‘Performance and hypertrophy’ Category

  1. ‘Lactic acid – innocent until proven guilty (the defence)’

    August 6, 2012 by Joe Sumray

    Guess what readers? Your PE teachers, coaches, gym instructors, TV presenters & Colin Jackson are all wrong! It was yesterday evening around about 7 o clock when Colin Jackson was providing his glitzy overview of the physiological/biochemical underpinnings behind the 400 metres. A passing note from Colin went along the lines of  ’….and that is when the lactic acid builds up, causing fatigue to set in’. Colin’s victimization of lactic acid angered me, prompting me to act, in order to defend and repair the broken reputation of  our very own Mr Lactic acid. Everyone is entitled to a defence lawyer!

    Since the early 1900′s it has been known that isolated muscles made to contract until fatigue accumulate lactic acid. In addition, if oxygen is present in recovery, lactic acid levels decline while glycogen concentration & contractile function are restored. Hence, the rise of the well publicised association between oxygen insufficiency, lactic acid and fatigue.

    More recently, beneficial effects of lactate and lactate acidosis have been reported. For example, lactate can act as a substrate for energy production and is involved in cell-cell signalling. Further, lactic acid clearance during exercise has been thought to provide a beneficial, alkalising, effect on blood pH. Lactate transport across membrane barriers are now known to be facilitated  by lactate transport proteins that co-transport lactate and hydrogen ions (hydrogen ions are a major cause of fatigue). More over, several lactate transporter isoforms are expressed in different tissues and occupy specific cells. Therefore, production and exchange of lactate infact has many beneficial roles, with some aiding the reversal of fatigue.

    Results for Nielsen et al (2001) require us to once again re-evaluate our notions of lactate and its acidosis as some sort of fatigue inducing monster. Granted the study was performed on rats, Nielsen et al describe how muscular contractions cause both lactic acidosis and loss of intracellular potassium ions with accumulation of extracellular potassium ions. They observed that high potassium ion levels lead to a loss in muscular force. However, when lactic acid levels were high muscle fatigue wasn’t evident. In contrast, lactic acid actually countered the effects of potassium ions, that are observed with fatigue.

    Such discoveries challenge the notion that lactic acid is the main cause of fatigue.  I suggest we all stop victimising lactic acid and start ganging up on those nasty potassium ions and hydrogen ions instead! (Note – Science2Sport doesn’t promote victimising, bullying or any related behaviours).

    ‘Your honour, I propose my client, Mr Lactic Acid innocent’ 

    Thanks for reading! Keep tuned for your next dose of Science2Sport! Coming up we have an exclusive interview with a GB handball player, courtesy of our very own guest blogger Mubz (follow on twitter @MubzKamaluddin).

    Joe

    Category Performance and hypertrophy | Tags: | 3 Comments

  2. ‘Hamstring strains – causes and prevention’

    July 16, 2012 by Joe Sumray

    Apologies for the lengthy delay in blogging action. I have been celebrating my recent graduation and haven’t found time to get my blogging hat on (may have something to do with excessive alcohol consumption). I hope you all enjoyed the guest blog last week! Follow Mubz on twitter for more S2S action! (@mubzy4 & @MubzKamaluddin)

    This blog will cover the causes of those annoying, niggling hamstring injuries and provide you with a guide to prevent such injuries from occuring!

    Within the world of football, hamstring strains are the most frequently occurring injuries. Hamstring strains account for approximately 12% of all injuries and on average result in 18 days out of action. Studies show that 91% of hamstring strains are non-contact, with 57% occurring in the late swing phase. The late swing phase is the point at which muscle activity is the highest and the hamstrings are working eccentrically, to decelerate the forward movement of the quadriceps.

