Category: Diet

Protein intake and sports performance

Protein intake and sports performance

No changes in body composition were reported, dports importantly, no clinical side effects Protein intake and sports performance observed throughout the study. Benefits of low-carb diets MJ, Kinsey Back pain relief, Eddy WR, Madzima TA, Arciero PJ, Proten A, et al. Intakf healthy people, a recent study suggested a performabce intake of 2 to 2. Dietary protein distribution positively influences h muscle protein synthesis in healthy adults [published online January 29, ]. When females were the only sex investigated, the outcomes consistently indicated that supplemental protein does not appear to enhance maximal strength at magnitudes that reach statistical significance. Our consensus opinion is that leucine, and possibly the other branched-chain amino acids, occupy a position of prominence in stimulating muscle protein synthesis; that protein intakes in the range of 1. Protein intake for athletes.

Protein intake and sports performance -

Athletes may require protein for more than just alleviation of the risk for deficiency, inherent in the dietary guidelines, but also to aid in an elevated level of functioning and possibly adaptation to the exercise stimulus. It does appear, however, that there is a good rationale for recommending to athletes protein intakes that are higher than the RDA.

Our consensus opinion is that leucine, and possibly the other branched-chain amino acids, occupy a position of prominence in stimulating muscle protein synthesis; that protein intakes in the range of 1.

Very few studies have actually utilized highly trained individuals or athletes, so translating the current findings to this population should be done with caution.

Finally, it is worth noting that several studies have shown the addition of carbohydrate and creatine monohydrate to a protein supplement, typically whey protein, results in greater strength and hypertrophy improvements from resistance training programs Perhaps a driving factor in performance i.

Recovery from exercise has been measured through many different methods in previous research. Delayed onset muscle soreness DOMS , which is defined as an aching pain in a given muscle following a novel exercise bout, has been measured subjectively Though the cause of DOMS is multifaceted and tied to a cascade of events linked to muscle damage, it is not necessarily an indicator of the magnitude of muscle damage and, therefore, cannot be used by itself to determine muscular recovery and adaptations from exercise Specific biomarkers and MPS rates appear to be the most efficient and widely used methods of objectively determining muscle breakdown, recovery, and adaptation from exercise.

Acute elevations of cortisol and creatine kinase CK are two biological indicators of muscle damage and the subsequent recovery processes that can be measured through blood sample analysis 30 , Post-exercise muscle biopsies can be used to determine rates of MPS, which directly measure the magnitude of the recovery process immediately following exercise West et al.

The protein group, however, appeared to improve whole body net protein balance over 24 h post-exercise. As noted previously, the subjects were already consuming 1. Interestingly, there was no difference between total body net protein balance between the groups.

It should be noted that whole body protein synthesis is not necessarily a reflection of skeletal muscle protein synthesis Kim et al. However, no differences were found in muscle protein synthesis between the 40 and 70 g dose. Thus, one must not conflate measures of whole body protein metabolism with those of skeletal muscle.

Nevertheless, the recovery of muscle function has been demonstrated in other studies 15 , 16 of milk protein supplementation after eccentric exercise, perhaps due to myofibrillar protein remodeling. The results of these studies further support the idea that protein consumed post-exercise is crucial for maximizing rates of protein synthesis in skeletal muscle.

The effect on total body protein balance, however, is still a bit unclear. Carbohydrates have been shown to have a protein sparing effect, therefore the combination of protein and carbohydrate to decrease rates of muscle protein breakdown MPB and increase rates of MPS may be the best strategy for shifting total body protein balance to the net anabolic side 34 , even if carbohydrate itself does not necessarily enhance MPS 35 , This may partially explain the benefits of the milk supplement used by Cockburn et al.

Perhaps there is a synergistic effect. In addition to the investigations discussed earlier regarding post-exercise protein quality and training adaptations, Burd et al. The researchers collected muscle biopsies and measured rates of MPS following resistance training. In the 0—2 h post-exercise window, the group that consumed 30 g of protein in the form of skim milk expressed higher rates of MPS than the group that consumed 30 g of protein from beef However, rates of MPS in the 2—5 h post-exercise window did not differ.

This may be explained by the rate of digestion and absorption of these protein sources. Protein from dairy, specifically the whey portion, appears to be absorbed faster, and elicit a faster MPS response than beef. The difference between whole egg and protein-equated egg white consumption post-exercise was also studied recently The researchers measured rates of MPS through muscle biopsies and found that the group that consumed the whole egg exhibited higher rates of MPS.

