Endurance Exercise

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton, Oyemi Sillo and Aminat Abolade  

Introduction

In sport, endurance is the ability to sustain a specific activity (endurance running, cycling, swimming, rowing, cross-country skiing etc) for a prolonged period.

• An endurance sport is any sport in which there is a requirement to sustain an activity level while enduring a level of physical stress.
• Endurance training involves developing both general and event specific endurance. And the mental toughness or “grit” needed to achieve our peak performance.
• The fundamental requirement for any endurance sport is the ability to sustain a submaximal work rate for a prolonged period.

The ability to compete strongly in endurance events is influenced by our physical fitness and psychological strengths

• Endurance training is largely influenced by physiological factors (efficiency of energy systems, aerobic capacity/VO2 max, lactate threshold, muscle strength, power and muscular endurance)
• Psychology also plays a key part in success in endurance sport.

New Insights

The effect of exercise training on muscle phenotype has been appreciated for millennia. In general, individuals who train by exercising for a long time will develop better oxygen delivery to muscle and endurance capacity, whereas those who work against a heavy load will get bigger and stronger muscles. However, recent work using high-intensity short-duration interval training to increase endurance and low-load resistance training to failure to increase muscle size and strength have challenged the classical view of training specificity.

Mitochondrial Biogenesis

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 (ETS), using substrates generated in the tricarboxylic acid (TCA) cycle.

The Role of Supplements

The world of endurance nutrition is continually evolving and the commercial supplement industry is ever-changing. New products with purported benefits are being advertised to athletes as well as the general population, claiming improvements in performance and general health. Elite athletes, after they maximize training adaptations, often look to gain marginal benefits that they believe may be pivotal in their results. They may take supplements and/or adopt new diets faster than medical research can keep up to make sound recommendations. Below summarises the key recommendations for macronutrients, hydration, and supplements.

High carbohydrate diets have long been tested and continues 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. Attention to adequate intake is emphasized to improve recovery, ameliorate muscle damage, and maintain muscle mass. Fats recently have been gaining popularity again, especially with ultra-endurance athletes, although “training low” with a high-fat diet may not necessarily improve performance. 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.

Athletes commonly take supplements, and a few supplements may have merit in the endurance world. Nitrates 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. There is a paucity of quality research on probiotics for athletes, but chronic URI and GI symptoms common in endurance athletes may potentially be attenuated with Lactobacillus and Bifidobacteria supplementation. Additionally, as with any supplement, since the US Food and Drug Administration (FDA) is not authorized to review dietary supplement products for safety and effectiveness before they are marketed, there is the risk of contaminants and illicit substances in commercial supplements. These substances may not only present a safety risk but may be on a banned substance list for professional athletes [92]. While it is recommended that athletes obtain nutrition from whole foods, we acknowledge that athletes may take supplements and recommend they choose from trusted sources.

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