ISSN Graduate Diploma Podcast

One central tenet that underpins endurance performance is the maximal rate at which an athlete can sustainably maintain aerobic metabolism. The upper limit of which, is determined by measuring an athlete's Vo2 max.

This is the maximal rate at which one's heart can efficiently pump oxygenated blood to working muscles for energy. This is governed by peripheral factors such as the number and mass of mitochondria, its enzyme activity, myoglobin content and capillary density; and central factors, such as pulmonary diffusion, cardiac output and the oxygen-carrying capacity of the blood (Bassett and Howley, 2000).

The most effective method by which blood transports oxygen is via the metallic compound haemoglobin. 

Many endurance athletes undertake various forms of altitude exposure in a bid to increase haemoglobin mass.

However, a factor that remains relatively unexplored is the effects of an athlete's health on haemoglobin adaptation during altitude training; with one emerging determinant of health being energy availability.

With this in mind, today's episode takes a look at a study by Heikura et al. (2018), in which the research group assessed associations between sex, baseline haemoglobin mass, health status, energy availability, hormonal concentrations and bone health on haematological adaptation during 4 weeks of high altitude training in World-Class endurance athletes, 27% of which were Olympians.

If you like the episode, please share it with your friends and other fellow Nutrition enthusiasts.

Soft tissues comprise of muscle, tendons and ligaments.

Soft tissue injuries account for 50% of all injuries in youth sport. In the English Premier League, 60% of all injuries are soft tissue related. In American football, it's almost 70%.

Imagine Liverpool without Mohamed Salah or the Patriots without Tom Brady for sustained periods of the season. Injuries to key players often dictate the success of a team's season.

For years we considered ligaments and tendons, which together I'll refer to as 'sinew', as unresponsive to both training and nutrition. However, we've learnt that this isn't the case. In the presence of training and nutrition, tendons can respond in their metabolic activity and increase in synthesis, producing stronger, larger tendons.

But, with the collagen at the root of tendons remaining dormant in activity and with the composition of sinew being predominantly extracellular proteins, performing biochemistry to analyse how cells within healthy adult sinew respond to nutrition or exercise became incredibly difficult. Thus, science has turned its attention to engineered sinew and research has uncovered some fascinating findings which are shaping nutrition and training recommendations to support soft tissue function and quicken recovery in injured athletes.

In this episode, I share the latest findings in this area.

A special thanks to the stellar work coming out of Keith Baar's lab at the University of California Davis. So much of today's episode was inspired by their work.

Any questions or feedback, never hesitate in reaching out.

In 2009, research by Atherton and colleagues assessed the effects of essential amino acids (EAA's) and their impact on anabolic signalling. 

The group discovered that key signals for muscle growth, being mTORC-1 and 4EBP1 increased in response to the amino acid 'leucine', but not in response to any other EAA. In addition, the important signal of p70S6K1 was increased by all EAA's (with the exceptions of isoleucine and valine), but three times more-so with leucine enrichment [1].

With this and many other papers emerging in the field, demonstrating the anabolic effects of leucine, this protein became chief among the EAA's for increasing the synthesis of contractile proteins.

When ingested, leucine is broken down into alfa-hydroxy-isocaproic acid (α-HICA) and β-hydroxy-β- methylbutyrate (HMB), with both being suggested to offer anabolic benefit.

It was shown that consuming 1.5g of α-HICA in young soccer players increased lean mass and reduced markers of muscle damage, compared to placebo. This was shown, despite players consuming sufficient protein to maximise muscle growth [2].

At present, this is the only published study on this leucine metabolite.

Five percent of leucine metabolism is converted into HMB.

We've known of the potential anabolic benefits of this leucine metabolite since the mid 1990s. Seminal work by Nissan and colleagues revealed that HMB in the calcium form (HMB-Ca), in combination with resistance training, increased muscle mass and improved strength in untrained men [3].

A decade on and with more trained subjects being assessed, the ergogenic benefits started moving from hot to lukewarm.