    Risk factors for hamstring strains:

    - Inadequate warm-up & fatigue (extrinsic factors)

    - Agonist-Antagonist strength imbalances (i.e. quadriceps-hamstrings ratio)

    - Bilateral strength imbalances (i.e. differences between opposing legs)

    - Lack of flexibility

    - Age

    - Low back pain

    - Sacroilliac joint dysfunction

    In order to reduce your chances of suffering a hamstring strain, it’s important to address the risk factors above. A number of studies have looked to reduce the occurrence of hamstring strains by balancing the quadricep:hamstring ratio. One such study, separated 462 soccer players into 4 different groups, after assessing strength imbalances (47% were classified as imbalanced). The 4 groups were: 1) Balanced prior to intervention 2) Imbalanced prior to intervention (no compensation training) 3) Imbalanced prior to intervention (compensation training until balance achieved) 4) Imbalanced prior to intervention (compensation training, but balance achieved unknown). The results showed that injury frequency was 4 fold higher for participants in the imbalanced group (group 2) compared with participants from the balanced group (group 1). Furthermore, compensation training reduced injury frequency to the same rate as participants from the balanced group.  The group who received compensation training, but balance unknown (group 4) didn’t attain as strong a reduction in injury  occurrence. This study shows that compensation training to achieve a more balanced Q:H ratio is successful in reducing injury frequency, and that it’s vital for progress to be monitored.

    Many studies have demonstrated a reduction in hamstring strains following hamstring eccentric strength training. As mention earlier, hamstring strains most frequently occur during the late swing phase, when the hamstrings are working eccentrically to decelerate the forward acceelration of the quadriceps. Therefore, increasing the hamstrings eccentric strength is likely to reduce the risk for injury. Nordic hamstring curls are a great way to increase eccentric strength. Have a search on ‘youtube’ for some great demonstrations!

    Concluding statement: 

    In order to reduce your chances of suffering a hamstring strain Science2Sport recommends taking a holistic approach that targets the risk factors. You should include a sufficient warm up, core stability work, flexibility exercises, proprioception exercises, agility exercises and neuromuscular exercises (i.e. increase hamstring eccentric strength, balanced Q:H ratio, balanced opposing legs).

    Thanks for reading! Follow on twitter (@SciencetoSport or click the icon at the top) for insights, debates, questions and answers on the world of science and sport!

    Best wishes

    Joe

     

     

    Category Health and Lifestyle, Performance and hypertrophy | Tags: | No Comments

  3. Football nutrition – pre, during and post match strategy

    May 28, 2012 by Joe Sumray

    As a football (soccer for our friends across the pond) enthusiast I have decided to provide you with a brief (due to my impending exams) nutritional strategy, to maximize both performance during a game and recovery after a game. These guidelines apply for all intermittent team sports (e.g. rugby)!

    1) Pre-match strategy:

    It is important for players to ensure they maximize glycogen (storage form of carbohydrate) stores prior to a game.  The development of fatigue during a game appears to be related to depletion of muscle glycogen stores. Krustrup et al (2006) found that whole muscle glycogen decreased by 43% during a football match and that almost half of the muscle fibres were completely, or almost empty of glycogen after the game. Depleted carbohydrate stores have been found to negatively effect psychological confidence. This is because glucose is the brains only fuel source. When carbohydrate stores are low, the brain will send a signal to the muscles to ‘spare’ glycogen, resulting in termination of exercise (not quite as simple as that but you get the point).

    In order to maximize glycogen stores it is recommended to consume a low GI rich carbohydrate meal about 3 hours before exercise. It is genuinely considered detrimental to consume carbohydrate less than an hour before a match (however evidence is not conclusive). Sherman et al demonstrated that ingestion of 312 grams of carbohydrate 4 hours prior to strenuous exercise resulted in a 15% improvement in exercise performance, whereas no improvement was observed in the group that consumed carbohydrate 45 minutes prior to exercise. Consuming a low GI meal is also important. GI, aka glycemic index is a measure of the effect of carbohydrate on blood insulin levels. A high GI food results in a quicker and more pronounced insulin response than a low GI food. Recent findings have shown significant improvements in both running time-to-exhuastion and time trial following ingestion of low GI foods, compared to high GI foods consumed 3 hours before exercise. An example of a good pre match nutrition strategy would be to consume 1-4 g/kg during the 6 hour period before exercise, no later than 3 hours prior to exercise. An example of a good pre-match meal would be a large serving of porridge, with milk and a banana (No later than 3 hours before the game).

    2) During the match:

    Intermittent sports, lasting over an hour, such as football are thought to benefit from carbohydrate ingestion during a match. Ali.A et al concluded that ingestion of a carbohydrate-electrolyte solution during exercise enabled subjects with compromised glycogen stores to better maintain skill and sprint performance when ingesting fluids alone. Therefore, sports drinks such as Lucozade have been found to improve performance. Get yourself a supply of sports drinks, or alternatively make your own. Some sugar free orange squash with a couple of pinches of salt should do the trick! Aswell, as ensuring adequate supply of carbs during the match, a sports drink will also help replace fluid and electrolyte losses.

