation were 4.2 ± 2.0, 6.0 ± 2.3 and 16.2 ± 2.2 % for hypotonic lysis, dialysis and flow dialysis, respectively. The hematological indices of the obtained erythrocyte-carriers differed from the corresponding parameters of the initial erythrocytes, but did not differ significantly for different methods.Conclusion. Comparative investigation of mentioned above parameters allowed choosing the method of flow dialysis as the most promising for clinical use.

Hemodynamic effects of normovolemic polycythemia in dogs at rest and during exercise

1964 ◽  
Vol 207 (6) ◽  
pp. 1361-1366 ◽  
Author(s):  
Allen B. Weisse ◽  
Farrell M. Calton ◽  
Hiroshi Kuida ◽  
Hans H. Hecht
Keyword(s):  
Cardiac Output ◽  
Pulmonary Artery ◽  
Oxygen Transport ◽  
Peripheral Resistance ◽  
Relative Increase ◽  
Red Cells ◽  
Hemodynamic Effects ◽  
Venous Oxygen Saturation ◽  
Before And After ◽  
Response To Exercise

The hemodynamic effects of acutely induced normovolemic polycythemia were studied in four anesthetized and seven unanesthetized dogs at rest and, in three of the latter, during treadmill exercise. Control observations were made in four other animals. Volume of packed red cells values of 60–79% were produced by exchange transfusion with washed centrifuged red cells. Normovolemic polycythemia in both anesthetized and unanesthetized resting animals was associated with a decrease in cardiac output and oxygen transport; little change in pulmonary artery, carotid artery, right atrium, and pulmonary artery wedge pressures; and increases in calculated total systemic and pulmonary vascular resistances. Mixed venous oxygen saturation was not necessarily reduced. The relative increase in cardiac output and oxygen transport in response to exercise was similar before and after normovolemic polycythemia, but the absolute increments were significantly less after normovolemic polycythemia. Results obtained are consistent with the concept that cardiac output reduction with normovolemic polycythemia is mediated by increased peripheral resistance.

Predominant site of flow limitation and mechanisms of postexertional asthma

1977 ◽  
Vol 42 (5) ◽  
pp. 746-752 ◽  
Author(s):  
E. R. McFadden ◽  
R. H. Ingram ◽  
R. L. Haynes ◽  
J. J. Wellman
Keyword(s):  
Airway Obstruction ◽  
Physical Exertion ◽  
Anticholinergic Agent ◽  
Disodium Cromoglycate ◽  
Flow Limitation ◽  
Before And After ◽  
Large Airways ◽  
Airway Response ◽  
Exercise Induced ◽  
Response To Exercise

To determine if a relationship existed between the site of airway obstruction and the mechanisms of exercise-induced asthma, we studied the predominant site of flow limitation, as determined by the mid-vital capacity ratios of maximal expiratory flow with air (Vmax air) and 80% helium-20% oxygen (Vmax He-O2), before and after physical exertion in 12 asthmatics. These observations were then related to the effects seen after vagal blockade and inhibition of mediator release. Five subjects increased Vmax He-O2/Vmax air ratios suggesting that the predominant site of flow limitation was in large airways. This group had their postexercise bronchospasm abolished by pretreatment with an anticholinergic agent. Seven subjects decreased their flow ratios indicating predominant small airway obstruction. Anticholinergic agents, although producing bronchodilation, did not alter their bronchospastic response to exercise. However, pretreatment with disodium cromoglycate did significantly diminish the response of this group. Thus the airway response to exercise in asthmatics is heterogeneous in terms of predominant site of flow limitation and this factor appears to relate to mechanisms.

scholarly journals Audit committee quality and audit report lag: the role of mandatory adoption of IFRS in Saudi companies

Accounting ◽  
2021 ◽  
pp. 167-178
Author(s):  
Mahfod Mobarak Aldoseri ◽  
Nasr Taha Hassan ◽  
Magdy Melegy Abd El Hakim Melegy
Keyword(s):  
Financial Reporting ◽  
Audit Committee ◽  
Audit Committees ◽  
Strong Impact ◽  
Audit Report ◽  
Before And After ◽  
Mandatory Adoption ◽  
The Impact ◽  
Weak Influence

This paper aims to examine the effect of audit committee characteristics on audit report lag, and also explores whether this effect will vary between before and after mandatory adoption of IFRS in Saudi listed companies. Based on a Saudi sample of 388 firm-year observations from 2015 to 2018, the Poisson regression analysis shows that among audit committee characteristics, only audit committee financial experience significantly influences the timing of financial reporting. The result indicates a weak influence of audit committees on timeliness of financial reporting, which is consistent with the results of most of previous studies. On the other hand, the results show a strong impact of the adoption of IFRS on the context of that relationship, where the results show the impact of IFRS on audit report lag, audit committee quality and the association between them.

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