Flávia Yázigi presents

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1 Flávia Yázigi presents

2 CONCEPTS Heart rate: The number of heart beats per unit time, usually per minute. is based on the number of contractions of the ventricles (the lower chambers of the heart). may be too fast (tachycardia) or too slow (bradycardia). The pulse is bulge of an artery from the wave of blood coursing through the blood vessel as a result of the heart beat. The pulse is often taken at the wrist or at neck to estimate the heart rate.

3 Maximun Heart Rate Definition: The highest number of times a walker's heart can beat in a minute of exercising. is a genetically determined "random" variable; it has no bearing on a walker's current fitness or potential as an athlete. To determine your max HR, subtract your age from 220(ACSM 2005)

4 Resting Heart Rate Definition: The number of times a walker's heart beats per minute while at complete rest. Resting heart rate will decrease as the walker's heart becomes larger and stronger with training. A low resting heart rate is an indicator of fitness The units are bpm = beats per minute. Your resting heart rate should be taken first thing in the morning, before getting out of bed. Take your pulse for 60 seconds.

5 Hemodynamics Hemodynamics is an important part of cardiovascular physiology dealing with the forces the pump (the heart) has to develop to circulate blood through the cardiovascular system Cardiovascular health adequate supply of oxygen to all tissues

6 Hemodynamics systemic hemodynamics - the blood pressure and blood flow at the output of the left heart Hypertension and congestive heart failure are two best known systemic hemodynamic disorders. the cardiovascular system actually forms a new hemodynamic state for every heart beat.

7 Hemodynamic Modulators Three hemodynamic modulators are the causes of changes of levels of blood pressure (MAP = Mean Arterial Pressure) and blood flow (SI = Stroke Index). These modulators are: intravascular volume inotropy vasoactivity Subsequently, the fourth modulator chronotropy

8 Intravascular volume about 20% of our blood is within the arterial system, while the remaining 80% is within the venous system About 10% of our weight is blood Inhale: create a negative pressure within our thorax. inrush of air into our lungs through nose and mouth and for an increase of venous blood return toward the heart. This increased venous return will momentarily move our hemodynamic point northeast. Exhale: a positive intrathoracic pressure will expel the air from the lungs will diminish our venous return and move the hemodynamic point momentarily southwest

9 Inotropes Hormone-like substances, which circulate within the blood. When they reach the receptors in the heart, they control and affect the rate of contraction of the heart fibers in time. Positive inotropes increase the rate of contraction of myocardial fibers (they contract more vigorously in a shorter time), the heart expels more blood, and the values of SI and MAP increase. Negative inotropes have the opposite effect and, as a result of their presence, the SI and MAP values decrease

10 Vasoactivity Controls the flow of blood through individual organs Vasodilatation is used to increase blood flow through an organ when its oxygen demand increases. Regional vasoconstriction is applied to reduce blood flow through an organ

11 Cardiac Index (CI) Is the perfusion flow CI = SI (Stroke Index; blood flow) X HR (Heart Rate) In a healthy patient, between the rest (the lowest oxygen demand) and a strenuous exercise, such as running a marathon (the highest oxygen demand), the SI increases by 66%, CI by 500%, while MAP changes a little or not at all

12 Cardiac Index (CI) A different set of MAP & SI values represents an ideal normohemodynamic state for different ages, genders and metabolic states

13 Immersion and Heart Rate OLD AEA GUIDELINES Factors: temperature, gravity, compression, Partial pressure; dive reflex HR Target Zone to aerobic workout in aquatic exercise: Must reduce 17 BPM (13%) from the minimum and maximun land training thresholds

14 (Arborelius, Balldin, Lilja, & Lundgren, 1972) Hydrostatic effects of water cause a shift of blood volume from the periphery of the body to the thorax. This increases the central venous pressure, stroke volume and cardiac output, which leads to a decrease in heart rate

15 Immersion and Heart Rate Heart rate response in water depends considerably on water temperature (Avellini, Shapiro, & Pandolf, 1983) The combined influence of water temperature and hydrostatic pressure help to explain why, at a given VO2, heart rate has been shown to be up to 20 bpm lower in water than on land (Mougios & Deligiannis, 1993).

16 (Craig & Dvorak, 1969) Head-out, underwater exercise at 25&Mac251;C (77 F) has been shown to produce a lower heart rate response than land, at a set oxygen consumption. Increasing the water temperature to 30-35C (86-95 F) shows little difference from land-based heart rate response

17 Effects of water depth on abdominal [correction of abdominails] aorta and inferior vena cava during standing in water Onodera, S., Miyachi, M., Nishimura, M., Yamamoto, K., Yamaguchi, H., Takahashi, K., et al. (2001).. J Gravit Physiol, 8(1), P During water immersion bradycardia and increase in stroke volume induce by changing in hydrostatic pressure. We hypothesised that the cardiac alterations with immersion are associates with an increase in venous return from lower body

18 Hemodynamic response to graded water immersion Lollgen H, von Nieding G, Koppenhagen K, Kersting F, Just H (1981).. Klin Wochenschr Jun 15;59(12): Healthy male subjects in a thermoneutral bath in the sitting position Heart rate decreased from rest to hip immersion but remained constant from hip to head out water immersion. Plasma norepinephrine concentration remained constant throughout the experiment.

19 Hemodynamic Changes in Water Immersion: Evaluation of Flow Velocity Pattern by Pulsed Doppler Untrasound Hiroshi Igarashi, Hirohiko Shiraishi, Yutaka Kikuchi, Kou Ichihashi, and Masayoshi YanagisawaDepartment of Pediatrics, Hichi Medical School Pediatric Cardiology and Cardiac Surgery Vol.9 No ( ) 26 C in the standing position heart rate decreased but blood pressure did not change Increase peak of velocity of the right ventricular inflow

20 NEW AEA guidelines Exercise Intensity at 50% : Lower 5-10 bpm Exercise Intensity at 85% and Deep Water: Lower bpm Needs more researches HR CONTROL Borg scale (rating perceived exertion) Talk test

21 (Frangolias,2000) HR responses to exercise at and at WI were similar during short-term exercise, but values tended to be lower during prolonged exercise in the WI condition.

22 (Nishimura, 2000) It is known that heart rate, oxygen uptake and body temperature during exercise in water are affected by water temperature, buoyancy and so on. Relaxation in water (supine floating) has been performed in hydrotherapy and aqua exercise. But there were few reports about supine floating (Schulz and Kaspar 1994).

23 (Dowzer, 1999) VO2 peak averaged 83.7 and 75.3% of VO2 max for SWR and DWR respectively. Peak HR for SWR and DWR were 94.1 and 87.2% of the HRmax reached in the TMR(Treadmill Running).

24 BLOOD PRESSURE results showed BP to decrease significantly on entering the water (MAP mean difference of mm Hg, 95% CI 8.75 to 12.29), to remain at this low level postexercise while still immersed, and then return to preimmersion values 8-12 minutes after exiting the water. (Ward, 2005)

25 MAIN FACTORS TEMPERATURE BUOYANCY The heart rate response to water exercise is based primarily on the depth of the water, water temperature and intensity of the workout (Kravitz, 1997)

26 CONCLUSION WE CONCLUDE THAT MORE RESEARCHES ARE NECESSARY, WITH THE SAME TEMPERATURE AND DEPH CONDITIONS