In a meta-analysis in 2009 by Rowlands and Thomson, it was concluded that HMB supplementation would offer a small, positive effect on strength performance in untrained subjects, but no such effect occurred in trained subjects, along with trivial effects on increases in muscle mass in both groups [4].

A further review in 2013, highlighted that HMB may offer a benefit towards reducing exercise-induced muscle damage and prevent muscle loss during states of chronic disease [5].

By the end of 2013, this was the general, consensus for supplemental HMB.

Just one year later...this consensus changed.

In a series of studies conducted from the same group by Wilson et al. (2014) and Lowery et al. (2016) on a new supplemental form of HMB (HMB-FA), the group showed unprecedented 'steroid like gains' in trained lifters [6][7]. However, these papers since have been heavily critiqued by fellow experts in the field on scientific grounds [8][9][10].

In the most recent consensus statement by the International Olympic Committee (IOC), the benefits attributed to HMB were concluded as being likely achieved by simply maintaining protein intakes at the current set recommendations for maximising muscle hypertrophy (1.6g.kg.bw)[11].

With this in mind, the researchers of today's paper wanted to assess the effects of consuming 'off the shelf' leucine metabolite supplements in conjunction with a resistance training program on muscle thickness and performance. Importantly, the researchers wanted to see if such benefits would occur in the presence of an energy sufficient diet and a daily protein intake that's been suggested to maximise muscle anabolism.

Join me for the next 30 minutes, as I review this great paper and share with you some important take home that will improve your knowledge on the effects of leucine metabolites on body composition and performance.

Special thanks to the great researchers of this paper: Filipe Teixeira, Catarina Matias, Cristina Monteiro, Maria Valamatos, Luís B Sardinha and Stuart Phillips.

References attached in FB post.

Thousands of women across the world pursue physique competitions. Each year, these competitors, dressed in their rhinestone-covered outfits, step on stage among other competitors, displaying their sculpted physiques to a judging panel.

These competitions are judged on a host of aesthetic, appearance criteria, rather than sporting performance. Competitors are critiqued on their muscular size, symmetry, leanness, posing ability, skin tone, and make-up; with each of these criteria ranging in significance depending on the physique category.

The preparation towards stepping on stage, demands a combination of prolonged calorie restriction, weight training and aerobic exercise; in a bid to decrease body fat and preserve one's muscle. To meet the demands of the marking criteria for such competitions, this journey to stage, can lead to physiological and psychological strain.

Prolonged states of energy restriction in female athletes, in aesthetic-focused sports, has been shown to cause harmful effects on appetite regulation, reproductive functioning and bone metabolism, indicative of the Female Athlete Triad.

In addition, our present understanding of the body composition and physical performance changes that occur with female competitors throughout contest preparation and post competition is limited.

With aesthetic appearance being the key determinant behind a competitors success, understanding, as accurately as possible, the changes that occur throughout, is essential knowledge to refine nutrition and training approaches to deliver best practice guidelines.

To date, previous case studies assessing the body composition of female physique athletes have been limited by using devices that lack an estimate of total body water and hold fixed value estimates for the hydration status of fat-free mass, assuming a 73% hydration.

With all this in mind, the aim of this case study was to provide a detailed analysis of body composition using a modified 4-compartment model and neuromuscular performance changes that take place before, during and after a Physique athlete's competition season.

This episode is by far my most comprehensive to date with plenty of practical take homes if competing or coaching in this domain.

I hope you enjoy it.

Resources:

Excel link for estimating energy availability: https://1drv.ms/x/s!ArfxXLsUFOKfiWEE9yiwn4r-IVFb

US Navy bodyfat percentage estimate: http://fitness.bizcalcs.com/Calculator.asp?Calc=Body-Fat-Navy

Further reading: https://www.dropbox.com/sh/45upzkcoh7g9jwb/AAAeQhFP1725zryMNsahJxvWa?dl=0

Almost 50 percent of our body structure is given over to the complex, multi-nucleated endocrine organ, we call skeletal muscle. 

