MUSCLE. Report. Volume 7 Issue 12. The latest Scientific Discoveries in the Fields of Resistance Exercise, Nutrition and Supplementation.

Transcription

1 MUSCLE Report Volume 7 Issue 12 The latest Scientific Discoveries in the Fields of Resistance Exercise, Nutrition and Supplementation.

2 % CHANGE Muscle Report Volume 7 Issue 12 Big weights lead to stronger muscles but not bigger ones Many different variables go into designing an effective workout and the one most athletes focus on is the resistance they train with. The debate over the superiority of heavy versus lighter training has arguments for both sides but a recent meta-analysis helps clear up some of the confusion. The review consisted of 21 studies with the following inclusion criteria: All compared low load (<60% 1RM) with high load (>60% 1RM) training Training protocols consisted of sets performed to failure Measurements of strength and hypertrophy were included Each study involved a minimum of 6 weeks training Below are the results. Comparison of heavy vs. light loads RM strength Hypertrophy High load Low load The main finding from this review was that strength and hypertrophy adaptations appear to be independent of each other. High-load training was associated with greater strength increases compared to low loads (35.4% vs. 28.0%) but there was no noticeable difference in hypertrophy adaptations (8.3% vs. 7.0%). This suggests that if maximum strength is your goal then you should focus on heavier weights. If hypertrophy is your goal, then heavier and lighter loads are equally as effective. A major limitation with this result is that the majority of studies (18 out of 21) used untrained subjects. Of the 3 that used trained individuals the researchers found a trend for greater strength increases with high loads but there was insufficient data to form a conclusion. The researchers note this indicates higher training loads may become more important for strength increases in experienced athletes. Another limitation is that workout volume was not assessed. A study we discussed last year also found equivalent results from 12 weeks of high or low resistance training. The catch is the low resistance group performed 62% more volume to get the same results as the high resistance group. This is another factor that needs to be taken in to consideration when deciding whether to go heavy or not.

3 CHANGE (KG) PLASMA CONCENTRATION Muscle Report Volume 7 Issue 12 Your post-workout protein shake may not be as important as your think The post-workout protein shake is standard practice for athletes training for maximum muscle mass and strength. The idea is to get the amino acids into your body as soon as possible so they can be put to use repairing and remodelling damaged muscles. The gold standard in protein supplements is whey due to its high concentration of branched chain amino acids and the rapid rate its amino aids are absorbed. This makes whey protein a perfect choice postworkout. The downside to whey protein is that while its amino acids rapidly appear in the circulation they disappear just as quickly. Casein is another milk protein but releases amino acids much more slowly and over a longer period if time. Plasma amino acid appearance following whey and caseing ingestion TIME Whey Casein The above graph demonstrates both whey and casein have their advantages and disadvantages. What would happen if the two were taken in combination following a workout? This was the question asked by a group of French researchers who put 31 males with weight training experience through a 9-week training program. Participants trained 4 days per week using a periodized program of 3 x 3 week blocks. They were grouped into one of three supplement protocols; 100% whey, 50% whey/50% casein and 20% whey/80% casein. Below are the results Effect of protein type on changes after 9 weeks of training 0 Lean body mass Squat 3RM Bench Press 1RM 100% whey 50% whey 20% whey

4 As with all studies of this type there was a wide range of results among individuals. The above results are the averages for each group. As can be seen there is no significant difference between any of the supplement protocols (the 50% whey/casein blend appears to be associated with lower strength adaptations however this difference was not statistically significant). Given that whey protein is the gold standard in supplements it would be reasonable to expect this group to have the greater gains in strength and hypertrophy. This clearly did not happen. The question is why? This study at the very least questions the significance of the composition of post-workout protein shakes in contributing to strength and hypertrophy adaptations. Analysis of dietary intake during the training period revealed energy and protein intake was similar between groups. Protein intake averaged g/kg/day which falls within the recommendations of the American College of Sports Medicine and the International Society of Sports Nutrition (ISSN). Could overall protein intake have been the true driver of strength and hypertrophy adaptations and not the post-workout protein shake? It must be kept in mind the anabolic effect produced by a single workout can last for more than 24 hours. Ingesting 20g of whey protein immediately post-exercise will increase plasma amino acid levels for around 2.5 hours before returning to baseline. This represents around 10% of the time your muscles are sensitised to amino acid uptake and may explain why the composition of the post-workout shakes made no difference to the final results. This study suggests the type of post-workout protein makes little difference to strength and hypertrophy adaptations. This is supported by a similar study we discussed in our October 2016 issue where 68 males with weight training experience were put through 12 weeks of training. Immediately post-workout they consumed either a protein blend (whey/soy/casein), whey protein isolate or maltodextrin (a carbohydrate with no protein). All groups gained muscle mass with only a small benefit seen with the protein blend. Strength gains were equivalent between all supplement types. As with this present study dietary records revealed no significant differences in protein or energy intake between the three groups. This gives further support to the idea your post-workout protein shake has little effect on strength and hypertrophy adaptations and your diet is the true driver of long-term adaptations. We have been conditioned to associate a post-workout protein shake with enhanced strength and hypertrophy adaptations but the evidence shows any benefit is likely to be small. There is certainly no harm in having a protein shake immediately after your workout and the fact is you have to eat at some point. The lesson to take away is that post-workout protein supplements are not as critical as you think.

