My name is Nick and I am currently doing my PhD in physiology with an emphasis in muscle physiology. Welcome to my exercise science blog. Unlike a lot of fitness blogs out there, this one is unique because it is backed by true science. You will find only articles that have been peer reviewed and published in top tier science journals on this blog. For the fast easy read, just read the bold type. If you have any questions do not hesitate to ask me. I am at your disposition for any advice in exercise or just basic physiology. This is not a progress blog to benefit myself but rather to share some of my knowledge and expertise with you that I have gained over my years dedicating my career to exercise science. If I do not know the answer, I will do my best to search through the journals to find it for you. Although I am in biomedical research, I am not a licensed medical professional so please consult a physician before entering any exercise or nutrition program.
Taking ice baths post-exercise seems to be the most popular method of reducing delayed onset muscle soreness for novice and elite athletes. This method, known scientifically as cryotherapy, is growing to be more popular than traditional ones such as massage, stretching, or taking non-steroidal anti-inflammatory drugs (NSAIDs). The most popular forms of cryotherapy are cycling 1 min in ice water (5 degrees Celsius) followed by 1 minute out for a total of three times or a longer duration of 15 minutes at 15 degrees Celsius. Now that you have the background, I’ve went out and found an enormous extensive review on the subject to make clear whether or not this technique is useful or useless at combating muscle soreness and aiding recovery.
The scientific claims: You know that you treat sprains, strains, or any swelling in the body with ice. The mechanisms for why cryotherapy works are similar; reduce pain, swelling, and inflammation. There is also vasoconstriction (decreasing the diameter of the blood vessel) which stimulates blood flow and nutrient and waste transfer as well as decrease in nerve transmission speed, which could alter the threshold of pain receptors.
The studies used: The review included 17 small trials (published from 1998-2009) of 366 participants. No restrictions were placed on age (16-29), gender female, or type of level of exercise. Also, no restrictions were placed on duration or frequency of immersions or depth of immersion. The studies were all of small sample size (20 participants or less) except for one that used 54.
The exercises used: All exercise used were designed to produce delayed onset muscle soreness (DOMS) under laboratory controlled conditions. Repetitions for resistance exercise ranged from 50-100 of eccentric or alternative concentric and eccentric contractions. The other studies used running or cycling in single bout efforts (for the bike) or steady state efforts. Few actually included team sport exercise (basketball and soccer).
The cryotherapy used: The most common for the studies was 10-15 degrees Celsius with an average immersion of 12.6 minutes. This was employed in almost all of the studies immediately after exercise. The different methods of cold-water immersion were compared to nothing/rest (the most common), cold-water immersion vs. contrast immersion (switching between hot and cold), cold-water immersion vs. warm water, and cold-water immersion vs. active recovery.
Enough with the technicalities. Let’s go to the results.
Cold-water immersion vs. nothing: In terms of muscle soreness, there is no significant difference immediately between the two conditions but at 24, 49, 72, 96 hours later the cold-immersion group reported a significantly lower amount of muscle soreness than the group that just rested. This effect seems to be more prevalent after running based exercises than resistance exercises but the authors not that due to the various types of exercises that were performed between all the studies, plus the sample sizes being small, it is difficult to find whether or not this is truly significant. There were no significant differences in strength, power, functional performance, swelling, or biomarkers of muscle damage.
Cold-water immersion vs. contrast immersion: In terms of muscle soreness, there was no significant differences between the groups. Also, there was no significant differences in strength, power, functional performance (time to fatigue), swelling, range of movement, or biomarkers of muscle damage.
Cold-water immersion vs. warm-water immersion: There was significant lower levels of muscle soreness reported only for the cold-water immersion group at time-point 96 hours with no differences in strength, power, functional performance, swelling, or biomarkers of muscle damage.
Cold-water immersion vs. active recovery: There are no significant differences in reports of muscle soreness, strength, power, functional performance, swelling, or biomarkers of muscle damage.
Discussion/Conclusions: Cold-water immersion did significantly reduce muscle soreness at time points 24, 48, 72, and 96 hours post-exercise. However, it is important to note that these were all subjective reporting (self-reports) and the authors state it is hard to draw true conclusions from the data due to poor methodological quality. There were high risks of bias due to the fact that blinding was performed poorly as well as concealment of group assignments (only 1 study did this effectively). There were also large differences in the types of exercises used and subjects were a mix between trained and untrained. The effectiveness very well may rely on the specificity of the exercise performed as well as the athletic level of the individual.
