‘Nutrition’ Category

  1. Nitrate Supplementation: The Bitter Truth

    July 4, 2012 by Mubz Kamaluddin

    Unless you have been on Mars recently you would have heard some mention of nitrate supplementation. The current hot topic of the sport nutrition world has reached boiling point and has everyone salivating, apart from me. (That’s only because I can’t stand beetroot!)

    The supplement of focus is Nitric Oxide (NO). NO, the ‘Molecule of the Year, 1992’, has for some time now been suspected to aid performance capabilities; particularly during sub maximal aerobic exercise. Over the last year or so its support has increased, to the point where it is being used by many high level athletes across an array of sports. Performance nutritionists at The English Institute of Sport advocate the use of beetroot shots in their triathlete’s and swimmer’s training programmes in the lead up to the London 2012 Olympics Games.

    Beetroot shots have recently arisen as a naturally occurring ergogenic aid, which assist and enhance aerobic exercise performance. Beetroot supplementation prior to exercise has been shown to decrease O2 demand during sub maximal intensities, resulting in a higher exercise tolerance. It has even been reported in some research that beetroot shots work to lower systolic and diastolic blood pressure in healthy volunteers.

    The idea is that during exercise NO plays a fundamental role in maintaining normal vascular function, as it diffuses into muscles and blood vessels resulting in vasodilation (widening of the blood vessels). The consequential increase in blood flow means more O2 to working muscles, resulting in a ‘harder/better/faster/stronger’ performance, right? Well, in a way yes!

    The literature suggests NO levels are important in O2 consumption rates in active muscles. NO has been found to influence O2 utilization, modulating muscle contraction and muscle glucose uptake. Nitrates allow blood flow to match O2 requirements, providing regular supply within skeletal muscles, thus increasing muscle function. NO also interacts with enzymes in the mitochondrial respiratory chain. This is a process by which energy (ATP) is generated in aerobic activity.

    NO supplementation lowers the O2 cost (the amount of O2 used by the muscles during exercise) of sub maximal activity, suggesting an increase in the ability to meet exercise demands of intensities between 44-89% of VO2 max. VO2 max is the maximum volume of O2 the body can consume per minute.Research shows that on average VO2 (not to be mistaken for VO2 max!) decreases from 2.98Lmin-1 to 2.82Lmin-1 during nitrate supplementation over lower exercise intensities. These findings agree with previous mentioned literature, in that O2 cost of sub-maximal exercise is reduced following NO supplementation.

    So, as you can see NO’s emergence as one of the hottest sport nutrition supplements is warranted. The benefits and advantages provided by NO, especially for athletes in aerobic sports are very impressive. However, beetroot shots are not some magical potion and its key they are integrated into and used alongside a correctly constructed training programme. Also, it must be noted that nitrates are essential micronutrients that everyone must have as part of a balanced diet and healthy lifestyle. Beetroot is excellent, but spinach, rocket and lettuce are a fitting alternative for the health-aspiring non athlete.

    There you have it; the power of NO!

    Thanks for reading,

    Mubz Kamaluddin

    Category Nutrition | Tags: | 2 Comments

  2. “No carbs before marbs”

    June 4, 2012 by Joe Sumray

    Yes, I suppose I have just admitted to shamefully watching  TOWIE (The Only Way Is Essex), but there is nothing wrong with a bit of light entertainment.

    So, what is the deal with the whole no carbs argument? Everytime you go to the gym you will always hear ‘Joe Bloggs’ talking about how they are cutting out carbs to loose weight. However, I bet Joe Bloggs doesn’t have a clue as to why he is cutting out carbs! Well ‘Joe’, I am here to reveal all…

    Emerging evidence suggests that reducing the intake of dietary carbohydrates is a critically important step in promoting both greater weight loss and greater loss of body fat.

    Now for the why part:

    The supposed mechanisms underpinning a reduction in carbs leading to weight loss are likely to be related to lower blood glucose, and in turn blood insulin concentrations. Carbohydrates, increase glucose concentration in the blood, which then triggers release of insulin.  Insulin’s primary functions as a hormone are to promote storage of blood glucose in skeletal muscle and adipose tissue and to inhibit lipolysis (fat breakdown) and promote triglyceride (storage form of fats) synthesis and storage rather than release, therefore leading to fat gain!