Packed with cylindrical cells, bundled into compartments, wrapped in connective tissue and delicately interwoven by supplies of blood vessels and nerves, our skeletal muscle is the source of sustenance that influences our health profile as we age. In addition, its composition is a determining factor towards the potential of our athletic performance.

Skeletal muscle orchestrates key roles in carbohydrate and fat oxidation, the storing of glucose, and bears the greatest contribution to our resting metabolism. It also dictates the exchange of chemical energy from the food we consume into adenosine triphosphate (ATP)- permitting muscular contraction and force transmission. 

The maintenance of this complex organ is determined by the protein we consume and the movements we undertake. 

A key question that has occupied the thoughts of many in the fitness community, in a bid to refine their performance is: 'Just how much protein can the human body usefully absorb?' 

In this episode, I'm providing a review on the research behind the question: 'How much protein can the body use in a single meal to optimise the development of skeletal muscle?'

If you liked the podcast, please share it with your friends and other Nutrition enthusiasts.

A special thanks to some of the key researchers who helped mould my thought process in this area:

Stuart Phillips, Oliver Witard, Jorn Trommelen, Kevin Tipton, Robert Wolfe, Alan Aragon and Brad Schoenfeld

Drop link for further reading: https://www.dropbox.com/sh/67m2p3y2ozablh1/AABVu6wGIEuI6JDBvhABUNsma?dl=0

The sport performance-enhancing effects of caffeine are well-founded, particularly in endurance exercise. In research, such results are commonly presented as mean cohort responses. However, when assessing the individual responses of caffeine on sports performance, the ergogenic effects aren't quite so pervasive, with a high degree of individual variability. Although some of this variability can be down to the study design, caffeine dosages and sex-specific differences, there is a growing body of work, that the individuality in the response to caffeine metabolism may be down to our genes.

In this episode, I delve into the research on the modifying effects of the CYP1A2 polymorphism and the subsequent results on a 10km time-trial in male athletes.  

In this episode, I'll cover the history behind the discovery of caffeine, the multiple mechanisms proposed for its ergogenic effects and a review of the recent paper titled: Caffeine, CYP1A2 Genotype, and Endurance Performance in Athletes by Guest et al. (2018). As always, I'll be leaving you with my practical take homes from this research.

If you like the podcast, please leave a review and share it with your friends and other Nutrition enthusiasts.

Till next time, stay curious, think critically and never-stop learning

I'd like to think we've all been there, at least once. That feeling of waking up in the morning, after that tough workout, only to find that building contractors have moved in and poured concrete where your thigh muscles used to be. Your calves feel strung like a ukulele and your glutes feel on the verge of bursting.

This is technically classified as a grade 1 strain injury and a subset condition of exercise-induced muscle damage (EIMD), referred to as delayed onset muscle soreness (DOMs).

For some, this means re-baselining physical exertions for the next 72 hours and rethinking standard tasks like climbing stairs and sitting on the toilet. For others, degrees of muscle soreness can permeate for an entire sporting season.

In light of this, many athletes opt for non-steroidal anti-inflammatory drugs such as NSAIDs (Aspirin, Ibuprofen) to help fasten recovery and reduce exercise-induced pain.

In some high-collision elite sports, the psychological consequences of enduring constant soreness can lead to the addiction of prescription pain-killers. With this in mind and the growing evidence supporting NSAID's effects on impairing muscle growth signalling, a recent interest in antioxidant-enriched functional foods has been explored to provide a natural alternative.

In today's episode, I'm addressing a past paper, titled: 'Effects of powdered Montmorency tart cherry supplementation on an acute bout of intense lower body strength exercise in resistance trained males' by Levers et al. (2015).

In this episode, you'll learn about inflammation and free radicals and how such physiological responses can be both beneficial and detrimental to adaptation and repair, depending on the context.

You'll learn about tart cherries track record on reducing markers of muscle damage and if such a supplement is worth adding to your performance nutrition toolbox.

If you end up liking the podcast, please leave a review and share it with your friends and other Nutrition enthusiasts.

