Quick Hit Summary

As most athletes know, protein is an integral part of post workout nutrition. Consuming a protein containing shake relatively soon (ie- within 1st hour post workout) appears to best maximize muscle growth and recovery. Additionally, you don’t have to take 50 grams of protein to take advantage of this effect. A recent study indicated that 20 grams of protein (~0.11 g/lb or ~0.05 g/kg) was just as effective as 40 grams of protein at stimulating muscle protein synthesis. Of the different types of protein on the market today, whey protein appears to be the best option. There are a few different types of whey protein- hydrolysate and isolate. Current research does not provide strong evidence that one form is superior to the other.

Goals of Post Workout Nutrition for Strength/Ball/Speed Sport Athletes

Previously, I discussed the importance of nutrition during the first few hours following an exercise session. For those who have not already done so, I strongly recommend reading Post Workout Nutrition as it will serve as the backdrop for the recommendations made here.

When working with strength/ball/speed sport athletes the primary goal of post workout nutrition is to assist the body as it goes from a state of catabolism (remember, the body is breaking down tissue during exercise) into anabolism (tissue growth). This is accomplished by ingesting protein and carbohydrates following an intense workout. Together these macronutrients function to increase the release of the anabolic hormone insulin, decrease the release of the catabolic hormone cortisol and supply the necessary building blocks (amino acids, glucose) required to build muscle tissue. In addition, glycogen stores, which are of more importance to those completing multiple workouts/competitions per day, will be restored. In this article, our main focus will be on post-workout protein (timing, amount and type). In the second half of this discussion, I’ll discuss the importance of including carbohydrates with any post-workout shake/meal.

Are you optimizing your post workout protein intake?²⁶

Timing of Protein

With protein synthesis naturally being elevated post exercise in muscle tissue, various investigators have studied how protein ingestion at specific time points affects muscle anabolism¹. In a small group of untrained subjects (3 men, 3 women), Rasmussen et al. observed that taking a post-workout shake (6 grams essential amino acids; 35 grams sucrose) at 1 or 3 hours post-exercise significantly increased protein synthesis compared to a placebo³. However, participants had the same anabolic response regardless of if they took the drink at 1 or 3 hours post exercise.

On the other hand, when taken on a long term basis, Hartman et al. provided evidence that taking protein within the first hour post exercise (vs. later in the day) did significantly increase protein synthesis in novice weight lifters⁴. For twelve weeks, participants took either a milk supplement (17.5 g protein, 25.7 g carbohydrate, 0.4 g fat) or an isocaloric maltodextrin drink immediately and again 1 hour post exercise. After this time period, participants were free to eat as pleased. At three different points during the study (weeks 0, 6 and 12) 3-day food records were kept. At each recording period, food records revealed that there were no significant differences in relative kcal or protein intake between subjects in either group (18 participants- milk; 19 participants- maltodextrin). Despite no significant differences in diet content throughout the trial, those consuming protein within the first hour had significantly greater gains in lean body mass and type II muscle (fast-twitch) hypertrophy compared to those consuming only carbohydrates.

Bird et al. also studied the effects that supplementation would have on muscle adaptations during a 12 week exercise program²⁹ in those consuming 625 ml of either protein (6 g), carbohydrates (Gatorade), combined protein+carb, or placebo (non-caloric flavored drink). Muscle fiber size, and changes in muscle breakdown (proteolysis) were measured both prior to and at the completion of the study. Data obtained at the end of the 12 week training program indicated that greatest increases in muscle size occurred in those consuming the EAA+CHO drink. Based off differences in muscle proteolysis (reduced 26% in CHO+PRO; increased 52% in placebo) these differences can partially be explained by reduced muscle catabolism with early supplementation. 3-day food records were completed at the start and end of the trial. Via email correspondence with lead author, Dr. Stephen Bird, I was informed that there were no significant differences in overall kcal intake between the groups²⁵. This strengthens the study’s conclusion that differences in hypertrophy were due to the post-workout supplementation protocol.

Table 1 Percent Change in Muscle Fiber Cross Sectional Area of type I (slow twitch), type IIa (fast twitch), and type IIb (fast twitch) over a 12 week training program. Irrespective of post workout supplement, all groups saw increases in muscle fiber size. Percents listed below represent the total increase in fiber size with respect to it’s pre-training size. *Post-training muscle fiber size significantly different from pre-training (P<0.05), Treatment group change in muscle fiber size is significantly different (P< 0.05) form Placebo (#), CHO ($), and EAA (+)²⁴.