    You are now equipped with the rationale behind the BAFTA award winning shows catchphrase “No carbs before Marbs”. Arent they a clever bunch….

    Unfortunately not, whilst carbs do increase fat gain I wholeheartedly disagree with the motto of no carbs, in order to loose weight. Carbs should never be void from the diet. Carbohydrates play a vital role in many of the bodies processes, just to name one, glucose (a carbohydrate source) is the brains only fuel, so yeah, it is not wise to be cutting those carbs out!

    I advise you to decrease your carbohydrate intake (not get rid of it entirely), and consume the majority of your carbs when you wake up and around your workouts/training. Most of your carbohydrate intake should come in the form of low G.I. foods, such as lentils, beans and figs. This is because low G.I. foods trigger a less sharp and pronounced rise in blood insulin levels.

    To make up for your reduced carohydrate intake, you may want to consider replacing it with protein. Diets moderately high in protein and modestly restricted in carbs and fats may have more benefits in maintaining body weight. Increasing your protein intake will help you to retain more lean body mass when partaking in periods of weight loss. This is because protein has the best satiety (feeling of fullness) promoting effects and the highest thermogenic effect, aswell as the obvious synergism between resistance exercise and increased protein intake, in terms of increasing lean body mass.

    At the end of the day, weight loss boils down to the simple equation: Energy balance = Energy input – Energy expenditure! In order to loose weight your energy expenditure needs to be higher than your energy input (food). In order to maintain weight they need to be equal. Word of warning – do not start some ludicrous diet that restricts your calorie intake to nothing. A healthy balanced diet with regular exercise is the best way to go about things! “All in moderation” ladies and gents!

    Thanks for reading!

    Next week will definitely not feature a blog, due to my exams (Lucky me!)

    Follow on twitter by clicking the icon at the top of the blog!

    Joe

    Category Health and Lifestyle, Nutrition | Tags: | No Comments

  3. ‘Train low, Compete high’

    April 2, 2012 by Joe Sumray

    Endurance athletes know that starting exercise with glycogen stores fully loaded makes for higher intensity workloads and overall better performance during competition. But, this long-held belief of sports nutrition is now being challenged!

    New research points out the benefits of periodically training with low glycogen stores. Termed the ‘train low-compete high concept‘ – meaning train in a glycogen depleted state and compete with high glycogen stores. This is an interesting concept that has left many coaches and athletes scratching their heads wondering what it is all about!

    From a cellular perspective training adaptations are the consequence of the accumulation of specific proteins required for sustaining energy metabolism during and after a series of exercise sessions (Hawley & Burke, 2010). However, it has been uncertain whether it is a lack or surplus of a substrate that triggers the adaptation (Coyle, 2000). New molecular insights show that compared with high muscle glycogen content, an acute bout of endurance exercise completed with low muscle glycogen results in a greater transcriptional activation of oxidative enzymes involved in carbohydrate (CHO) metabolism (e.g. AMPK & GLUT4) and an increase in adaptive responses favouring fat metabolism (Hawley et al, 2011). This convincing evidence of enhanced cellular adaptation, following training in a low CHO state triggered the innovative ‘train low-compete high’ concept.

    Hansen et al (2005) conducted the initial investigation into this concept. The 10 wk training study required previously sedentary men to train one leg with a ‘two a day’ training protocol every second day, whilst the opposing leg undertook the same workouts, once every day. The ‘train low’ leg (2x a day every other day), showed significantly greater increases in time to exhaustion accompanied by greater maximal activity of the enzymes: citrate synthase and haloacid-dehalgenase (HAD). These findings have significant scientific merit and possible application for exercise programmes targeting metabolic improvements and health outcomes, however the application of this strategy to improving endurance performance appears to be inconspicuous!

    Muscular adaptation achieved by training provides part of the process by which athletes improve their ability to perform. However, changes in muscle physiology are not necessarily a trigger for performance improvements and currently there is no convincing evidence that train low strategies achieve an enhancement of performance over a conventional diet/training approach (Hawley & Burke, 2010).  The lack of evidence supporting the application of the train low concept for enhancing endurance performance could  be due to the reduced self-selected intensity seen with having low glycogen stores.

    Science2Sport raises a question???