My input: Did you know that in the 1920s, cyclists in the Tour de France would smoke during the race because they believed that smoking opened up the blood vessels and oxygen transport machinery of the lungs? Ridiculous, right? I’m not saying ice-baths are as crazy as this, but are they truly beneficial to aid recovery in the muscle? I’m not so sure. From the most basic laws of chemistry, we know that when something is heated up the molecules in it move faster and when something is cooled down the molecules in it slow down. If you are exposing your muscles to cold, all of the molecular processes will slow down. You need enzymes (which function effectively at specific temperatures) and proteins moving post-exercise to begin the repair process and signal inflammation, and if you’ve read my previous posts on muscle hypertrophy, you know inflammation is necessary. It is the same reasoning to avoid NSAIDs in hopes of reducing muscle soreness. For this reason, I’m always heading for the exact opposite after training, a hot shower. The reason I do this is not only to continue normal biochemical processes in the muscle but also to incorporate the activation of what are called heat shock proteins. Heat shock proteins are proteins in the body that respond to stress or elevated temperatures. They function as chaperones for other proteins by aiding them to conform to a certain shape and stabilize proteins that are not shaped properly. Basically, they can clean up the mess inside of the muscle cell and help with repair. This is another reason why I’m not on the ice-bath bandwagon. You might feel that it has helped you before in the past and it possibly could have helped, but I just want to let you know there is no scientific evidence supporting it. The studies are low quality studies. If you truly want a good study on this, take a group of at least 35 people, train their legs or their arms simultaneously with the same protocol and put one limb in the ice and one limb not in the ice or in warm water, take muscle biopsies, and see the differences between the conditions (Anyone want to take this on as a nice Master’s or PhD project? I’ll be glad to give advice for it). To my knowledge this has not been done and this would be the best way to see if cold-immersion truly helps. Although there was some evidence in a decrease in self-reported muscle soreness, I’m still not convinced and higher quality studies are necessary before I’ll be convinced.
The Phillips group is back at it again with another great muscle paper that just came out about hypertrophy (gaining muscle mass). It is not nutrition oriented this time, but instead discusses the amount of weight necessary to stimulate an increase in muscle size.
Introduction: It has been shown that under an acute exercise bout, using 30% of a person’s 1 rep max (1RM) to the point of muscle fatigue (failure) was equally as effective at stimulating muscle protein synthesis in the muscle fibers as that of loads lifted at 90% of 1RM (also lifted to failure). This was shown previously by this same group. Even more intriguing, they found the 30%-1RM condition resulted in a more prolonged muscle protein synthetic response with a greater rise in muscle protein synthesis than the 90% 1RM group 24 hours post-exercise. Furthermore, other than a relative training load (weight), another important variable for resistance training is volume or the amount of work performed. The Phillips group also showed before that 3 sets at 70% of 1RM to failure led to greater and a more prolonged muscle protein synthetic rate in the fibers as compared to a single set condition. However, as I stated, these are all under short-term conditions. Thus, this new study wishes to see if these hold true under long-term conditions.
Methods: Eighteen healthy young men underwent 10 weeks of one leg knee extension resistance training where each leg was randomly assigned to one of the three training conditions: 1 set performed to voluntary failure at 80% of 1RM (80%-1), 3 sets performed to the point of fatigue at 80% of 1RM (80%-3), or 3 sets performed to the point of fatigue at 30% of 1RM (30%-3).
Results: After 10 weeks of training, quadriceps muscle volume increased significantly in all groups and average type I and type II muscle fiber area increased with training (irrespective of training condition with no significant differences between groups). All three groups also increased their 1RM but it was increased greatest in the 80%-1 & 80%-3 groups. Total work that could be completed with 80% of the subect’s 1RM increased in all groups and the number of reps that could be performed with 80% of their current 1RM increased in all groups.
Discussion: The main outcome from this paper is that there was no difference in the magnitude of quadriceps muscle hypertrophy (determined by MRI and muscle fiber area) between legs trained at 30% or 80% of 1RM after 10 weeks of knee-extensor exercise. Furthermore, there was no statistical difference in the degree of hypertrophy between the 80%-1 and 80%-3 group even though the 3 set group gained a little more volume than the 1 set group. More interestingly, the 80%-3 and 30%-3 showed more than double the average hypertrophy of the 80%-1 condition. This adds to the mounting evidence that lifting lighter loads, so long as fatigue is induced, induces roughly equal hypertrophy gains. It is important to note that both type I and type II fibers increased equally between the heavy and light loads meaning that both fiber types were recruited during the training to an almost equal amount.