Supplement	Type I	Type IIa	Type IIb
Placebo	7%*	9%*	7%*
CHO	18%*#	16%*#	14%*
EAA	13%*	17%*#	18%*#
CHO & EAA	23%*#+	27%*#$+	20%*#

For reference, type 1 muscle fibers are considered “slow twitch.” This fiber type is associated with endurance based exercise. In contrast, Type IIa & IIb are considered “fast twitch” muscle fibers. Pure strength and explosive movements (sprinting, jumping, max strength lifting) heavily rely upon these fiber types.

As you can see, the exact timing of when protein should be ingested to optimize post-workout recovery is being debated. The study by Hartman et al. is interesting though as those consuming drinks within the first hour did have significant increases in muscle size vs. those waiting > 1 hr⁴. Similar results have been observed in other studies as well²,²³,²⁴. Although this appears to conflict the results obtained by Rasmussen et al. (who showed no difference in protein synthesis when consuming drinks at 1 or 3 hours), one must remember that two factors contribute to muscle gain… Net Muscle Gain = Protein Gain (Anabolism) – Protein Loss (Catabolism). Most people forget that both of these processes can occur at the same time. Rather than one being completely shut off while the other is turned on, the process can be thought of as more of a teeter-totter. As indicated in the results obtained by Bird et al. results may have been as much from reducing muscle protein breakdown as it was stimulating protein synthesis²⁴.

Amount of Protein

To my knowledge only 1 study has directly studied how much protein is required to optimize muscle protein synthesis. This study, conducted by Moore et al., was reviewed in a previous WNF, Post Workout Protein Debate [5]. Rather than completely rehashing the study, I’ll just give a quick summary. On 5 separate occasions, resistance trained men consumed egg protein following a resistance training session. The amounts taken were 0, 5, 10, 20 and 40 grams. Final results indicated that protein synthesis peaked at the consumption of 20 grams. Protein beyond 20 grams was broken down and was used for purposes other than protein synthesis.

Figure 1 Increased rate of mixed muscle FSR (ie- muscle protein synthesis) with increasing doses of protein. In comparison to the fasted state, 5 grams of protein increases FSR by 37%, 10 grams by 56% and 20 g by 93%. There were no statistically significant increases in mixed muscle protein synthesis when going from 20 to 40 grams of protein⁵.

To help you understand the graph a little better, FSR is just one of the measurement techniques that researchers use to measure protein synthesis. In other words, anytime you see Mixed Muscle FSR, just substitute it with muscle protein synthesis.

As you can see in the above graph, despite doubling the amount of protein (going from 20 to 40 grams of egg protein) there was no significant increase in muscle protein synthesis. Also, for reference sake, the average man in the study weighed ~190 lbs (86 kg). Therefore, the average protein intake for each participant that maximized protein synthesis was around 0.11g protein/lb (0.05g/kg) of bodyweight. This equates out to 11 grams/100 lbs of bodyweight.

Type of Protein

There are hundreds of dietary protein sources out there. Thus, many investigators have asked the question, “What type of protein best stimulates protein synthesis following a workout.” The World Health Organization (WHO) measures the quality of proteins based off the Protein Digestibility–Corrected Amino Acid score (PDCAAS)⁶ as this account both the digestibility and essential amino acid content of a given protein source⁷. It has been shown that the true PDCAAS of cow’s milk is superior to that of egg, beef, soy and wheat⁶. Although the PDCAAS are accepted by the WHO, there are some problems with it. These include changes in protein quality with processing, and other ingredients in food/supplement products that prevent proper protein absorption⁸. Thus, several researchers have done direct comparisons with various protein sources following a resistance training session.

Milk Protein vs. Soy

One of the first studies on the acute affects of various protein sources on post-workout recovery was conducted by Wilkinson et al⁹. In their study, 8 resistance trained men (mean age- 21 years) performed two separate resistance training sessions. After each session they drank soy or milk beverages. Each drink contained the same amount of calories (kcal), nitrogen and equal amounts of each macronutrient (18.2 g protein, 1.5 g fat, and 23 g carbohydrate). The rate of protein synthesis was measured in the muscle for 3 hours following the completion of the exercise session. Final data indicated that milk protein resulted in a 34% greater rate of protein synthesis vs. the soy.

