What’s on your recovery menu? (part 1)
The mainstream population typically refers to recovery as the period and processes required to re-establish normality following injury or illness. Naturally, this concept also holds true for athletes. However, athletes tend to focus on recovery more as a necessity to support their training and competition demands, while also negating co-existing deleterious side effects that increase the risk of illness, injury and diminishing performance. Contemporary knowledge across the overwhelming minefield of recovery methodology is vast. The trick is making the right decisions at the right times – differentiating the hype from reality, and ensuring that you cover off the fundamentals of adapting to training loads, but not slipping into the “free fall” abyss that is every athlete’s nightmare.
In the March edition, we discussed the fundamental principles of the workload-recovery balance. In this (and the following) edition, we extend the boundaries and explore some post-exercise recovery methods that embody both the simple and logical, to the somewhat unconventional.
Should the magic genie bestow you one wish towards improving your athlete prowess “package”, an abundance of energy would surely be a popular choice. Indeed, a significant amount of training and preparation is geared towards improving your economy and energy availability. High volume/moderate intensity, or high intensity/low volume efforts are taxing on muscle and liver glycogen. Given that diminished glycogen stores contribute to a significant proportion of the endurance athlete fatigue paradigm, scientists routinely research new fuelling methods to maximise athletic sustainability and performance.
Nutritional ketosis can be achieved in approximately four days with a strictly adhered to, high fat and low carbohydrate diet, with subsequent preservation of glucose and increased modulation of fatty acids (Pinckaers et al., 2017). In a diabolical situation such as starvation, ketone bodies will provide life-preserving energy for muscle, organ and brain function. For athletes who plan and monitor their performance very carefully, periodic nutritional ketosis may provide a catalyst for important metabolic adaptations.
However, the downside of an athlete practising regular nutritional ketosis is the risk of diminishing muscle responsiveness, and impaired performance.
To theoretically gain metabolic advantages in competition without the risk that comes with a ketogenic diet, supplementing with ketone esters and salts before competition has recently increased in popularity – especially among cyclists and triathletes, as an alternative source of energy (Evans et al., 2016). However, there is currently no conclusive evidence that consuming ketone bodies prior to or during exercise contributes to an improvement in performance.
During recovery, however, recent research by Holdsworth and colleagues (2017) has demonstrated that consumption of a ketone ester drink following exercise, significantly increases skeletal muscle glycogen resynthesis. In this study, 12 well-trained males completed a glycogen depleting exercise protocol and were then subjected to recovery re-feeding via three-way, randomised crossover design; (1) control drink then saline infusion; (2) control drink then hyperglycemic clamp; (3) ketone ester drink then hyperglycemic clamp.
After the ketone ester drink, co-existing with high glucose solution, muscle glycogen was 50% higher compared to the control drink. Considering the typical time course required to fully restore liver and muscle glycogen (24-48hrs) via standard refuelling and adequate rest, these findings are encouraging. The downside is the high cost of ketone esters, and gastrointestinal discomfort commonly experienced by those using ketone salts. Ketone bodies are not lollies, and come with risk – always seek professional advice.
Training for any distance of triathlon comes varying degrees of muscle soreness and risk of incomplete recovery and fatigue disorders. If you know where to look, you will find many natural food extracts with nutrient rich healing properties. Sesame cultivar (Sesamum indicum L.), rich in antioxidants, vitamins and minerals appears to provide noteworthy bang for the buck, as a muscle damage and oxidative stress mediator.
A recent study by da Silva Barbosa et al. (2017) investigated the antioxidant and anti-inflammatory effects of sesame consumption by semi-professional soccer players. Twenty players consumed 40g per day of placebo or sesame over 28 days after routine/heavy loaded training. Baseline measures of muscle and inflammatory blood markers and aerobic capacity were evaluated before sesame ingestion. After 28 days, the experimental group had significantly reduced levels of muscle damage (creatine kinase, lactate dehydrogenase); inflammation (C-reactive protein) and oxidative stress (malondialdehyde). Furthermore, antioxidants (superoxide dismutase, vitamin A, vitamin E) and aerobic capacity significantly increased in the experimental sesame group.
Sesame derivatives are cheap and readily available. There does not appear to be any downside to consumption of sesame, although care needs to be taken on frequency, as protective interventions can also interfere with important adaptations to muscle damage and inflammation when used in abundance.
