{"id":2176,"date":"2018-11-13T19:40:49","date_gmt":"2018-11-13T19:40:49","guid":{"rendered":"https:\/\/medicalcriteria.com\/web\/?p=1364"},"modified":"2026-02-10T19:21:11","modified_gmt":"2026-02-10T19:21:11","slug":"training","status":"publish","type":"post","link":"https:\/\/medicalcriteria.com\/web\/training\/","title":{"rendered":"Chronic Adaptations to Physical Training (PT)"},"content":{"rendered":"<div class=\"99c380e4b4a7b96c35d7ddf7dcb434e8\" data-index=\"1\" style=\"float: none; margin:0px 0 0px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<!-- MC 2019- Horizontal -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-client=\"ca-pub-0127150553352455\"\r\n     data-ad-slot=\"3806776041\"\r\n     data-ad-format=\"auto\"\r\n     data-full-width-responsive=\"true\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n<p>Long-term responses that develop over a period of time (usually a minimum of 6 weeks)\u00a0when training is repeated regularly are referred to as chronic adaptations to training. The\u00a0combined effect of all chronic adaptations is known as the training effect.<br \/>\nChronic adaptations to training may occur in the cardiovascular, respiratory and muscular\u00a0systems. The result of these physiological adaptations is an improvement in performance.<!--more--><\/p>\n<p>Chronic adaptations to training vary greatly and are dependent upon\u00a0the type and method of training undertaken, whether it be aerobic, anaerobic\u00a0or resistance training<\/p>\n<p><strong>Chronic <em>aerobic<\/em> adaptations to training<\/strong><\/p>\n<p>Cardiovascular<\/p>\n<ul>\n<li>Increased left ventricle size and\u00a0volume (increased stroke volume):\u00a0Aerobic training results in cardiac hypertrophy. An increase in the size and volume of the left\u00a0ventricle, in particular, occurs. This increases stroke volume and cardiac output, allowing\u00a0a greater volume of blood to be ejected from the heart, thus providing more oxygen for the\u00a0athlete to use.<\/li>\n<li>Increased capillarisation of the\u00a0heart muscle:\u00a0Cardiac hypertrophy also leads to an increase in the capillarisation of the heart muscle itself.\u00a0The increased supply of blood and oxygen allows the heart to beat more strongly and efficiently\u00a0during both exercise and rest.<\/li>\n<li>Faster heart rate recovery rates increased heart rate recovery rates mean that the heart rate will return to resting levels in a much shorter time than that of an untrained individual. This is due to the greater efficiency of the cardiovascular system to produce energy aerobically.<\/li>\n<li>Increased blood volume and\u00a0haemoglobin levels:\u00a0Red blood cells may increase in number and the haemoglobin content and oxygen-carrying\u00a0capacity of the blood may also rise. There is also an increased ratio of plasma in the blood\u00a0cells, which reduces the viscosity of the blood allowing it to flow smoothly through the blood\u00a0vessels. This allows a greater amount of oxygen to be delivered to the muscles and used by the\u00a0athlete.<\/li>\n<li>Increased capillarisation of\u00a0skeletal muscle:\u00a0Aerobic training leads to increased capillarisation of skeletal muscle. Greater capillary supply\u00a0means increased blood flow and greater surface area for gas diffusion to take place. Increasing\u00a0the oxygen and nutrients into the muscles allows for more removal of by-products<\/li>\n<li>Decreased heart rate at rest and\u00a0during submaximal workloads:\u00a0A greater stroke volume results in the heart not having to beat as often to supply the required\u00a0blood flow (and oxygen). Aerobic training also results in a slower increase in heart rate during\u00a0exercise and also a lower steady state that is reached sooner.<\/li>\n<\/ul>\n<p>Respiratory<\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li>Increased alveolar surface area\u00a0(increased pulmonary diffusion):\u00a0Aerobic training increases the surface area of the alveoli, which in turn increases the pulmonary diffusion, allowing more oxygen to be extracted and transported to the working muscles for use.<\/li>\n<li>Increased tidal volume: Aerobic training increases the amount of air inspired and expired by the lungs per breath. This\u00a0allows for a greater amount of oxygen to be diffused into the surrounding alveoli capillaries and\u00a0delivered to the working muscles.