The study by Wilkenson et al. only looked protein synthesis following an acute training session⁹. Logically, the next question is, “What are the long term impacts of taking soy vs. milk protein in conjunction with a resistance training program?” Previously, I mentioned a study conducted by Hartman et al. (please see Protein Timing section). Besides looking at the long term (12 weeks) effects of taking protein following a workout, they also examined if taking milk or soy protein influenced lean muscle mass⁴. 19 men took a soy protein drink with similar nutrient content as the milk supplement (17.5 g protein, 25.7 g carbohydrate, 0.4 g fat). As mentioned above, there were no major differences in the 3 day food records that were taken at weeks 0, 6 and 12. Despite their overall diets being relatively similar, it was found that those who took the milk protein had significantly greater increases in type II muscle size (ie- increase size in fast twitch/explosive muscle fibers). Interestingly, there was no significant difference in mean bodyweight between both groups at the start and at the end of the 12 weeks. Despite gaining the same amount of bodyweight over the 12 week period, the milk drinking group gained more lean body mass (ie- muscle mass) than the soy group. Therefore, if both groups experienced the same gain in body weight, this means that the soy group must have gained more fat mass. Although it’d be premature for one to state that soy beverages promote weight gain in the form of fat, I feel its one area that deserves further investigation.

Casein vs. Whey Protein at Rest

The studies by Wilkinson et al.⁹ and Hartman et al.⁴, in conjunction with the PDCAAS,⁶ supply strong evidence that milk may be the best source of protein during the post-workout hours. However, milk consists of two different types of protein. Casein accounts for 80% of the protein found in milk, whereas whey protein accounts for the remaining 20%¹⁰. Many researchers have examined if the type of dairy protein impacts protein synthesis. At rest, research has demonstrated that whey promotes protein synthesis to a greater extent than casein protein¹¹¹². On the other hand, casein protein appears more effective at preventing protein breakdown. Different digestive processes help to explain why casein has different physiological effects on protein anabolism/catabolism versus whey protein. Research has shown that protein synthesis is stimulated once blood amino acids reach 200% of base line levels¹³. Due to its chemical structure, casein is absorbed into the circulatory system in a slow, but prolonged fashion¹⁴. Although it raises circulatory amino acid levels, casein does not cause a great enough spike to induce significant levels of protein synthesis as most of the amino acids fail to reach at least 200% of basal levels¹¹. In contrast, whey proteins quickly digested and absorbed into the circulatory system¹⁴. As a result, amino acids derived from whey protein sources cause elevations as high as 274% of baseline levels 100 minutes following ingestion¹¹. Therefore, protein synthesis is stimulated within skeletal tissue.

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SIDEBAR DISCUSSION:

What’s Wrong with Eating Whey Protein All Day?

As a side note, due to the speed at which whey enters the body, its metabolized relatively quick and serum (blood) levels of amino acids are back at baseline 4 hours post-ingestion¹¹¹². In contrast, 7 hours following the consumption of casein protein, serum amino acid levels are still elevated, making it ideal to prevent muscle catabolism. Although one may be tempted to consume whey protein 4-6 times over the course of the day to keep serum amino acid levels above 200% all day long, research indicates that this isn’t the best idea. In a study conducted Bohe et al. 6 participants were given a continuous supply of amino acids for 6 hours. Despite significantly elevating serum amino acids for this duration, muscle protein synthesis was only elevated for a total of 90 minutes (there was a 30 minute delay between amino acids entering the blood stream and enhanced protein synthesis)¹⁵. After 2 hours the rate of protein synthesis quickly decreased back to baseline studies. Thus, researchers now believe that it is the fluctuations of amino acid levels (especially the branched chain amino acids: Leucine, Isoleucine & Valine) that stimulate protein synthesis. In other words, instead of trying to constantly keep serum amino acid levels above 200% of baseline, one wants to go from baseline to >200%, back down again, back up, etc.
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Casein vs. Whey Protein Post-Exercise

There have been two studies to my knowledge that have directly compared effects of casein to whey protein following a resistance training session. The first study, completed by Tipton et al. involved male and female participants, all in their 20’s¹⁶. One hour after an intense leg workout, participants received either 20 grams of either whey or casein protein. For the next 6 hours, Tipton et al. measured the effects of each drink on protein balance. Results of their study indicated that both types of protein stimulated muscle anabolism; yet neither of the proteins seemed to stimulate the process more than the other.