One limitation to this study was the lack of control for total calories and macronutrients. The whole egg treatment consisted of 18 g of protein, 17 g of fat, and kcal, while the egg white treatment consistent of 18 g of protein, 0 g of fat, and only 73 kcal While the discrepancy in calories between treatment groups may have impacted total daily calories, thus impacting MPS, one cannot ignore the possibility of the role that differences in macronutrients may play.

Lastly, a investigation looked at the differences between protein-equated native whey protein, whey protein concentrate, and milk Native whey protein is produced through the filtration of raw milk, while whey protein concentrate is a byproduct of cheese production.

Native whey protein consists of undenatured proteins and has a higher leucine content Each treatment consisted of ~20 g of protein, ~6 g of fat, and ~40 g of carbohydrates but contained 2.

The supplements were ingested immediately after and again 2 h post-exercise following a moderate intensity lower body resistance training session. Results showed higher blood amino acids concentrations in native whey and whey protein concentrate than in milk.

MPS was elevated in the whey protein condition from 1 to 3 h post, while it was elevated 1—5 h post in the native whey condition. There was no difference in MPS 1—5-h post-workout between native whey and whey protein concentrate, though MPS was higher from 1 to 5 h post-workout in the native whey condition compared to milk Collectively, these data support that whey protein, regardless of its levels of processing i.

whey protein concentrate , increase MPS by similar magnitudes that are greater than those of milk alone. How this translates to long-term differences remains to be determined. While the majority of the literature regarding the effects of protein intake on performance has focused on anaerobic activities, more recent work has examined its role on endurance activities, but this has mostly been absent from the most recent reviews.

Similar to resistance training, the impact appears to be at least somewhat dependent on the presence or absence of other nutrients, particularly carbohydrate. A systematic review and meta-analysis compared 11 studies investigating the effects of consumption of protein and carbohydrate vs.

consumption of carbohydrate alone during a bout of cycling on performance during a subsequent bout of cycling To investigate if the increased caloric intake due to inclusion of protein was responsible for this improved performance, a further analysis of isocarbohydrate and isocaloric conditions was performed.

Examination of isocarbohydrate conditions yielded a When considering only those studies measuring performance by time trial 3 , improvements were not statistically significant.

However, studies utilizing time to exhaustion protocols 8 did result in statistically significant improvements. It is worth noting that in all studies showing statistically significant improvement, whey protein was the source of protein utilized, though differences between concentrate vs.

isolate were not quantified. Again, it is prudent to highlight that performance improvements not reaching statistical significance may have clinical or practical relevance, specifically for athletes.

When discussing the impact of protein on performance, it is imperative to include the impact that protein may have on glycogen replenishment and subsequent exercise performance.

Standard discussions of glycogen replenishment focus solely on carbohydrate consumption. Recommendations for adequate post-exercise carbohydrate consumption are to consume 0. Carbohydrate consumption of 1. In cases of suboptimal post-exercise carbohydrate consumption, the addition of protein can improve glycogen replenishment and decrease symptoms of muscle damage Practical applications of standard post-exercise carbohydrate consumption recommendations may be limited in real world situations.

Beyond just glycogen replenishment aspects, it has also been shown that the presence of protein in rehydration beverages can enhance intestinal fluid uptake, aiding in rehydration 44 and that BCAA consumption during endurance exercise may improve time trial performance and peak power output while improving markers of immune health 45 and attenuate serotonin levels, subsequently resulting in a delay of central fatigue A systematic review by Pasiakos et al.

The authors included studies that measured markers of muscle damage followed by a test of physical performance or muscle function. Populations of the review included healthy individuals with daily dietary protein intake at or above the current RDA of 0. While some of the endurance exercise studies included showed decreases in markers of muscle damage, such as CK, or decreases in muscle soreness in groups consuming protein after initial exercise bout 47 — 49 , many did not 50 — This may have resulted from the inclusion of studies utilizing both trained and untrained subjects, as well as individuals consuming suboptimal daily protein intakes.

This evidence suggests that plasma CK levels, perceived level of muscle soreness, and muscle function may only be modestly related or perhaps utilizing a single method of measure paints an inadequate picture of recovery due to individual variability 5.

Without additional studies to clarify these relationships, developing guidelines based on these markers as representing recovery may be ill-advised.