<\/li>\n<li>Increased ventilation during\u00a0maximal exercise:\u00a0Aerobic training results in more efficient lung ventilation. Ventilation may be reduced slightly\u00a0at rest and during submaximal exercise due to improved oxygen utilisation. At maximal\u00a0workloads, ventilation is increased due to an increase in tidal volume and respiratory frequency.\u00a0This allows for greater oxygen delivery to working muscles at maximum exercise intensities.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script><br \/>\n<ins class=\"adsbygoogle\" style=\"display: block; text-align: center;\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\" data-ad-client=\"ca-pub-0127150553352455\" data-ad-slot=\"7834404329\"><\/ins><br \/>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><\/p>\n<p>Muscular<\/p>\n<ul>\n<li>Increased size and number of\u00a0mitochondria:\u00a0Mitochondria are the sites of aerobic ATP resynthesis and where glycogen and triglyceride\u00a0stores are oxidised. The greater the number and size of the mitochondria located within the\u00a0muscle, the greater the ability to resynthesise ATP aerobically.<\/li>\n<li>Increased myoglobin stores: Myoglobin is responsible for extracting oxygen from the red blood cells and delivering it to the\u00a0mitochondria in the muscle cell. An increase in the number of myoglobin stores increases the\u00a0amount of oxygen delivered to the mitochondria for energy production.<\/li>\n<li>Increased fuel storage and\u00a0oxidative enzymes:\u00a0Aerobic training increases the muscular storage of glycogen and triglycerides in the slowtwitch\u00a0muscle fibres and there is also an increase in the oxidative enzymes that are responsible\u00a0for metabolising these fuel stores to produce ATP aerobically. This means that there is less\u00a0reliance upon the anaerobic glycolysis system until higher intensities. In addition to this, due to\u00a0increased levels of the enzymes associated with fat metabolism, an aerobically trained athlete is\u00a0able to \u2018glycogen spare\u2019 more effectively and therefore work at higher intensities for longer.<\/li>\n<li>Increased muscle oxygen\u00a0utilisation (a-VO2 difference):\u00a0All of the above listed factors contribute to the body\u2019s ability to attract oxygen into the muscle\u00a0cells and then use it to produce adenosine triphosphate (ATP) for muscle contraction. A\u00a0measure of this is the difference in the amount of oxygen in the arterioles in comparison to the\u00a0venules.<\/li>\n<li>Increased muscle fibre\u00a0adaptation:\u00a0Some research has indicated that skeletal muscle fast-twitch type 2A can take on some of the\u00a0characteristics of slow-twitch as an adaptation of aerobic training. This would allow for a greater\u00a0ability to generate ATP aerobically with fewer fatiguing factors.<\/li>\n<\/ul>\n<p>All Three Systems &#8211; Cardiovascular, Respiratory and Muscular<\/p>\n<ul>\n<li>Increased VO2 max: An increase in the maximum oxygen uptake (VO2 max) allows for a greater amount of oxygen\u00a0that can be taken in by the respiratory system, transported by the cardiovascular system and\u00a0utilised by the muscular system to produce ATP, improving the economy of the athlete.<\/li>\n<li>Increased lactate inflection point (LIP): LIP represents the highest intensity point where there is a balance between lactate production\u00a0and removal from the blood. The advantage of having a higher LIP is that the anaerobic\u00a0glycolysis system isn\u2019t contributing as much until higher exercise intensities are reached. This\u00a0means that the athlete can work at higher intensities for longer periods without the fatiguing\u00a0hydrogen ion accumulation.<\/li>\n<\/ul>\n<p><script src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\" async=\"\"><\/script><br \/>\n<ins class=\"adsbygoogle\" style=\"display: block; text-align: center;\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\" data-ad-client=\"ca-pub-0127150553352455\" data-ad-slot=\"7834404329\"><\/ins><br \/>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><br \/>\n<strong>Chronic <em>anaerobic<\/em> adaptations to training<\/strong><\/p>\n<p>Muscular<\/p>\n<ul>\n<li>Muscular hypertrophy: An increase in muscle fibre size due to an increase in the size and number of myofibrils and the\u00a0protein filaments actin and myosin. This increase in muscle size allows for a greater production\u00a0of strength and power.<\/li>\n<li>Increased muscular stores of\u00a0ATP and CP:\u00a0Increased muscular stores of ATP and creatine phosphate (CP) increases the capacity of the ATP-CP system, allowing for faster resynthesis of ATP for high intensity activities.