In a more recent study conducted by Tang et al., the ingestion of whey did cause a significant increase in protein synthesis vs. both casein and soy protein¹⁷. In their study, 18 resistance trained men (mean age-22.8 years) consumed ~22 grams of whey, casein or soy protein. The essential amino acid content of each drink was also balanced out to ~10g per drink. After completing a leg workout, each individual took their respective drink and levels of protein synthesis were measured for the following 3 hours. Final results indicated that the rate of muscle protein synthesis was 122% greater with whey protein vs. casein. In addition, it was 39% more effective than soy protein. In agreement with previous studies, casein did not significantly stimulate protein synthesis. Tang et al. suggest differences in their study vs. Tipton et al.’s¹⁶ may have been due to different measurement techniques. Rather than just measuring differences in circulatory amino acid content, Tang et al. measured the direct incorporation of amino acids into muscle tissue.

Whey Protein Isolates vs. Whey Protein Hydrolysates

Within the last 10 years, manufactures have been breaking down the types of protein even further. Now many proteins are being sold in both the intact protein form (ex- whey protein isolate, casein, etc) as well as a more refined form referred to as protein hydrolysates. Proteins can be made up of 100+ amino acids all of which are chemical linked to each other. In the digestive process, these proteins are broken down into smaller pieces, called di- and tri-peptides, before they are absorbed into circulation¹⁸. Hydrolysates are proteins which have already been broken down into individual di- and tri-peptides. It’s been demonstrated that egg and casein hydrolysates are absorbed faster than their intact proteins¹⁹²⁰. As mentioned by Manninen AH, quicker absorption of protein has two beneficial effects on muscular protein synthesis¹⁸. The first and most obvious benefit is quickly creating an anabolic environment within one’s body. The second benefit is that fewer amino acids are taken up by the gut and used for energy. Thus, more enters into general circulation, exposing muscle tissue to a higher concentration of amino acids.

Although studies have shown faster absorption with hydrolyzed forms of egg and casein protein, I’ve yet to see any strong evidence indicating hydrolyzed whey is absorbed faster than whey protein isolate. In a recently completed study, Powers et al. had 16 males (mean age- 22.4 years) complete two separate trials in which they drank beverages consisting of 45 grams of whey protein isolates (WPI) or hydrosylates (WPH)²¹. For the ensuing 3 hours, Powers et al. measured the rate of appearance of branched chain amino acids (BCAA’s), the essential amino acid phenylalanine, and insulin response. [BCAA’s are a collection of 3 highly anabolic amino acids- Leucine, Isoleucine and Valine]. Results indicated that rate of appearance and plasma concentration levels for BCAA were not significantly different between WPI and WPH. On the other hand, phenylalanine concentrations were significantly higher 30-60 minutes after ingestion. Although insulin levels tended to be higher after 3 hours with WPH vs WPI, the overall difference was not significant. It’s possible that whey protein isolate is digested so fast on its own, that the hydrolyzed form isn’t absorbed significantly faster than the intact form.

One study has investigated the effects of WPI vs WPH on muscle performance following an exercise session. Buckley et al., examined the effects of 25 grams of WPI or WPH on 17 sedentary men (age range: 18-30 years) on muscle recovery following 100 eccentric leg extensions²². Peak isometric force capabilities, muscle soreness and markers of inflammation were recorded both before and after exercise (Measurements taken just prior to exercise as well as 1, 2, 6 and 24 h post exercise.) Final results indicated that those taking the WPH recovered muscle strength 6 hours after the eccentric exercise and it remained elevated for the remainder of the trial. In contrast, those taking WPI never recovered strength levels over the following 24 hours. On the other hand, muscle soreness remained significantly elevated for participants regardless of the supplement consumed throughout the entire trial. Although muscle strength recovered faster for WPH, I must emphasize that this study was carried out on sedentary individuals. How these results would generalize to habitual exercisers is yet to be determined.