    Evidence shows that a CHO mouth wash during exercise can significantly improve endurance performance. The suggested mechanism behind this is thought to be related to the effects on the central nervous system (CNS). Glucose, is the brain’s only source of fuel and when limited (e.g. during prolonged exercise), the CNS will signal for glycogen utilisation in the muscles to be reduced, in order to spare glycogen (glucose) for the brain. This sparing of glycogen reduces the intensity an athlete can work at, thus a reduction in performance is seen. The CHO mouthwash can act as a signal to the CNS that the body has sufficient CHO stores and therefore will inhibit the signal to induce glycogen sparing, allowing the athlete to maintain a high intensity. Science2Sport asks if the elevated cellular adaptations, associated with the train low protocol could enhance performance, with the aid of a CHO mouthwash?

    Potential limitations of the train low concept:

    - Reduced self-regulated training intensity?

    - Increased risk of injury when glycogen depleted?

    - Increased risk of illness?

    Do not shift to an overall diet of minimal CHO intake:

    Endurance athletes will hamper performance and potentially their health by having a low CHO diet. The train low protocol should be strategically implemented. Below are some ways on how to train low, without having a low CHO diet:

    - Place training sessions close together (e.g. 2x a day every other day)

    - Exercise after an overnight fast

    - Consume water during prolonged exercise

    Concluding statement:

    If you want to incorporate the train low strategy into your training sessions the bottom line is to do it wisely. For example, early in your training cycle, when you are establishing your endurance base and the exercise intensity is low, train low periodically (about 1–2 times per week) to help maximize aerobic adaptation. Build up duration and intensity slowly when training low. As you build up and prepare for increased speed with short speed workouts: while maintaining high mileage, train high, i.e., have high glycogen stores, before your high-intensity speed work; train low, i.e., in a glycogen-depleted state, periodically before endurance workouts. In the latter phase of your training — that time when you transition toward longer-duration speed workouts and decreasing mileage: train high, i.e., have high glycogen stores, in the morning before your speed work; incorporate a same-day second endurance workout in a glycogen-depleted state a few days per week.

    Thanks for reading!

    Subscribe to Science2Sport to receive weekly blogs and follow on twitter and join the fbook group by clicking the symbols at the top of the blog!

    Tune in next week to read how some athletes are bending the anti-doping rules to their advantage!

    Joe

     

    Category Nutrition, Performance and hypertrophy | Tags: | No Comments

  4. ‘The protein myth’

    March 19, 2012 by Joe Sumray

    Calling all muscle building junkies! 

    One of the first things an adolescent male entering his muscle building journey hears about is protein. PROTEIN, PROTEIN, PROTEIN!!!

    Body-builders are known to consume protein intakes far superior to the recommended protein intake. However, the scientific research shows copious amounts of protein are not needed to maximize protein synthesis. Daily protein consumption for people engaging in resistance and endurance exercise should be within the range of 1.3-1.8 grams per kg of body mass per day (g · kg−1 · day−1).

    Perhaps of more importance than the amount of protein being consumed is the type of protein and the timing of intake in relation to exercise.

    Leucine, a BCAA (branched chain amino acid) may be the magic bullet for supporting an anabolic environment, due to its stimulatory role in protein signalling pathways.  Leucine is found in almost all protein-rich foods, such as milk and whey protein.

    When shall I take my protein shake, before I workout, during my workout or after my workout?

    Consuming protein immediately after you workout has been shown to be crucial in maximizing protein synthesis rates. The suggestions are to consume upto 20g of protein immediately after your workout, along with 30-50g of carbs (carbs will be covered in future blogs).

    Concluding statement: 

    The consensus opinion is that leucine, occupies a position of prominence in stimulating muscle protein synthesis; that protein intakes  in the range of 1.3–1.8 g · kg−1 · day−1 consumed as 3–4 isonitrogenous meals will maximize muscle protein synthesis. It is also crucial to intake fast absorbing protein upto 20g immediately after exercise, along with 30-50g of carbs. A pint of milk or a serving of whey protein, along with a carbohydrate rich snack should do the trick!

    Thank you for reading

    Always tired?  Tune in next week to find out why and how you can put a stop to it!

    Joe

     

     

    Category Nutrition | Tags: | No Comments