    Mechanisms by which supplementary carbohydrate during exercise enhances performance:

    - provision of an additional muscle fuel source, when glycogen stores become depleted

    - glycogen sparing

    - prevention of low blood glucose concentrations

    - effect on the central nervous system (brain and spinal cord)

    3) Post match strategy

    Post match strategy is all about replenishing your glycogen stores! When periods between training are <8 hours carbohydrate should be ingested as soon as practically possible. Immediately after exercise is a crucial time to replenish glycogen stores. Moderate and high carbohydrate GI foods provide a readily availiable source of carbohdrate for glycogen synthesis. Another tip is to choose nutrient rich snacks to aid recovery. The optimal carbohydrate quantity is about 1-1.5 g/min after exercise. Examples of mod-high G.I. foods include honey, pasta and most rice. Nutrient rich snacks include flavoured youghurt, smoothies, etc.

    Supplements for consideration:

    Protein

    Creatine

    Caffeine

    Nitrate

    Buffers

    Concluding statement:

    Prior to a match a low G.I carbohydrate rich meal should be consumed no later than 3 hours before. Carbohydrate ingestion, via sports drinks during a game has been shown to improve performance. Glycogen resynthesise should start as soon as possible with consumption of a moderate-high GI meal.

    Full time!

    Thanks for reading!

    This may be the last blog for a good couple of weeks, due to the joys of final year exams! Keep upto date with Science2Sport by following on twitter (click the icon at the top).

    Joe

    Category Performance and hypertrophy | Tags: | No Comments

  4. ’5 ways to mix up your workouts and breakthrough any plateau!’

    May 21, 2012 by Joe Sumray

    Working out, but not seeing results? Reached a plateau?….. What you need is to change things up and add a bit of variety to your workouts.  ‘Variety is the spice of life’

    Here are my 5 plateau defeating recommendations:

    (1) Mix up those sets and reps….

    Maximize muscle fibre stimulation by mixing up your sets and reps. Why not try 5 sets of 5 reps to add strength, or 3 sets of 15 to tone up those muscles. To keep achieving gains you have to keep the muscles guessing, changing up the sets and reps is a great and easy way to add variety to your workouts. I have always used a variety of sets to reps ratios within my workouts. For example, a typical chest workout would include: incline BP 5×5, flat DB press 4×8-12, dips 4×12-15 and cable flyes 2×25.

    (2) Change the tempo….

    The rule of thumb for a given rep is usually 3:1:1, meaning the weight should be lowered for a total of 3 seconds, then held in position for 1 second and powered up for one second. The tempo can be changed up to spur on new gains! Why not try a ratio of 6:2:1 or 3:3:1? Keep changing up your rep tempo and you will be sure to see new gains!

    (3) Get creative – supersets, dropsets, in-set supersets, negatives….

    Add variety into your workouts by including an array of techniques to spur on new muscle growth. Superset and dropsets are great ways to increase muscular endurance, feel the ‘pump’ (Arnie’s favourite) and fight off those nasty plateau’s. Supersets are when you perform two exercises back to back without any rest. Supersets can be performed on the same muscle group (e.g. Bench press followed by DB flyes) or with different muscle groups (e.g. bicep curls followed by tricep extensions). In set supersets are when you perform two exercises within the same set. I feel they are a great way to stimulate the muscle and ideal for home-workouts where you may not have access to heavy weights, so require different ways to maximize muscle stimulation. A great example is DB bench press performed for one rep followed by a DB flye for one rep, and so on….

    (4) Full body vs Split routines….

    This is a rather touchy topic! Everyone you ask seems to have a different preference with regards to using full body workouts or split routines. To avoid upsetting anyone I am going to say why not try both? Why not do an 8 week block of a split routine, followed by 8 weeks of full body workouts. Why not even use full body workouts and split routines within the same block. To avoid us being here all day I will save going into detail for a later blog. Watch this space!

    (5) Change your exercise order….. 

    If you have hit a plateau in one exercise why not trade it for something else or put a different exercise at the start of your workout. This allows you to make gains in a new exercise. For example, many people start chest days with flat bench press, why not start with incline bench press? Personally, I think starting with incline bench is a better option anyway. You should look to build your chest from top to bottom, to get better proportions and get them top buttons popping open!