Individuals must be cautious when attempting to measure recovery from exercise based on these metrics alone. On game days days 1 and 4 , the supplement was consumed immediately post-, 3 h post-, and 6 h post-match in three different doses of 25, 30, and 25 g, respectively, resulting in a total of 80 g.

On training days days 2, 3, 5, and 6 , 20 g of the supplement was consumed with breakfast. Additionally, knee extensor concentric strength recovered quicker after the first game following protein supplementation.

Endogenous antioxidant concentrations were greater following game two only in the protein-supplemented condition.

Since , additional work investigating the impact of protein consumption on biochemical markers of metabolic status, physiological fatigue, and recovery in endurance-trained athletes has been performed For 5 weeks, elite or experienced marathon runners received either Blood samples were collected to assess biochemical markers of metabolism, muscle damage, and fatigue and took place prior to beginning the intervention, 1 day following the marathon, and 1 week following the marathon.

These markers included CK, lactate dehydrogenase LDH , AST, and ALT. Runners who supplemented with whey protein displayed decreased AST and ALT compared to maltodextrin-supplemented runners. CK and LDH, biochemical indicators of muscle damage, were significantly greater in the maltodextrin group post-marathon compared to the whey protein-supplemented group.

Elevations in CK and LDH were still significant 1-week post-marathon in the maltodextrin group compared to the whey protein group The whey protein group also showed significantly decreased triglycerides TG and total cholesterol TC compared to the maltodextrin group post-marathon.

The maltodextrin group actually showed increased TC levels. Only the whey protein group showed significant decreases in LDL post-marathon and at 1 week post-marathon The authors suggested that the decrease in TC seen in whey-supplemented runners may indicate that cholesterol was more efficiently converted to steroid hormones, resulting in improved physiological recovery and adaptations from the strenuous exercise bout.

One week post-marathon, most biomarkers of damage and stress were still significantly lower in the whey protein group compared to the maltodextrin group Together, these results indicate that whey protein supplementation during marathon preparation and recovery, and that the supplement aids in attenuating metabolic and muscular damage.

Daily dietary assessments were not included in this study 54 , thus limiting possible practical applications or recommendations. Further studies are necessary to elucidate the potential contribution of peri-workout whey protein ingestion on makers of muscle damage, recovery, and subsequent performance measures in endurance athletes.

In real-world sport performance situations, recovery and performance must be evaluated in the context of an accumulated effect. The ability to train consistently while remaining healthy is critical for continued progression and optimal performance.

Endurance athletes in particular are at increased risk for upper respiratory tract infections Kephart et al. Additionally, Rowlands et al.

Post-exercise consumption of protein at levels thought to maximally stimulate MPS would potentially not have this same impact.

Post-exercise protein consumption affects other systems and pathways and should not be considered only in terms of stimulating MPS. As further evidence of this notion, Levenhagen et al. Although this supplementation protocol stimulated MPS, subjects were found to be in negative whole-body protein balance.

Because prolonged bouts of endurance exercise i. Because of this, protein requirements and recommendations for endurance athletes must consider more than MPS, especially since short-term increases in MPS do not fully explain the dynamics of long-term whole-body net protein balance and various training adaptations.

Overall, total daily energy and protein intake over the long term play the most crucial dietary roles in facilitating adaptations to exercise. However, once these factors are accounted for, it appears that peri-exercise protein intake plays a potentially useful role in optimizing physical performance and positively influencing the subsequent recovery processes.

Difficulties also arise in attempting to define and quantify the concept of recovery. Additionally, both performance and recovery must be viewed in context depending on whether the emphasis is an immediate, short-term effect i. It should also be noted that protein timing, whether it is pre-, during, or post-workout, is often framed within the context of bodybuilding i.

It is evident that to use such a narrow frame of reference ignores the potential utility of protein timing within the context of endurance events i.

For instance, if one competes in a weight-class sport e. In these situations, protein timing in particular may serve a useful role in recovery. Translating research into practical application requires differentiation between novice or trained individuals, healthy normal weight or healthy overweight individuals, special populations, or those with certain metabolic or disease states.

Here, we specifically focus on healthy, exercising individuals and limit our conclusions to these individuals. It is important moving forward that the study populations used are appropriate for the goals of the study and desired applications.

