This article was originally published in the May/June 2023 issue of UltraRunning Magazine. Subscribe today for similar features on ultra training, racing and more.
What training is better for getting into ultra distances: muscles or miles? — @kerriwbrady
Endurance sports like ultrarunning, adventure racing and obstacle course racing place considerable strain on the body’s musculoskeletal system. It’s perhaps intuitive to think that preparing for these competitions requires strengthening of the muscles. However, while strength training can reduce the risk of injury and perhaps increase oxygen economy in runners (see below), endurance performance is largely determined by oxygen transport capacity and substrate efficiency. Let’s briefly review these determinants of ultramarathon performance.
There are three main systems that the body uses to generate energy for movement: (i) the ATP-PCr system (also known as the phosphocreatine system) which facilitates short-duration, explosive movements like sprinting or weight training; (ii) the anaerobic glycolytic system, which involves the cleaving of glucose molecules in the absence of oxygen and facilitates high-intensity exercise over short and middle distances; (iii) the oxidative system which uses oxygen to unlock energy from carbohydrates and fats, sustaining moderate-intensity exercise over long periods. Although all systems work simultaneously and synergistically, ultramarathons depend primarily on the oxidative system—that is, the ability to supply oxygen to the muscles and use it economically during exercise. Another component of ultramarathon performance is the ability to sustain muscle contractions and endure the associated muscle damage and fatigue. All such mechanisms are developed mainly through endurance exercise at moderate intensities performed for increasingly longer periods of time: “miles” are more important than “muscles” for getting into ultra distances.
Having said that, I’m a firm advocate of strength training for ultramarathon runners because, notwithstanding its potential benefits on running economy, strength training is generally thought to reduce injury risk. Injuries are common in ultrarunning (Scheer et al., 2022) because any pre-existing weaknesses or strength imbalances—in the ankles, knees or hips—will likely be exposed by high mileage running over tough and technical terrain. In fact, about 90% of ultrarunning-related injuries are “overuse” injuries mainly affecting the lower limbs. One published review showed that for every 10% increase in strength training volume there was a 4% decrease in the risk of sports-related injury (Lauersen et al., 2018). As such, strength training is particularly useful as a form of “pre-habilitation.”
If we consistently have stomach issues in ultras and vomit a lot, are we doing damage to internal organs by continuing to run these? –@brittanywatr
Under normal conditions (i.e., when not running an ultramarathon), vomiting occurs because signals are sent from the gastrointestinal tract (for example, when it has become irritated and inflamed during gastroenteritis) to the emetic center of the brain (situated in the medulla) (Heckroth et al., 2021). Similar signals may be sent from sensors that detect balance and visual and chemical disturbances (e.g., drug intoxication). During running, emetic signals generally arise because the gut is struggling to tolerate the food and fluids with which it’s being crammed, a process confounded by reduced blood flow to the GI tract owing to long-duration exercise, exercise in the heat or at altitude. Non-steroid anti-inflammatory drugs (NSAIDs) can also reduce gut perfusion and exacerbate stomach issues—another reason to avoid using them during ultras.
While some people are more sensitive to GI distress (which has a prevalence of between 40-80% during ultras), vomiting is an extreme reaction that should not be tolerated as a “normal” response. There are risks associated with vomiting, including potential for tears in the esophagus (the food pipe) and rupture of gastric arteries. Frequent vomiting can also result in medical conditions affecting the teeth, skin and kidneys, and gastrointestinal, cardiovascular and musculoskeletal systems, and it’s axiomatic that the risks increase with frequency. Vomiting during a race also precludes you from meeting your nutrition and hydration needs, increasing your chances of a DNF. Closely scrutinize your nutritional habits when racing, especially your carbohydrate and fat intake. Indeed, a primary nutritional cause of GI distress is the consumption of carbohydrates or fat in concentrations too high for the gut to tolerate (Tiller et al., 2019). A recent analysis showed that nearly half of ultrarunners consumed carbohydrates during racing at a faster rate than they used them (Rauch et al., 2021), predisposing them to carbohydrate malabsorption and GI distress. When GI symptoms start to arise, it would be sensible to slow your pace, even to a stop, and allow your symptoms to subside before they become more serious. Pushing through the nausea is ill-advised. One should also consider “gut training” strategies that have been shown to improve carbohydrate tolerance, increase blood glucose concentrations and reduce GI symptoms during exercise (Costa et al., 2017). If vomiting persists, speak to your physician as there may be medications that can help.
Why am I gaining weight even though I’m training consistently and eating primarily plant-based? –@holly_scala
Being lean is not a prerequisite for ultrarunning. Having said that, performance is negatively affected by body fat percentage (Tanda & Knechtle, 2015) and the best runners tend to have a high aerobic power-to-weight ratio (i.e., well developed aerobic capacities and little superfluous muscle and fat). Going purely on the information you provided in your question, there are several things to consider. First, being “plant-based” is no guarantee of anything. Studies repeatedly show that, in the majority of people, weight management is determined by calories in versus calories out. In other words, losing weight requires a negative calorie balance (burning more calories than you’re taking in) and this can be equally achieved on a plant-based diet, a 100% carnivorous diet or a normal omnivorous diet. The Mayo Clinic states it simply: “Popular fad diets may promise you that not eating carbohydrates or eating a pile of grapefruit is the secret to weight loss. But it really comes down to eating fewer calories than your body is using if you want to lose weight.” (Mayo Clinic, 2023). Second, when it comes to weight management, training is secondary to healthy eating; hence the advice, “You can’t outrun a bad diet.” Exercise specialists argue that although exercise is an essential tool in reducing the risk of cardiovascular disease, Type 2 diabetes and other health conditions, it is by itself insufficient to facilitate sustainable weight loss. In fact, there are many misleading marketing claims that excess weight and obesity result exclusively from a lack of exercise (American Heart Association, 2016).
Let’s contextualize the exercise contribution to calorie balance using a real-world example. If you train for 60 minutes at a moderate to heavy intensity, you’ll burn in the region of 400–600 calories, depending on your body mass, trained status and whether you’re male or female. That’s an expenditure of 2,500 kcals per week from exercise, assuming five sessions per week (which is considerably more than most of the population). That sounds like a lot of energy, but a 14-inch, regular crust pizza will set you back roughly the same amount of calories, meaning that a single celebratory meal nullifies your entire week’s training-related weight loss. The point here is that training by itself is less effective for achieving weight loss than a healthy diet, and considerably less effective than combined training and long-term healthy diet (Schwingshackl et al., 2014). Rarely, medical issues like an underactive thyroid or a leptin deficiency preclude effective weight loss, but this will require primary care intervention. There’s no simple solution (contrary to what you’ll be led to believe by the commercial health and wellness industry), and weight loss becomes harder as one gets older owing to linear age-related decreases in metabolic rate. But perseverance, careful consideration of all contributing factors and maybe some professional help will give you the best chance of success.