Once any training session has been completed, athletes turn their attention to re-establishing hydration, muscle glycogen, and minimising muscle soreness. The source of replenishment is key to optimise recovery and will vary according to the previous training load, and with an athlete’s previous response to a variety of products.
A plethora a research over the past 30 years or so, has demonstrated the effectiveness of sports drinks under a variety of circumstances, to deliver energy and fluid during exercise. However, the efficacy of sports drinks following exercise, to promote recovery, remains questionable. Therefore scientists, coaches and athletes commonly experiment with a range of post training beverages, including milk and milk-like products. So, how does milk, or milk-like products, stack up against the more traditional carbohydrate-electrolyte beverage as an ideal recovery drink?
To answer this question, Desbrow and colleagues (2014) subjected 15 males to a rigorous intermittent cycling protocol, inducing a 2% loss in body mass. Participants replenished with a variety of beverages (cow’s milk, soy milk, Sustagen milk-based supplement and Powerade sports drink) on four separate occasions, at a rate of 150% body weight loss over one hour. Furthermore, participants were monitored closely during the four-hour period after that, via urine, blood, body mass and subjective feedback analyses.
Following the trials, milk-based beverages (particularly Sustagen) were retained at a greater rate than the sports drink, as was the feeling of satiety. Plasma volume, electrolytes and thirst rating did not differ between the treatments. Therefore, the milk-based beverages provided a more effective rehydration outcome than the traditional sports drink. Furthermore, milk-based beverages provided superior sources of essential energy, protein and sodium following intense exercise.
The only downside to milk based products for recovery is for those who dislike milk or have a lactose allergy.
That said, lactose-free alternatives are readily available and very cheap.
Let’s face it, many athletes have a yearning for a cold frothy now and then – and don’t they go down a treat when you’re thirsty! We have been led to believe that beer, or any alcoholic beverage for that matter, should be avoided after exercise. To elaborate on misconceptions, a series of experiments were conducted by Desbrow and colleagues to identify the merits of beer as a “sports drink” (2013) and the effects of manipulating alcohol and sodium content of beer on post-exercise rehydration (2015).
During the first experiment (2013), seven males cycled to induce dehydration (~2% drop in body mass) and then were assigned to a range of beer compositions (2.3% low-alcohol; low-alcohol with 25 mM sodium; 4.8% full-strength; full-strength with 25 mM sodium) on four separate occasions. The volume and rate of beverage consumption was the same as the milk experiment previously described. The light beer + 25 mM sodium proved to be the most effective of the four beverages in enhancing net fluid balance and lower urine output.
The second series of experiments (2015) followed identical protocols to the first series (2013), with additional manipulation to the alcohol and sodium content of beverages: low-alcohol with 25 mM sodium; low-alcohol with 50 mM sodium; 3.5% alcohol mid-strength; mid-strength with 25 mM sodium. On this occasion, the light beer with 50 mM sodium was the most effective in regaining and retaining exercise-induced fluid loss. Furthermore, it appears that manipulation of sodium concentration rather than alcohol content per se has a greater impact on fluid retention. If you like beer, you’re in business. If your training-induced dehydration is substantial, let someone else drive!
In the next edition we will focus attention on a range of wearable recovery methods.
Pinckaers PJ; et al. (Sports Med., 2017). Ketone Bodies and Exercise Performance: The Next Magic Bullet or Merely Hype?
Evans M; et al. (J Physiol., 2016). Metabolism of ketone bodies during exercise and training: physiological basis for exogenous supplementation.
Holdsworth D; et al. (Med Sci Sp & Ex., 2017).
A Ketone Ester Drink Increases Postexercise Muscle Glycogen Synthesis in Humans.
Da Silva Barbosa C; et al. (Front. Physiol., 2017).
Effects of Sesame (Sesamum indicum L.) Supplementation on Creatine Kinase, Lactate Dehydrogenase, Oxidative Stress Markers, and Aerobic Capacity in Semi-Professional Soccer Players
Desbrow B; et al. (Appl Physiol Nutr Metab., 2014). Comparing the rehydration potential of different milk-based drinks to a carbohydrate-electrolyte beverage.
Desbrow B; et al. (Int J Sport Nutr Exerc Metab., 2013). Beer as a sports drink? Manipulating beer’s ingredients to replace lost fluid.
Desbrow B; et al. (Int J Sport Nutr Exerc Metab., 2015) Manipulations to the Alcohol and Sodium Content
of Beer for Post-exercise Rehydration.