5 % CHANGE Muscle Report Volume 7 Issue 12 More is not always better The association between the branched-chain amino acid leucine and its role in stimulating muscle protein synthesis is well established. Logically it makes sense the more leucine contained in a protein the greater the increase in muscle protein synthesis. This may not be the case however. 24 males with weight training experience performed a heavy lower body workout and immediately afterwards and again at 2-hours post-workout consumed 20g of either whey protein isolate (WPI), whey protein concentrate (WPC) or milk. The study was a cross-over design so that all participants performed 3 workouts and consumed each of the 3 supplements following those workouts. Blood samples and muscle biopsies were taken to measure muscle protein synthesis and plasma amino acid concentrations over the 5-hour post-workout period. Below are the results for muscle protein synthesis rates at the 5-hour mark %Change in MPS 5-hours post-workout 0 WPI WPC Milk As can be seen there was no significant difference in muscle protein synthesis between the two whey protein types. WPI had a higher leucine content compared to either WPC or milk. This resulted in a higher concentration of leucine in the blood however this did not translate to a higher rate of muscle protein synthesis compared with WPC. This indicates that WPI and WPC both have sufficient quantities of branched-chain amino acids (in particular leucine) to maximally stimulate an increase in muscle protein synthesis following an intense bout of resistance exercise. The reduced rates of muscle protein synthesis with the milk can be attributed to milk being composed of 80% casein and 20% whey. The slower rate of digestion of the milk was evident in the lower rate of amino acids appearing in the blood. These results indicate that as far as increasing muscle protein synthesis is concerned, WPI and WPC are equally as effective. It also demonstrates that higher concentrations of leucine in a protein supplement do not make it more effective at optimising the post-workout anabolic response.

6 Are BCAA s more hype than help? Branched chain amino acids (BCAA s) are heavily promoted for their ability to stimulate muscle protein synthesis. Given that there are 20 amino acids that make up proteins yet only 3 of them are BCAA s it is quite amazing that they alone offer such a powerful anabolic stimulus. So entrenched has the association between BCAA s and their anabolic potential no one questions whether they truly live up to the claims. A recent review published in the Journal of the International Society of Sports Nutrition has done just that and the conclusions challenge accepted wisdom. The anabolic effect from BCAA s comes down to their ability to stimulate pathways in the body that trigger muscle protein synthesis. The authors point out however that for muscle protein synthesis to increase the body needs to have an adequate supply of all 20 amino acids, not just BCAA s. They cite two studies that showed infusion of BCAA s over periods of 3 or 16 hours actually resulted in muscle protein synthesis decreasing by up to 43%! This suggests in the absence of the other 17 amino acids BCAA s may actually be catabolic. Of the 3 BCAA s leucine is one that receives the most attention. The authors point out that while supplementing with leucine alone stimulates anabolic pathways it also triggers the metabolic pathways that oxidise all the BCAA s. As a result, supplementing with leucine will hasten the removal of the other BCAA s (isoleucine and valine) from the circulation. They argue this is may be why long-term studies on leucine supplementation have failed to produce positive results. The argument that BCAA s do not promote an anabolic environment is premised on research that used BCAA s alone. This is a significant limitation with the conclusions of this review. Only one study is discussed where BCAA s were used in conjunction with a protein source. This study found 5g of leucine added to 6.25g of whey protein increased muscle protein synthesis to a level equivalent to that seen with 25g of whey protein alone (we discussed this study in our February 2014 issue). The authors acknowledge that BCAA s taken in conjunction with protein is a different matter altogether and one they do not cover. So what are we to make of this? Do BCAA s promote an anabolic environment or not? The answer is it depends. By themselves, no they do not. In the presence of an adequate supply of amino acids, yes they do. This conclusion raises the question of whether there is any advantage in supplementing with BCAA s. Whenever you consume protein, especially whey protein, you are also taking in BCAA s, so do you really need additional BCAA s? This is a question yet to be addressed. In their latest position stand on protein and exercise the International Society of Sports Nutrition acknowledges the role of BCAA s in muscle protein synthesis but no mention is made of supplementing with them. Based on this evidence it is difficult to justify BCAA supplementation if you are consuming sufficient amounts of high quality protein throughout the day.