For example, it is of little use to have a sample of recreationally-trained individuals if the goal is to understand performance in high-level athletes. Though protein-containing meals result in increase of MPS on their own, as does resistance training, the timing of ingestion of protein around exercise further enhances this increase of MPS 63 , It is worth noting that an upper limit for this acute dosing has not really been established, though there is evidence that 40 g of protein stimulates MPS to a greater degree than 20 g following whole-body resistance training A dose higher than this, however, has not been included using the same timing paradigm.

With regard to endurance exercise, protein consumption during exercise may not confer an immediate ergogenic benefit, especially when carbohydrate consumption is adequate.

It may, however, aid in delaying central fatigue, reducing MPB, and contributing to a more positive, whole-body nitrogen balance. Additionally, protein consumption in and around intense or prolonged endurance activity may aid in reduction of upper respiratory tract infection incidence and improved immune system function.

It may also aid in upregulating gene expression of proteins necessary for improving bioenergetic pathways. The impact of this on subsequent training sessions should not be dismissed and is an important part of improving performance. The effect of protein consumption on resistance training is highly dependent on many variables not related to protein.

The combination of peri-training protein consumption with inadequate or ineffective resistance training protocols will not maximize improvements in strength or hypertrophy. Resistance training protocol interventions must be of adequate intensity, volume, and frequency with an emphasis on progressive overload to produce results.

Additionally, adequate training interventions coupled with calorie-restricted nutrition protocols may require increased protein intake of 2. Consideration must also be made for the age of resistance-trained individuals, as older adults require protein intake over and above that of their younger counterparts to receive the same benefits noted above In order to fully understand the role of protein or any substrate for that matter on performance, the practical application beyond the contrived training or recovery interventions presented must be addressed.

Daily training schedules of athletes require an ongoing ability to recover and perform. As an example, most of the studies included in this area utilized a training protocol that took ~3—4 h per week, typically in moderately-trained individuals.

For comparative purposes, a competitive athlete may spend 3—10 times this amount of time training per week if not more.

Protein dosing strategies need to take this into account. This becomes even more apparent when considering that the uniform distribution of protein throughout the day results in greater MPS than an uneven distribution even when total daily protein intake is equal Arciero et al.

These results suggest that the pattern of daily protein ingestion may also impact results from resistance training protocols and provides further evidence that we must look beyond the few hours following training to determine the impact that protein may have on performance and recovery.

Madzima et al. While no statistically significant changes were observed between groups, protein groups trended toward greater increases when compared to the carbohydrate group while morning fat oxidation was greatest in the casein supplemented group.

Taken together, these data demonstrate the need for a more comprehensive view and methods of measuring recovery. Increased sensitization of muscle to protein and nutrients for 24—72 h following training coupled with multiple weekly training sessions results in an on-going state of recovery.

By Alex St. John Last updated: June 25th, 15 min read. Many of those reading this will be aware of the general recommendation of 1 gram g of protein per pound lb of body mass However, it can be challenging to determine the specific protein requirements for athletes, as many factors can change the advised ranges.

Whether it is training status, individual sport, or dietary intake, many factors can influence recommendations for protein intake for athletes. Most data discussed in this article will deal with studies that used nitrogen balance to assess adequate protein requirements. From a physiological standpoint, to be in nitrogen protein balance means that protein nitrogen intake is equal to protein nitrogen loss While nitrogen balance is an accepted measure for assessing protein requirements, it has some drawbacks, which might result in recommendations that are too low Along with nitrogen balance and protein quantity recommendations, it is also vital to keep a note of the quality of protein athletes are ingesting.

Protein Type and Quality As many protein types exist, there is a range of protein quality and completeness that needs to be addressed when it comes to protein requirements Milk proteins whey and casein are typically rated as two of the highest qualities of proteins available while varying plant sources usually score the lowest Protein sources from eggs, beef, poultry, fish, and dairy are regularly viewed as excellent sources of protein A protein source with all of the essential amino acids in the correct amounts and proportions to increase muscle protein synthesis is known as a complete protein Dietary protein sources of animal origin are broadly classified as complete protein sources, while sources of plant origin are commonly missing one or more of the essential amino acids and must be combined with complementary incomplete protein sources The current recommended dietary allowance RDA of protein is 0.

However, a more recent analysis of the same data notes a value of 1. Also, further analysis of daily requirements for sedentary adults using a more accurate amino acid analysis technique Indicator Amino Acid Oxidation found a value of 1.