If you have any questions, please email me at [email protected]

Until next time, stay curious, think critically and never-stop learning

Episode three:

Without question, one of the most important adaptations for improving endurance performance is to increase the mass of mitochondrial proteins. This allows for the closer matching between energy demands and energy production. This adaptation is accompanied by increases in capillary density, energy transport proteins and an increase in enzymes in the key pathways for aerobic metabolism. In a concert fashion, this allows for the muscle to work at the same absolute intensity, but requires less oxygen uptake, impinging less on cellular maintenance and as a result, taking further strides towards that ultimate goal of endurance training, which is; getting sustainably faster.

Since the dawn of the current 'Molecular Age of Exercise Physiology', it's been found that the glycogen granule operates beyond its conventional role of branched energy. It is, in fact, a key regulator of cell signaling and gene expressions that transform the muscle towards greater efficiency of energy-use during aerobic metabolism.

To date, results have shown repeatedly, that phases of reduced carbohydrate availability can increase skeletal muscle markers of training adaptation; such as mitochondrial enzyme activity and its content and whole body and intramuscular fat oxidation. At present, roughly 40% of studies implementing this strategy have shown improvements in performance.

In this episode, I'll be sharing with the listener the main models used for training with low carbohydrate availability and practical considerations to ensure you use this tool effectively. Finally, I'll be touching on the recent 'glycogen threshold' hypothesis.

This episode is teeming with useful information.

If you like the podcast, please leave a review and share it with your friends and other Nutrition enthusiasts.

Until next time, stay curious, think critically and never-stop learning.

Episode two:

Almost a century ago, two inquisitive Danes by the names August Krogh and Johannes Lindhard offered one of the first insights into what today, we consider a cardinal tenet of Sports Nutrition practice; which is: When looking to perform at one's best, having enough available carbohydrates is essential for endurance performance.

The two Danes found that the amounts of fat and carbohydrate used for energy during exercise varied with the amounts consumed in the preceding diet. As a result, they found that carbohydrates produced more energy for a given volume of oxygen consumed compared to fat during exercise.

Despite this understanding, recent intrigue in the field of Exercise Metabolism has looked upon circulating blood ketone levels as an energy source that could enhance performance by providing an alternate oxidative substrate for exercising muscle; sparing our limited stores of muscle glycogen. This is attained by consuming a low carbohydrate, high fat diet. However, such results on exercise performance haven't lived up to their anecdotal hype, when put under the microscope in Science. The majority of studies have demonstrated that carbohydrate use during exercise becomes impaired in such conditions. As a result, in the presence of high-intensity exercise, the use of ketone bodies and fatty acids for energy doesn't offer the same performance improvements compared to the consumption of a high carbohydrate diet.

Echoing results from almost 100 years ago.

However, this has led to researchers exploring supplemental ketones as another strategy to alter aerobic energy use, but this time, without manipulating dietary carbohydrate intake.

Initial research has looked promising, but what impact would a ketone supplement have when used with world class elite cyclists studied under race-like conditions?

Would such a supplement offer any benefit in this scenario?

Find out in this episode.

Episode one:

What does energy availability mean?  Is there a threshold of low energy availability where this starts to negatively impact on reproductive functioning? How can you quantify energy availability? Are there sex-based differences in bone metabolism, when energy availability is low? What can you do to combat low-energy availability from occurring?

These are just a few questions answered in this episode.

In today's podcast, I'll be taking you through the recent paper titled: 'Effects of reduced energy availability on bone metabolism in women and men' by Papageorgiou, et al., (2017).

In just 20 minutes, I'll share with you the latest research on low energy availability, the effects this can have on bone metabolism and you'll gain access to the most up-to-date, 'evidenced-informed' excel tracker to track yours and your client's energy availability status currently available on the web.

If you liked the episode, please share it with your friends and other nutrition enthusiasts.

I'll be back on the 25th of June with episode two. 

In the meantime, stay curious, think critically and never-stop learning.

ISSN Graduate Diploma Energy Calculating Spreadsheet: Excel calculator

Reading list: Research papers