7 Then again If you are now questioning wether or not BCAA s are of any use you are about to get a whole lot more confused. A recent study published in the Journal of Sports Medicine and Physical Fitness had 165 males perform 30 eccentric biceps curls with their non-dominant arm. One group was given a placebo before and after the exercise (control group), another was given 9.6g of BCAA s before and a placebo after, another was given a placebo before and the same dose of BCAA s after. Various measures of muscle damage, subjective measures of delayed onset muscle soreness (DOMS) and recovery were taken before, immediately after and for 4 days post-exercise. Compared to the control group it was found those who took BCAA s before training reported lower ratings of DOMS, the increase in arm circumference was lower (indicating reduced inflammation) and they demonstrated an increased range of motion in the trained arm. Creatine kinase, lactate dehydrogenase and aldolase were also significantly lower with preexercise BCAA s. Taken together these results indicate BCAA s taken prior to a bout of muscle damaging exercise attenuates the level of damage. Those who took BCAA s after training also demonstrated lower levels of muscle damage compared to the control group however it was greater than when BCAA s were taken pre-exercise. This study suggests pre-workout BCAA supplementation does have positive physiological effects. It must be remembered however this is only an acute effect. It is wrong to assume this short-term benefit would automatically translate into long-term benefits for strength and hypertrophy adaptations. Another limitation is that this study did not assess muscle performance. We assume reduced muscle damage means greater exercise performance in subsequent days however this cannot be stated from these results alone. A 2012 study reported 20g of BCAA s taken before and after 5 sets of 20 drop jumps resulted in reduced markers of muscle damage compared to a placebo. When vertical jump height was tested at 24, 48 and 96-hours post-exercise there was no difference in performance recovery between the supplement and control groups. This suggests the markers we use to establish muscle damage do not necessarily correlate with the structural and contractile properties of the damaged muscles. You may have less muscle soreness if you take BCAA s but if your muscles are not going to perform any better in your next workout is there really any point taking them? Perhaps the biggest limitation of all the research into BCAA supplementation is that despite the positive short-term effects there is a lack of research looking at at the long-term effects. This is significant because at the end of the day that is why athletes take supplements; they want to maximise the results from their training. Without these long-term studies it is difficult to justify the use of BCAA s for maximising strength and hypertrophy adaptations.

8 % CHANGE Muscle Report Volume 7 Issue 12 Might be best to avoid this ingredient Taurine is a compound found in most mammalian tissues. You may be familiar with it as an ingredient in many energy drinks but it also plays a critical role in many physiological functions in the human body. It is typically described as an amino acid (which is not technically correct) however it plays no role in muscle protein synthesis, so its role in the body is strictly functional. Taurine has been shown to have antioxidant properties and increase aerobic exercise capacity. It has also been shown to enhance recovery from resistance exercise. This sound all positive but new research suggest there may be one big downside. The study involved 14 male athletes who were grouped into either caffeine users or noncaffeine users. On separate occasions they performed leg extensions on a dynamometer. The leg extensions consisted of 4 isokinetic repetitions (where the speed of muscle contraction is constant throughout the range of motion) and 3 isometric repetitions (a static contraction where the length of the muscle does not change). The protocol was performed with and without taurine supplementation. The results are not what you would expect. 10 Effect of taurine on muscle power Maximum isokinetic power Caffeine users Maximum isometric power Non-caffeine users For the non-caffeine users, taurine supplementation actually resulted in a decrease in the maximum amount of power that could be generated (maximum power was determined from testing prior to the intervention). For the caffeine users, taurine supplementation resulted in an increase in isokinetic power but no change to isometric power. This occurred despite caffeine not being used by either group prior to the performance. These results suggest a single dose of taurine prior to resistance exercise has the potential to decrease performance by impairing muscle contractions. Interestingly this result only seems to only apply to those who abstain from caffeine. For caffeine users, taurine may have the opposite effect and increase isokinetic power. Why this occurred is anyone s guess and there does not appear to be any research with similar results. The logical conclusion to draw from this result is that taurine interferes with the ability of muscle fibres to contract. The problem with this argument is that supplementing with taurine does not increase taurine content of the muscles. If the result of this latest study is true and not some statistical anomaly, then the mechanism of action must be from outside the muscle.