<\/li>\n<li>Increase in ATPase and creatine\u00a0kinase enzymes:\u00a0ATPase is responsible for breaking down ATP to form ADP and release energy for muscular\u00a0contraction. Creatine kinase initiates the breakdown of CP, which provides the energy to resynthesise ATP at a fast rate.<\/li>\n<li>Increased glycolytic capacity: Increased muscular storage of glycogen and consequently the increased levels of glycolytic\u00a0enzymes, enhances the capacity of the anaerobic glycolysis system to produce energy.<\/li>\n<li>Increase in the number of motor\u00a0units recruited:\u00a0An increase in the number of nerve axons and their corresponding muscle fibres increases the\u00a0power and strength of muscular contractions.<\/li>\n<li>Increased lactate tolerance: An increase in the ability of the muscles to buffer (neutralise) the acid that accumulates from the\u00a0production of hydrogen ions during an exercise bout. The increase in lactate tolerance prevents\u00a0the onset of fatigue and allows an athlete to continue to generate ATP anaerobically, which is at\u00a0a faster rate, and allows them to work at a higher intensity, producing high lactate levels at the\u00a0end of performance.<\/li>\n<\/ul>\n<p><script src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\" async=\"\"><\/script><br \/>\n<ins class=\"adsbygoogle\" style=\"display: block; text-align: center;\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\" data-ad-client=\"ca-pub-0127150553352455\" data-ad-slot=\"7834404329\"><\/ins><br \/>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><br \/>\n<strong>Chronic adaptations to <em>resistance<\/em> training<\/strong><\/p>\n<p>Neuromuscular<\/p>\n<ul>\n<li>Increase in the cross-sectional\u00a0area of a muscle (muscle\u00a0hypertrophy):\u00a0An increase in the total quantity of actin and myosin protein filaments, the size and number of\u00a0myofibrils and also in the amount of connective tissue that surrounds the muscle. This allows\u00a0the muscle to create a greater amount of strength and power with each contraction.<\/li>\n<li>Increased synchronisation of\u00a0motor units:\u00a0An increase in the ability for a number of different motor units to fire at the same time and an\u00a0improved ability to recruit larger motor units that require a larger stimulus to activate. The ability\u00a0to recruit more motor units at the same time and to stimulate larger motor units creates a more\u00a0powerful muscular contraction.<\/li>\n<li>Increase in the firing rate (rate\u00a0coding) of motor units:\u00a0An increase in the frequency of stimulation of a given motor unit (rate coding) increases the rate\u00a0of force development or how quickly a muscle can contract maximally. This is beneficial for\u00a0rapid ballistic movements where maximal force is required in a very short period of time.<\/li>\n<li>A reduction in inhibitory signals: The improved coordination of the agonists, antagonists and synergists is thought to allow for\u00a0the reduced inhibitory effect. The reduction in the inhibitory mechanisms allow for a greater\u00a0force production within a muscle group.<\/li>\n<\/ul>\n<p><script src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\" async=\"\"><\/script><br \/>\n<ins class=\"adsbygoogle\" style=\"display: block; text-align: center;\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\" data-ad-client=\"ca-pub-0127150553352455\" data-ad-slot=\"7834404329\"><\/ins><br \/>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><br \/>\n<strong>Summary of cardiovascular and metabolic adaptations with endurance training<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%;\" border=\"1\">\n<tbody>\n<tr>\n<td style=\"width: 35.9589%; text-align: center;\"><strong>Physiological<\/strong><br \/>\n<strong>Parameter<\/strong><\/td>\n<td style=\"width: 17.8082%; text-align: center;\"><strong>Rest<\/strong><\/td>\n<td style=\"width: 25.5137%; text-align: center;\"><strong>Submaximal<\/strong><br \/>\n<strong>Exercise<\/strong><\/td>\n<td style=\"width: 20.7192%; text-align: center;\"><strong>Maximal<\/strong><br \/>\n<strong>Exercise<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Stroke volume<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u00a0\u2191<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Heart rate<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">\u2193<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u2193<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u2193 or &#8211;<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Cardiac