    Get experimenting with these 5 tips and you will be sure to spur on new muscle growth! Remember, summer is only around the corner!

    Thanks for reading!

    Subscribe and follow on twitter by clicking the icon at the top of the page!

    Joe

     

    Category Health and Lifestyle, Performance and hypertrophy | Tags: | 1 Comment

  5. ‘Train less to be the best – Interval training for endurance running’

    May 14, 2012 by Joe Sumray

    ‘I would love to run a marathon but do not have the time to train for it’

    If you share this misconception, that competing in endurance based events requires endless hours of mind-numbingly boring cardio you are wrong and I have a soloution!

    The research shows that training time required is considerably less than traditionally thought necessary for aerobic adaptations to occur. Sport scientists have found that reducing your training volume by engaging in speed-interval training will not only catylyse the necessary aerobic adaptations, but lead to more pronounced adaptations than that of traditonal endurance training.

    Interval training is a form of physical training that involves bursts of high-intensity work interspersed with periods of low intensity work. The high intensity periods are typically at or close to maximal anaerobic capacity (>80% VO2 max), while the recovery periods may involve either complete rest or activity of low intensity.

    Gunnarsson & Bangsbo (2012) looked at the effect of an alteration from regular endurance to interval training on the health profile, muscular adaptations, VO2 max & running performance. Moderately trained individuals were divided into either a high intensity training group (10-20-30) or a control group (normal cardio training). The high intensity training protocol replaced normal endurance training with 10-20-30 training consisting of low, moderate & high speed running (<30%, <60% & >90% of maximum intensity) for 30, 20 & 10 seconds respectively, in 3-4 five minute intervals interspersed by 2 minutes of recovery.

    After the intervention period VO2 max in the 10-20-30 group was 4% higher & performance in a 1500m & 5k run significantly improved. Systolic blood pressure (SBP) was reduced along with total and LDL cholesterol. No alterations were observed in the control group. This study shows that interval training can improve performance & VO2 max despite a 50% reduction in training volume. In addition, the 10-20-30 training regieme lowers SBP and blood cholesterol, suggesting a beneficial effect on the health profile of already trained individuals.

    Studies done by Burgomaster et al (2005) & Gibala et al (2006) also show the benefits of speed interval training (SIT) over endurance training (ET). Both studies showed enhanced adaptations in muscle oxidative properties and an increased time to exhaustion in the SIT group, compared with the ET group.

    Emil Zatopek was a 5km, 10km and marathon  Olympic champion in 1952. Emil was ahead of the field and the science:

    “When I was young, I was too slow…. so I thought, I must learn to run . So I ran one hundred metres very fast…. People said, “Emil,
    you’re crazy. You are practising to be a sprinter. You have no chance.” … so I said, “Yes, but if I run one hundred metres twenty times, that is two kilometres and that is no longer a sprint”.

    This was what Emil’s daily training looked liked in 1947:

    ’5x150m with 150m jogs between

    20x400m with 150m jogs between

    5x150m with 150m jogs between

    400m intervals run in 67-77 seconds (VO2 max pace)

    150m run very fast’

    Concluding statement:

    The science shows that the time required to train for endurance events is not as long as traditionally thought. Interval training is a great way to achieve the aerobic adaptations necesary for endurance performance, whilst reducing training volume. Interval training has also been shown to have superior health benefits when compared with cardio. Be warned though – interval training is tough and invovles working at a high intensity. For this reason, I would not advise untrained individuals to start with interval training, instead build up your aerobic base, with low intensity cardio exercise and after a sufficient amount of time introduce interval training to your workouts.

    Many thanks for reading!

    Follow on twitter (click the icon at the top of the page) and subscribe for weekly blogs!

    Tune in next week for your Science2Sport top up!

    Joe

     

    Category Health and Lifestyle, Performance and hypertrophy | Tags: | 3 Comments

  6. ‘The Female athlete – closing the gap?’

    May 7, 2012 by Joe Sumray

    The improvement in female running world records has increased faster than males between 1950 until the current time. This increased rate in performance begs the question as to whether or not the performance gap that exists between genders can be closed in years to come???