So overall, there exists a range in the literature when it comes to sedentary adults 0. This should be the absolute bare minimum that athletes ingest daily, but as athletes require more than the typical sedentary adult, read on to the next sections to determine individual needs based upon various situations.

Endurance athletes are no different; protein requirements vary depending upon training status, exercise intensity, workout duration, and dietary intake The best way to approach these variations is to classify athletes as recreational athletes those predominantly performing low- to moderate-intensity endurance exercise , modestly trained athletes, and elite endurance athletes Multiple studies have found that a recreational level of endurance training does not alter the amount of protein needed for that athlete 31, One such study by el-Khoury et al.

For modestly trained athletes, multiple studies have reported protein intakes of 0. These protein intakes resulted in net negative protein balances following exercise.

Recommendations of In terms of elite endurance athletes, a small collection of studies has examined their protein requirements. One found that 1. Another advised that 1. A further study by Brouns et al.

If an endurance athlete is interested in improving their endurance exercise performance, diets high in protein appear to offer no benefit. Still, they may help reduce psychological stress and declines in performance commonly seen during blocks on high-intensity training And ingestion of protein following resistance exercise is required for a positive protein balance Regular resistance exercise is also a source of stress and trauma that requires greater protein availability to recover A meta-analysis involving participants across 22 published studies has also demonstrated a positive impact of protein supplementation on improvements in fat-free mass and leg strength when compared to a placebo in both young and old populations 8.

An example of this is the near-universal finding of untrained or unaccustomed individuals needing increased amounts of dietary protein. Tarnopolsky et al. They concluded that the lowest intake compromised protein synthesis when compared to the moderate and high intakes and that while the moderate protein intake amounted to a neutral protein balance, they recommended one standard deviation above at 1.

Other studies have also suggested that protein intakes ranging from 1. The International Society of Sports Nutrition ISSN has also published position statements on the protein requirements of athletes, and they note 1.

And a consensus statement from ACSM et al. A fascinating and recent study was a systematic review, meta-analysis, and meta-regression by Morton et al. Data from the review, including 49 previous studies and participants, showed that protein supplementation significantly improved fat-free mass gains, maximal strength, muscle fibre diameter, and cross-sectional area of femur thigh mass The authors also noted that a protein intake higher than 1.

Two other studies by Antonio et al. Their first intervention had 30 resistance-trained individuals continue following their typical exercise training program alongside either a control or high-protein diet 4.

While the 30 participants were at a caloric surplus for 8 weeks, no changes in body mass, fat mass, fat-free mass, or per cent body fat were found when compared to the control group.

The participants followed either their normal diet of 2. Ultimately, the researchers found similar changes in strength, and the control group saw a significant increase in body mass. In contrast, the high-protein group saw a greater decrease in fat mass and per cent body fat 3. They theorised that those changes in fat-free mass they saw in both of the groups were the result of a different training stimulus.

Intermediate Strength Athletes 6 months — 2 years training : 1. And what is also important to consider is the speed at which an athlete loses body mass. To read the Research Review on making weight the wrong way, click here.

Proteim athletes require adequate Nutrigenomics and phytochemicals Back pain relief nutrient supply to support Back pain relief, development, and the demands associated with exercise and training. However, they are susceptible to ad inadequacies affecting performace health and physical performance. Food choices with nutrient adequacy and environmental protection is crucial for a sustainable diet. Therefore, we aimed to assess the adequacy of low-carbon diets to meet the protein requirements of adolescent athletes. Therefore, a cross-sectional observational study was conducted with 91 adolescent athletes from sports clubs in Rio de Janeiro who underwent anthropometric and food consumption assessments. Intske training for a local 10 intaoe run or the Olympics, Fasting and autophagy of all shapes, Refresh and purify body and levels sporta a common Infake to perform to the Back pain relief of their ability. Technical expertise and perfrmance are the cornerstones of improving athletic performance, but good nutrition performmance equally crucial for success. Over the last two decades, our understanding of the relationship between protein and exercise has grown vastly. We now know that it is not simply the quantity of protein consumed, but also the quality of that protein and when we consume it that dictates muscle health and function. The daily recommended allowance RDA for protein is 0. The vast majority of people consuming a typical western style diet easily achieve this level. However, scientists have begun emphasizing that these RDAs are minimum levels set to prevent deficiency rather than levels that will optimise health based on evidence from studies. Protein intake and sports performance

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