9 One for the animal lovers Weight training athletes all love animals. We mostly love them medium rare with a baked potato on the side. Some athletes however prefer their animals to be grazing in a field somewhere happily living their lives. This later category of athlete is certainly not the norm in weight training circles but with the growing interest in meat-free diets (dare we use the v word; vegan?) the International Society of Sports Nutrition has published a paper on this very topic. If this subject is of no interest to you then feel free to skip this summary, otherwise read on. The paper is directed at athletes in general but the issues raised do apply to those training for strength and hypertrophy. The main areas of concern for athletes following a vegan diet are: Energy If you are trying to gain weight, then a positive energy balance is critical. An energy deficit during periods of intense training can lead to compromised immunity, loss of muscle mass, reduced strength, lower work capacity and impaired training adaptations. Vegan diets are generally lower in energy compared to omnivorous diets. The reduced energy comes from lower intakes of protein and fat which may be attributed to the high fibre content of plant foods resulting in less food being consumed. The recommendations are to increase the frequency of food intake and increase the consumption of energy dense foods such as seeds, nuts and oils. Protein Apart from not consuming enough protein on a vegan diet the quality of protein is also lower. Plant proteins are often incomplete, lacking certain essential amino acids. This means an athlete on a vegan diet needs to consume a wide variety of different foods such as grains, legumes, nuts and seeds. These foods do not have to be consumed in the same meal but should be spread throughout the day. Plant-based protein supplements can help athletes meet their daily protein needs. Due to the lower digestibility of plant proteins it is recommended athletes aim for around 2.0g/kg/day. Fat Vegan diets are typically low fat. Apart from the reduced energy associated with a low fat diet, a question mark remains over the possible implications for hormones and athletic performance. Adequate intake of oils, avocados, nuts and seeds should reduce any deleterious effects. Vitamin B12 The primary source of B12 is meat, eggs and dairy so vegans and vegetarians are at an increased risk of developing a B12 deficiency. A deficiency in this micronutrient can lead to

10 anaemia, neurological symptoms and nerve damage. These last two symptoms can be permanent with long-term deficiency. Fortified foods and supplements are essential for those avoiding animal products. Iron Iron deficiency can result in anaemia, reducing exercise capacity and possibly even adaptations to training. Plant foods contain iron but they also contain inhibitors that can impair iron absorption. Research on populations suggest females following a vegan diet may be at greater risk of iron deficiency compared to males however as a general rule iron deficiency does not appear to be widespread among vegetarians and vegans. Iron absorption can be enhanced by consuming vitamin C alongside iron-containing plant foods and avoiding absorption inhibitors such as tea, coffee and cocoa. Zinc Zinc is required for enzymes, DNA, cell repair and growth and protein metabolism. Plants contain zinc but bioavailability is lower than with animal foods. The Institute of Medicine suggests those who do not consume animal products may need to consume 50% more zinc due to this lower bioavailability. The human body appears to be able to adapt to a lower zinc intake without clinical symptoms presenting vegans and vegetarians still need to include zincrich foods such as seeds, grains, nuts and beans. Bioavailability can be enhanced by soaking, sprouting and fermenting foods prior to eating. Creatine We all familiar with the creatine supplements but we also obtain it in our diet through eating meat. Those who abstain from eating meat have been shown to have lower creatine stores. The ergogenic benefits of creatine supplementation are well known and research suggests those with the lowest creatine stores may get the biggest performance benefit. There a number of other nutrients covered in the ISSN review but this gives you some idea how a meat-free diet may impact the results you get from all your hard work in the gym. In no way is this meant to encourage or discourage anyone from following a vegetarian or vegan diet but if you do it is important to be aware of the potential downsides. If you are thinking about following such a diet it would be a good idea to consult a dietician so they can put you on the right track.