    There has been talk that women will run faster than men, particularly over longer endurance based events. However, this prediction appears to be inaccurate! Recent and more relevant findings show that endurance running world records are nearing their limit and consequently the gender difference of 8-14% over distances from 1500-42,000m  is unlikely to decrease further. Although these differences appear relatively small, in a review by Cheuvront et al (2005) it is highlighted that the models predict women will only break the 4-minute mile barrier in 2033 if at all, some 80 years after Roger Bannister.

    Reasons for differences in endurance performance are related to:

    - Differences in body composition & the higher fat content of women are almost certainly related to the performance differences  - however even when this is taken into account and data is expressed as lean body mass, differences still exist.

    - The critical component is the lower VO2 max (maximum oxygen uptake) observed in females – most probably arising from a lower haemoglobin content. VO2 max is thought to be the gold standard measure of cardio-respiratory fitness, with a large VO2 max being a pre-requisite for endurance athletes. Vo2 max is largely genetically determined, however it can be enhanced via training. For men (18-25) VO2 max values of 40-45 ml/kg/min are common, whilst in women values around 35-40ml/kg/min are more apparent. Cross-country skiers tend to have superhuman VO2 values of anything between 80-95 ml/kg/min being recorded!

    Sprinting too shows no indication that women can beat men! The current women’s 100m record stands at 10.48s compared to Usain Bolt’s lightning quick 9.78s (apologies for the awful pun).

    Reasons for differences in sprinting performance are related to:

    - The principle difference in sprint performance is due to differences in muscle cross sectional area which is almost certainly due to the anabolic effect of testosterone.

    - Males also have a greater percentage area occupied by type 11 fibres and this is likely to contribute to the greater ground forces exerted by men. Fibre type is largely genetically determined. Type 11 fibres are known as fast-twitch fibres, more suited to power and sprint type events, due to the fast rate of power generation. Type 1 fibres are known as slow-twitch fibres and are more suited to endurance events, due to their high aerobic capacity.  As the difference in fibre composition is largely due to fibre size and not number, it is unclear if sprint and strength-trained women would still show larger Type 1 fibres if compared to endurance-trained men. It is more likely that there is a continuum of fibre size reflecting the dominant usage.

    An interesting yet controversial point:

    It would appear evident that due to physiological differences between genders women will not ‘close the gap’ that exists. Men remain bigger, taller, stronger, faster and more powerful. However, Cheuvront et al (2005) speculate as to the future and propose that there still potentially remains one way in which women could reduce the performance gap and that is through the recent IOC medical commission recommendation which will allow athletes undergoing sexual re-assignment surgery to compete in their reassigned sex category whether re-assigned after or before puberty. The implication being that if the surgery occurs after puberty then these athletes could still have a significant advantage (i.e. more lean mass). Whether this inclusive policy is abused will be known only in the future!!! (athletes are extremely driven people, often putting their chosen disciplines before their health, will they go to the extremes of undergoing sexual re-assignment therapy in order to be at the top?)

    Reference:

    The Female Athlete (2009). The Olympic Textbook of Science and Sport, The Encyclopaedia of Sports Medicine An IOC Medical Commission Publication. Chapter 23 382 -397 Wiley- Blackwell , Chichester, UK

    Thank you for reading!

    Please subscribe and follow on twitter to receive your weekly dose of Science2Sport!

    Joe

     

     

     

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  7. My guide to growing your guns!

    May 1, 2012 by Joe Sumray

    Firstly, I would like to start with an apology for the lack of blogging action of late. I have been a rather busy boy!

    To make up for it I am going to provide you with my guide to bigger arms:

    1) Do not just train your arms!

    In order to achieve an impressive set of guns you need a workout routine that will add mass to your entire body. Your exercise routine should be based around compound exercises, such as squats, deadlifts, shrugs, pullups, barbell rows, bench press etc. Compound movements will increase the size and strength of your entire body.  A person that just performs bicep curls everyday of the week will not get anywhere. You would never build a house without the foundations in place, so how will your arms grow without a big back and  solid pair of legs!!!

    2) Do not ignore the triceps!

    A lot of beginners tend to concentrate solely on their biceps, leaving their triceps feeling neglected. The triceps make up a large proportion (~two thirds) of the arms and therefore need attention, in order to create a set of arms worthy of an Adonis. Good tricep exercises include; dips, close grip bench press, tricep extensions and dumbell kickbacks. Bare in mind your triceps do get worked when you are performing those compound movements, such as the bench press and military press.