My input: I can’t preach it enough or put it in bold enough; fatigue, fatigue, fatigue. Train your muscles till failure. Don’t worry about the weight on the bar or saving yourself for that last all out set. Take every set to muscle failure, even beyond with partial repetitions and forced repetitions (if you have a spotter). I have written it in the past but it needs reemphasized; when training for hypertrophy, the muscle does not “know” the weight on the bar, all it knows is fatigue. Check your ego, men. Women too, who use 5 lb dumbbells and do unlimited numbers of reps (you know who you are), aren’t accomplishing anything. I think it is also important to mention that this study pushes for a volume principle whereas the two groups that completed 3 sets instead of 1 had more muscle volume after the 10 weeks than the group that did only 1 set till failure. The next plausible step is to see if there is in fact a threshold where doing more sets than 3 will lead to an even greater increase in muscle size (future PhD thesis for anyone that wants to take it). I would also like to see this study repeated with subjects that are weight trained to eliminate the possibility of a first-time adaptive response to training (another future PhD thesis for anyone that wants to take it). That could have been the reason why the 1 set to failure condition saw an increase in muscle hypertrophy due to the fact they have not weight trained in over a year. On the strength side, it also lends to credence to specificity of training in that the leg conditions that used 80% of their 1RM increased their strength more than the group that used only 30%. If you want to solely increase your strength, focus on using heavier weight, duh. More long-term studies are needed because a lot of questions can still be asked, but this is already off to a great start when looking at chronic resistance training responses in muscle.
"The last three or four reps is what makes the muscle grow. This area of pain divides the champion from someone else who is not a champion. That’s what most people lack, having the guts to go on and just say they’ll go through the pain no matter what happens."
Whey protein or leucine post-workout to increase muscle protein synthesis (MPS)? The Phillips group just published an article trying to answer this question.
Introduction: You all are probably aware that ingesting amino acids stimulates an increase in muscle protein synthesis even without resistance training. Leucine has been toted to best stimulate MPS by activating components of a signalling cascade known as mTOR. There is still controversy though as to whether or not leucine can enhance MPS following leucine infusion or by simply adding more of it to a post-workout protein drink. This group previously reported the the optimal dose of protein post-workout to stimulate MPS was 20g and that anything below this is not sufficient and anything above this number (40g) does not increase MPS further. Therefore, the aim of this study was to see if taking a “sub-optimal” dose of whey (6.25g with approximately 0.75g of leucine) protein and supplementing it with leucine or a mixture of essential amino acids without leucine would have an effect on MPS at rest and after acute resistance training. This will be compared to a dose of whey (25g with approximately 3.0g of leucine) which is sufficient to induce maximal stimulation of MPS after resistance exercise.
Methods: Twenty-four adult males were randomized to one of three groups that either ingested a whey protein drink, a leucine drink, or an essential amino acid drink. Prior to ingestion, the volunteers completed an acute bout of unilateral resistance exercise (knee extensions). Muscle biopsies were taken at the time of ingestion and at time points 1 hour, 3 hours, and 5 hours post-exercise.
Results: After whey protein ingestion, blood leucine, branch-chain amino acids, essential amino acids, and total amino acids were all highest as compared to the groups that ingested leucine or EAA (without leucine). Blood leucine was only higher initially after ingesting the leucine drink but stayed elevated longer by ingesting whey. Rates of MPS remained increased for 3-5 hours at exercise recovery above those volunteers who did not ingest anything, versus the groups who ingested leucine or the EAA drink.
Discussion: A dose of whey protein that has been previously shown to be less than maximally effective to stimulate MPS after resistance exercise, when supplemented with leucine, resulted in an early (1-3 hour post-exercise recovery) increase in rates of MPS equal to that of ingesting 25g of whey. Also, the same was found by supplementing a low dose of whey with essential amino acids void of leucine. However, MPS was sustained longer (3-5 hours post-exercise) only with the group that ingested whey protein. These differences occurred despite the fact that blood amino acid levels returned to baseline after 3-5 hours but MPS still continued. Therefore, the authors state that peak activation of MPS does not appear to be driven by increasing leucine in the blood and that amino acid transport across the sarcolemma (plasma membrance of the muscle cell) and intracellular amino acid availability may be important in the regulation of MPS.
