title: Heart adaptation to physical exertion in relation to work duration.
mesh_terms: D000136:Acid-Base Equilibrium; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D003345:Corticosterone / Q000097:blood; D004562:Electrocardiography; D006321:Heart / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism*; D005082:Physical Exertion; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D013550:Swimming; D013997:Time Factors; D014882:Water-Electrolyte Balance
chemical_list: D012964:Sodium; D000251:Adenosine Triphosphatases; D011188:Potassium; D003345:Corticosterone