    3) Keep good form and concentrate on the downward phase of the movement!

    Slow down! Everyone has encountered that person in the gym performing a set of barbell curls at lightning speed. These ‘cheats’ are getting no where! It is all about maintaining good form and keeping a nice steady pace, especially during the downward phase. During the downward phase of the bicep curl your biceps are working eccentrically. An eccentric contraction is when the muscle lengthens whilst under tension. It has been shown that the eccentric portion of the movement is the most important in terms of hypertrophy, as it is when the muscle is under the most tension. Therefore, make sure you count to at least 3 seconds when you are performing the downward phase of an exercise, such as the bicep curl.

    Extra tip – if you fancy changing up your workout a bit try performing ‘negative’ sets. Negatives concentrate on the downward phase of the movement. An example would be to complete the downward phase of  bicep curls or pullups very slowly (~6 seconds).     ‘Warning’  – your arms may feel like they are about to burst!

    4) Work your brachialis! 

    The brachialis is the little round muscle between your biceps and triceps. Whenever you do any bicep exercise you are going to work your brachialis to an extent. The reason you want to bare the brachialis in mind is because it sits under your biceps and a bigger brachialis helps your bicep peak higher whenever you flex them. Good exercises for your brachialis include: hammer curls, reverse curls and close grip pull-ups (overhand grip so your palms are facing away from you – opposite grip to what you would use to concentrate on your biceps).

    5) Chin-ups and Dips! 

    Close grip underhand chin ups are by far the best exercise for achieving bulging biceps. If you are not strong enough to do one chin up then most gyms have assisted machines that take a proportion of your body weight away, making the exercise easier to complete. Using the assisted machine you will gradually improve until you are able to perform the exercise without assistance! For the triceps you cant go wrong with dips!

    Concluding statement: 

    In order to gain a great set of arms you have to add mass to your entire body and start performing compound exercises such as squats, deadlifts and barbell rows. The triceps make up around 70% of your arms and should not be ignored. In addition, perform the eccentric phase of the movement slowly and controlled. Chin-ups and dips are great exercises for your biceps and triceps!

    Thanks for reading!

    Tune in next week to read about the ‘Female athlete – narrowing the gap?’

    Joe

     

     

    Category Performance and hypertrophy | Tags: | 3 Comments

  8. ‘Therapeutic use exemption’ and the ‘ADHD epidemic’

    April 9, 2012 by Joe Sumray

    If the medication an athlete is required to take to treat an illness or condition happens to fall under the prohibited list, a therapeutic use exemption (TUE) may give that athlete the authorization to take the needed medicine.

    A TUE will be granted only in accordance with the following criteria:

    1) The athlete would experience a significant impairment to health if the prohibited substance or method were to be withheld.

    2) The therapeutic use would produce no additional enhancement of performance other than that which might be anticipated by a return to a state of normal health.

    3) There is no reasonable therapeutic alternative to the use of the otherwise prohibited substance or method.

    Abuse of the TUE system?

    Methylphenidate (a form of Ritalin) is a drug used to treat attention deficit hyperactivity disorder (ADHD) and is on the prohibited list. Roelands et al (2008) found that subjects who took methylphenidate had an improved time trial performance in the heat, by 16% when compared with a placebo group.

    Among adults, the rate of diagnosis is between1 percent and 3.5 percent. But among pro baseball players, the disease seems epidemic! Soon after major league baseball banned amphetamines, the number of exemptions for ADHD drugs nearly quadrupled, so that in 2007 nearly 8% of all players had been ‘diagnosed’ with ADHD. How can ADHD multiply 4-fold  in a sport in a single year???

    A recent survey in college ice hockey found that 52% of players used stimulants, most commonly pseudoephedrine, ephedra, ritalin or amphetamines….

    Either an alarming epidemic of  ADHD  has sprung up, or athletes are seekeing ADHD drugs (e.g. Ritalin) to rev up for their sports!

    Science2Sport would love to hear your thoughts on this apparent ADHD epidemic within sport. Are the heightened number of diagnoses due to better exposure to medical care or is it blatent bending of the rules from athletes and their doctors? Does WADA (world anti-doping agency) need to crack down on the apparent abuse of the TUE system?

    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 find out how to add size to them biceps!

    Joe

     

    

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  9. ‘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.

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    Joe

     

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