Conclusion: Leucine stimulates MPS post-exercise equal to that of whey protein, despite only containing 45% of the total EAA content of the whey. However, similar increases in MPS were observed in the EAA ingestion group that did not contain leucine. Thus, the authors speculate that in young healthy individuals, the leucine content provided by approximately 6.25g (approximately 0.75g of leucine) of whey protein seems adequate to maximally stimulate MPS if sufficient amounts if the other EAA are provided (approximately 8.5g EAA). Also, the whey protein ingestion group was the only group that sustained MPS 3-5 hours post-exercise.
My input/practicality: What if I were to tell you I can make a 1lb bag of whey protein last me 3 months? Well I can, and I do, and I’ve been doing it for years. I only use a half scoop of whey protein post-exercise. Never a full scoop. Never a “heaping” scoop. Why do you even think they use the word heaping? It’s all about the dolla dolla bill y’all. This study shows that only 6.25g of whey is necessary to maximally stimulate protein synthesis as long as it contains approximately 750mg of leucine and 8.5g of the other 8 essential amino acids (which are histidine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine). Make sure you check on the labels of your favorite whey protein because it usually lists the amount of leucine and the other essential amino acids on it. One scoop of whey is usually on average around 20g of protein so if you use a half scoop like me it is around 10g (still a little over from what this study suggests). Supplement companies are going to hate this study (like they read them anyways) as well as me for posting this but you’ll love it/me for saving you money.
Here is what a gene microarray looks like. In this image, there are 824 genes that were scanned during resistance exercise; in this case, bicep curls. The red are higher levels of mRNA and the green are lower levels. It’s amazing, although sometimes quite messy in this case, what we can now do in science.
What this group found is that resistance training blunts genes involved in immune responses by minimizing expression of genes involved in the recruitment of immune cells while simultaneously upregulating genes responsible for inflammation.
In addition, resistance training blunted genes involved in glucose metabolism, mitochondrial structure, and oxidative phosphorylation. This makes sense due to the specificity of the training. Resistance training would not require the upregulation of genes involved in these processes because it is not an endurance type activity. For this reason, I always recommend trying to separate sessions in the gym of weight training and cardio as much as possible because they clearly upregulate and downregulate different genes. It may be detrimental to the specific adaptive training response if both are done around a similar period, but this is yet to be shown to my knowledge. Some studies were published on this but I would still say it’s just merely a working hypothesis for now.
What I’m not going to do this time is present any articles but I just would like to take a few minutes to address weight training for hypertrophy and or definition. If you are a powerlifter/strength athlete, this probably doesn’t apply to you but for those interested in weight training for gains or tone, read on. First, I would like to discuss a common phrase that bothers me. Muscle confusion. There is no such thing as muscle “confusion”. There, I said it. Muscles are not comprised of neurons, just innervated by them; thus, they cannot “think”. Second, another common phrase tossed around, the “muscle does not know how much weight is on the bar,” false. You are probably thinking I just contradicted myself so let me explain. The muscle very well knows how much weight is on the bar but this is due to innervation from efferent and afferent neurons through the spinal cord. Think of it as a reflex if you will. The definition of a reflex is basic physiology is a quantitative invariant response to a specific stimulus. Key words, a specific stimulus. The more stimuli you have on the muscle, the more motor units (the contractile units of the muscle) you need activated, by the spinal cord, to lift the weight. Therefore, the muscle does know how much weight is on the bar because the central nervous system is telling it how to operate. So what am I getting at? Even though the muscle “knows”, with the help of the CNS, how much weight is on the bar, you do NOT need heavy weight to activate muscle to drive growth and definition. Instead of going to the gym and trying to lift as much weight as possible, instead, drop the weight 10lbs and focus on slow controlled contractions. This is an efficient stimulus in itself of activating muscle fibers of various types necessary for complete definition and growth. You can’t “confuse” the muscle because a stimulus is still there regardless. I’m not advocating not going heavy ever, but I urge you to try this for a couple of months and see how much harder it is than throwing around heavier weight for 1 second concentric and 1 second eccentric rep schemes.
Just a note: Times in the lab have been hectic the past 2 weeks, 12 hour workdays of taking images of skeletal muscle in the basement of the electron microscopy platform, so I have had not the time to read articles as much as I would like or answer your questions. This Saturday, I leave for vacation for 2 weeks but I promise you I will get to the many questions I have in my ask box over that time period. Thank you for your continued support.