11 Losing weight, the right way There is a wealth of case studies looking at the effects of contest preparation on male bodybuilders. The bad news is that the results consistently show that along with the reduction in body fat there is a corresponding reduction in muscle mass. As an example a 2015 study reported that during 14 weeks of pre-contest preparation the athlete under investigation lost 6.7kg of fat and 5.0kg of muscle. When almost half the weight you lose is lean body mass that is not a good thing when you are supposed to be body building! One of key reasons for the loss of so much lean mass is the reduced energy intake. Your body needs energy to function properly, not to mention to power through workouts. If your body is not getting the energy it needs from your diet then it has to rely on the energy stored in fat and muscle. In a perfect world you body would get its energy solely from fat but this is simply not the case. Is it an inevitable consequence of shedding fat you will lose an almost equivalent amount of muscle? A new case study suggests the answer is no. This latest study followed a 29-year old female during a 32-week figure contest preparation. Over that period the athlete lost 8.0kg of body fat but gained 0.7kg of muscle! So how did she do it? It is not possible to compare the present study with the earlier one but there are a couple of striking differences which may account for the different results. Firstly, the latest study involved a 32-week preparation period compared to 14 weeks with the earlier one. The implication for this is that the male bodybuilder lost an average 1.0% of his starting body mass per week over the 14 weeks while the female figure competitor lost an average 0.5% of her starting body mass per week over 32 weeks. This slower rate of weight loss reflects a smaller energy deficit and may have had a muscle-sparing effect. Secondly, the male bodybuilder had a daily protein intake around 2.4g/kg (45% of total energy intake) while the female athlete consumed as much as 3.5g/kg (55% if total energy intake). This additional protein may also have spared muscle tissue from catabolism. In their Evidence-Based Recommendations for Natural Bodybuilding Contest Preparation the International Society of Sports Nutrition recommends bodybuilders consume g/kg of protein to help retain muscle mass during periods of energy deficit. The reduced energy intake required to reduce body fat comes at a cost: your hard earned muscle. Avoiding drastic calorie deficits and reducing your energy intake slowly over a longer period of time coupled with a significantly increased protein intake may help reduce the catabolic effects of dieting.

12 References Big weights lead to stronger muscles but not bigger ones Schoenfeld, BJ, Grgic, J, Osborn, D, Krieger, JW. Strength and hypertrophy adaptations between low- versus high-load resistance training: A systematic review and meta-analysis. Journal of Strength and Conditioning Research. Published online 22 August Your post-workout protein shake may not be as important as your think Fabre, M, Hausswirth, C, Tioller, E, Molle, O, Louis, J, Durguerian, A, Neveux, N, Bigard, X. Effects of Postexercise Protein Intake on Muscle Mass and Strength During Resistance Training: Is There an Optimal Ratio Between Fast and Slow Proteins? International Journal of Sports Nutrition and Exercise Metabolism (5): More is not always better Hamarsland, H, Nordengen, AL, Aas, SN, Holte, K, Garthe, I, Paulsen, G, Cotter, M, Borsheim, E, Benestad, HB, Raastad, T. Native whey protein with high levels of leucine results I similar post-exercise muscular anabolic responses as regular whey protein: a randomized controlled trial. Journal of the International Society of Sports Nutrition. Published online 21 November Are BCAA s more hype than help? Wolfe, RR. Branched chain amino acids and muscle protein synthesis in humans: myth or reality? Journal of the International Society of Sports Nutrition :30. Then again Ra, S, Miyazaki, T, Kojima, R, Komine, S, Ishikura, K, Kawanaka, K, Honda, A, Matsuzaki, Y, Ohmori, H. Effect of BCAA supplement timing on exercise-induced muscle soreness and damage: a pilot placebo-controlled double-blind study. Journal of Sports Medicine and Physical Fitness. Published online 22 September Might be best to avoid this ingredient Lim, ZX, Singh, A, Leow, ZX, Arthur, PG, Fournier, PA. The effect of acute taurine ingestion on human maximal voluntary muscle contraction. Medicine & Science in Sports & Exercise. Published online 22 September One for the animal lovers Rogerson, D. Vegan diets: practical advice for athletes and exercisers. Journal of the International Society of Sports Nutrition.

13 Losing weight, the right way Petrizzo, J, DiMenna, FJ, Martins, K, Wygand, J, Otto, RM. Case Study: The Effect of 32 Weeks of Figure-Contest Preparation on a Self-Proclaimed Drug-Free Female s Lean Body and Bone Mass. International Journal of Sports Nutrition and Exercise Metabolism (6):