output<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">&#8211;<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">&#8211;<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u00a0\u2191<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">a-vO2 difference<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">&#8211;<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u00a0\u2191<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u00a0\u2191<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">VO2<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">&#8211;<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">&#8211;<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u00a0\u2191<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Systolic blood pressure<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">\u2193<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u2193<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">&#8211;<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Diastolic blood pressure<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">&#8211;<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u2193<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u2193<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Blood volume<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u00a0\u2191<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Capillary density<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u00a0\u2191<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 35.9589%;\">Mitochondrial density<\/td>\n<td style=\"width: 17.8082%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 25.5137%; text-align: center;\">\u2191<\/td>\n<td style=\"width: 20.7192%; text-align: center;\">\u00a0\u2191<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u2191 = increase; \u2193 = decrease; &#8211; = no change; a-vO2 = (CaO2\u2013 CVO2); VO2 = oxygen consumption.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><strong>References:<\/strong><\/p>\n<ol>\n<li>Rivera-Brown AM, Frontera WR.\u00a0Principles of exercise physiology: responses to acute exercise and long-term adaptations to training.\u00a0PM R. 2012 Nov;4(11):797-804. <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/23174541\/\" target=\"_blank\" rel=\"noopener noreferrer\">[Medline]<\/a><\/li>\n<li>Gabriel BM, Zierath JR. The Limits of Exercise Physiology: From Performance to Health.\u00a0Cell Metab. 2017 May 2;25(5):1000-1011. <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/28467920\/\" target=\"_blank\" rel=\"noopener noreferrer\">[Medline]<\/a><\/li>\n<li>Hellsten Y, Nyberg M. Cardiovascular Adaptations to Exercise Training.\u00a0Compr Physiol. 2015 Dec 15;6(1):1-32.\u00a0<a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/26756625\/\" target=\"_blank\" rel=\"noopener noreferrer\">[Medline]<\/a><\/li>\n<li>Tripp TR, Kontro H, Gillen JB, MacInnis MJ. Fit for comparison: controlling for cardiorespiratory fitness in exercise physiology studies of sex as a biological variable. J Physiol. 2025 Apr;603(8):2219-2230. <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/40120131\/\" target=\"_blank\" rel=\"noopener\">[Medline]<\/a><\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p>Created Nov 08, 2018.<br \/>\nUp-date Feb 10, 2026.<\/p>\n\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Sorry, this entry is only available in Espa\u00f1ol.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"no","_lmt_disable":"no","_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[355],"tags":[356,361,360,357,146,358,359,363,362,364],"class_list":["post-2176","post","type-post","status-publish","format-standard","hentry","category-physical-therapists","tag-adaptaciones","tag-adaptations","tag-aerobic","tag-aerobicas","tag-chronic","tag-cronicas","tag-entrenamiento","tag-fisico","tag-physical","tag-training"],"modified_by":"Guillermo Firman","_links":{"self":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts\/2176","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/comments?post=2176"}],"version-history":[{"count":9,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts\/2176\/revisions"}],"predecessor-version":[{"id":10656,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts\/2176\/revisions\/10656"}],"wp:attachment":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/media?parent=2176"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/categories?post=2176"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/tags?post=2176"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}