So you’re sore and you want to know what is going on in your muscle. Why? Don’t you just love being sore?
Introduction: Changes in muscle function after exercise training as well as the infamous DOMS (delayed onset muscle soreness) are collectively referred to as exercise-induced muscle damage (EIMD). These changes can be brought upon my enzymes, inflammatory markers, and/or glycogen stores inside of the muscle, which in turn will alter your time to fatigue and eventually your ability to perform the next time you exercise. One of the most damaging training methods is eccentric training, or as we know the negative portion of a rep. Therefore, this study induced eccentric exercise to discover changes in muscle metabolism.
Hypothesis: EIMD alters the muscle metabolic response to dynamic exercise and thus contributes to reduced exercise tolerance in humans.
Results: There were changes in all markers of muscle damage following eccentric exercise. Muscle pH levels were lower, and the concentration of inorganic phosphate (measured by 31P-MRS) increased as well as the ratio of inorganic phosphate to phosphocreatine. Time to exhaustion and peak work rates were decreased following eccentric exercise.
Conclusion: This study is the first of its kind to use MRI techniques to evaluate changes in muscle metabolism following an EMID protocol. This finding of a decrease in time to exhaustion is not linked towards a lower muscle pH or lower levels of phosphocreatine, but researchers believe it is due to higher levels of circulating inorganic phosphates. Increases in intracellular [Pi] can inhibit force production via direct action on cross-bridge formation or on other sites in the excitation contraction pathway and may play a key role in the development of muscle fatigue.
My input: So you’re probably thinking, so what? We know that we are sore after exercise and we know that we cannot have optimal performances the next time because of this soreness. I say to you, correct, but I also say to you that this is novel because of this being linked to circulating levels of this inorganic phosphate even during rest before exercise was initiated. Therefore, those that think it is solely due to a decreased pH that causes soreness and a decreased performance may be slightly mistrued.
Practicality: I just wanted to note that the training protocol used here to induce muscle damage was that of German Volume Training. That is 10 sets of 10 reps, which in this case, 10 sets of 10 reps for the squat. Thus, those that are training high volume in the gym should give themselves >48 hours rest before training that body group again because this was the time-frame used in between testing for the subjects.
Dr. Jim Stoppani, the senior science editor for FLEX and Muscle & Fitness magazines, provides a short video on the benefits of supplementing with creatine.
Note: Dr. Stoppani is not sponsored by any supplement company. Here is a link to the supplements he recommends from different manufacturers for different goals.
Jim Stoppani holds a doctorate in exercise physiology with a minor in biochemistry from the University of Connecticut. Soon after graduation, he served as a postdoctoral research fellow in the prestigious John B. Pierce Laboratory and Department of Cellular and Molecular Physiology at Yale University School of Medicine. This is the time when Jim started to investigate the effects of diet and exercise on gene regulation in muscle tissue. Following his research, he was given the “Gatorade Beginning Investigator in Exercise Science” Award in 2002 by the American Physiological Society.
Ingesting CHO alone or in combination with PRO during resistance exercise increases muscle glycogen, offsets muscle damage and facilitates greater training adaptations after either acute or prolonged periods of supplementation with resistance training.
The post-exercise ingestion (immediately to 3 hours post) of amino acids, primarily essential amino acids, has been shown to stimulate robust increases in muscle protein synthesis, while the addition of CHO may stimulate even greater levels of protein synthesis. Additionally, pre-exercise consumption of a CHO + PRO supplement may result in peak levels of protein synthesis.
During consistent, prolonged resistance training, post-exercise consumption of varying doses of CHO + PRO supplements in varying dosages have been shown to stimulate improvements in strength and body composition when compared to control or placebo conditions
The addition of creatine (Cr) (0.1 g Cr/kg/day) to a CHO + PRO supplement may facilitate even greater adaptations to resistance training.
Kerksick C, Harvey T, Stout J, et al. International Society of Sports Nutrition position stand: Nutrient timing. J Int Soc Sports Nutr, 2008;5:17.
I know it is not research, but here is a link for someone wishing to start a weight training routine. It is geared towards men, but I am sure women could follow it as well by adjusting the rep schemes. The reason I am posting this is the author, Jim Stoppani PhD, is an excellent scientific editor for many muscle magazines and very knowledgeable in the field of exercise science.