Endurance Exercise

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton, Oyemi Sillo and Aminat Abolade  

Introduction

The fundamental requirement for any endurance sport is the ability to sustain a submaximal work rate for a prolonged period. Examples include cycling, swimming, rowing, cross-country skiing etc. The ability to compete strongly in endurance events is influenced by our physical fitness and psychological strengths

• Endurance training involves developing both general and event specific endurance. And the mental toughness or “grit” needed to achieve our peak performance..

• Endurance training is largely influenced by physiological factors (efficiency of energy systems, aerobic capacity/VO2 max, lactate threshold, muscle strength, power and muscular endurance). V02 max is defined as the maximal volume of oxygen that the body can deliver to the working muscles per minute. See also exercise physiology
• Neuromuscular Adaptations to Exercise and Psychology also play a key part in success in endurance sport.

Types of Endurance Exercise

Endurance exercise means a general ability to do any kind of physical activity that increases your heart rate above 50% of your maximum. It can be divided into general endurance and specific endurance.

1. Specific endurance is the ability to stand against fatigue in sport specific conditions. The better the sport specific endurance, the better performance at this specific sport. It can be characterised as a combination of various types of endurance needed to maximise the ability to succeed in the discipline. eg, if you’re a 1500m runner, you use a combination of endurance training methods to perform better at your specific distance.
2. General endurance characterises the ability of the whole body to tolerate endurance exercises and diminish fatigue. The better your general endurance the better you can stand longer efforts at various sports disciplines. eg, if you are a 30 km cyclist you have a high level of general endurance, you can perform at a relatively high level also at 100km, but you can’t beat 100 km cyclists who have been developing their distance specific endurance.

New Insights

The classical view of training specificity is that: individuals who train by exercising for a long time will develop better oxygen delivery to muscle and endurance capacity; those who work against a heavy load will get bigger and stronger muscles.

Recent work using high-intensity interval training (HIIT) to increase endurance and low-load resistance training to failure to increase muscle size and strength have challenged the classical view of training specificity.

HIIT

• Is a highly desirable workout, because it engaging all muscle fibers, the fast twitch as well as the slow twitch. This makes anaerobic (HIIT) good for a complete training effect.
• The benefits from anaerobic (HIT) exercise depend on the effort put in. Maximum “effort” by a large muscle mass, such as the legs, produces optimum benefits for the whole body.
• Typically, a HIIT workout will range from 10 to 30 minutes in duration.

Adaptations in Skeletal Muscle

Endurance training leads to adaptations in both the cardiovascular and musculoskeletal system that supports an overall increase in exercise capacity and performance.

The local adaptations in skeletal muscle, such as increased mitochondrial biogenesis and capillary density, aid in the body’s ability to transport and use oxygen to generate energy and therefore delay the onset of muscle fatigue during prolonged aerobic performance. The mitochondrion is the main organelle for energy production through the generation of adenosine triphosphate (ATP) via the electron transport system.

Cardiovascular Adaptations

Aerobic exercise training leads to cardiovascular changes that markedly increase aerobic power and lead to improved endurance performance. The functionally most important adaptation is the improvement in maximal cardiac output which is the result of an enlargement in cardiac dimension, improved contractility, and an increase in blood volume, allowing for greater filling of the ventricles and a consequent larger stroke volume. In parallel with the greater maximal cardiac output, the perfusion capacity of the muscle is increased, permitting for greater oxygen delivery. To accommodate the higher aerobic demands and perfusion levels, arteries, arterioles, and capillaries adapt in structure and number. The diameters of the larger conduit and resistance arteries are increased minimizing resistance to flow.

• Cardiac dimension: The thickness of both, the septum and posterior wall increases to the same extent as the interior volume. The mass/volume ratio, and therefore the maximum systolic wall stress, remains constant in contrast to pathologic forms of hypertrophy.

Endurance Exercise Performance in Ageing

Peak endurance performance is maintained until ∼35 years of age, followed by modest decreases until 50–60 years of age, with progressively steeper declines thereafter. Among the three main physiological determinants of endurance exercise performance (i.e. VO2 max, lactate threshold and exercise economy), a progressive reduction in VO2 max appears to be the primary mechanism associated with declines in endurance performance with ageing.

Masters endurance athletes are capable of remarkable athletic and physiological functional performance, thereby representing a uniquely positive example of ‘exceptional ageing’. Nevertheless, endurance exercise performance decreases during middle-age and declines at an even more rapid rate in older age.

Image: Antonio Molinari (born 13 February 1967) World Masters Mountain Running Championships 2021, a course of 7.4 kilometres involving a climb of 775 metres

The Role of Supplements

The world of endurance nutrition is continually evolving and the commercial supplement industry is ever-changing. Elite athletes, after maximising training adaptations, often look to gain marginal benefits with supplements. It is recommended that athletes obtain nutrition from whole foods. However athletes often look to supplements. Below summarises the key recommendations for macronutrients, hydration, and supplements.

• High carbohydrate diets continue to be recommended in endurance athletes. Most endurance athletes are familiar with high carbohydrate diets, but the importance of protein (both total daily intake and immediate post-exercise consumption) may not be as well-known by athletes. Adequate intake of protein is emphasized to improve recovery, ameliorate muscle damage, and maintain muscle mass.
• Fats recently have been gaining popularity again, especially with ultra-endurance athletes.
• There has been a shift away from forced hydration plans and personalizing fluid intake according to thirst and sweat rates to avoid exercise-associated hyponatremia. To reduce this risk fluid intake should be limited to 300–600 mL per hour in ultra-endurance races.

Athletes commonly take supplements, and a few supplements may have merit in the endurance world.

• Nitrates are a vasodilator. Vasodilators widen (dilate) the blood vessels, improving blood flow and allowing more oxygen-rich blood to reach the heart muscle. They may help reduce oxygen cost and improve time to exhaustion, possibly cardiorespiratory performance at anaerobic threshold, and even VO2max. Studies are mixed however, and nitrate may preferentially benefit non-elite recreational athletes.
• Antioxidants may help an athlete who has already peaked in terms of training adaptation, where the main goal is facilitating recovery and earlier return to competition in multi-stage events.
• Caffeine has a very large body of research behind its ergogenic effects, with side effects being the main limiting factor.