More research is still needed on this area. To my knowledge, there has yet to be a study directly comparing muscle protein synthesis following the ingestion of whey isolate vs. hydrolysates. Although you may get a slightly better anabolic/recovery effect from the WPH vs WPI, one must ask themselves if the added cost is worth the benefit. For elite level athletes where the extra inch makes all the difference, I would say yes. However, for the average individual simply looking to get stronger, I’d say no. That said, this is a decision I’ll leave to you.

Areas for Future Research

Although there has been some exciting research on the different types of protein, I feel direct comparisons with different types of animal proteins still needs to be examined. The only studies that I’ve seen comparing animal proteins are casein vs. whey protein. However casein is such a slow protein with respect to digestion and absorption, I don’t believe that it’s a good representation of “other” animal proteins. Thus, it’d be cool to see it compared to another fast, high quality animal protein such as egg.

Bottom Line

If I had to guess, protein powder is probably the most popular supplement amongst strength athletes. However, both the type of protein (whey, casein, egg, soy, etc) as well as the recommended serving size varies greatly from study to study. Based off the research presented above, whey protein, should be consumed shortly after a workout to best maximize the anabolic response. If the goal is simply maximizing muscle protein synthesis, consuming it in mega doses (40-50+ grams) does not appear to be warranted at this time.

And with that, this half of the article draws to a close. Stay tuned for the conclusion of this article where we examine the importance of carbohydrates and I pull everything together to give you my final recommendations regarding post workout nutrition for the ball/speed/strength athlete.

References

¹ Tang JE, Perco JG, Moore DR, Wilkinson SB, Phillips SM. Resistance training alters the response of fed state mixed muscle protein synthesis in young men. Am J Physiol Regul Integr Comp Physiol. 2008 Jan;294(1):R172-8. Epub 2007 Nov 21.

² Esmarck B, Andersen JL, Olsen S, Richter EA, Mizuno M, Kjaer M. Timing of postexercise protein intake is important for muscle hypertrophy with resistance training in elderly humans. J Physiol. 2001 Aug 15;535(Pt 1):301-11.

³ Rasmussen BB, Tipton KD, Miller SL, Wolf SE, Wolfe RR. An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J Appl Physiol. 2000 Feb;88(2):386-92.

⁴ Hartman JW, Tang JE, Wilkinson SB, Tarnopolsky MA, Lawrence RL, Fullerton AV, Phillips SM. Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutr. 2007 Aug;86(2):373-81.

⁵ Moore DR, Robinson MJ, Fry JL, Tang JE, Glover EI, Wilkinson SB, Prior T, Tarnopolsky MA, Phillips SM. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr. 2009.

⁶ Reeds, P., Schaafsma, G., Tome, D., & Young, V. (2000). Criteria and significance of dietary protein sources in humans. summary of the workshop with recommendations. The Journal of Nutrition, 130(7), 1874S-6S.

⁷ Schaafsma, G. (2000). The protein digestibility-corrected amino acid score. The Journal of Nutrition, 130(7), 1865S-7S.

⁸ Schaafsma G. The Protein Digestibility-Corrected Amino Acid Score (PDCAAS)—a concept for describing protein quality in foods and food ingredients: a critical review. J AOAC Int. 2005 May-Jun;88(3):988-94.

⁹ Wilkinson SB, Tarnopolsky MA, Macdonald MJ, Macdonald JR, Armstrong D, Phillips SM. Consumption of fluid skim milk promotes greater muscle protein accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic soy-protein beverage. Am J Clin Nutr. 2007 Apr;85(4):1031-40.

¹⁰ Lacroix, M., Bos, C., Leonil, J., Airinei, G., Luengo, C., Dare, S., et al. (2006). Compared with casein or total milk protein, digestion of milk soluble proteins is too rapid to sustain the anabolic postprandial amino acid requirement. The American Journal of Clinical Nutrition, 84(5), 1070-1079.

¹¹ Boirie, Y., Dangin, M., Gachon, P., Vasson, M. P., Maubois, J. L., & Beaufrere, B. (1997). Slow and fast dietary proteins differently modulate postprandial protein accretion. Proceedings of the National Academy of Sciences of the United States of America, 94(26), 14930-14935.

¹² Dangin, M., Boirie, Y., Garcia-Rodenas, C., Gachon, P., Fauquant, J., Callier, P., et al. (2001). The digestion rate of protein is an independent regulating factor of postprandial protein retention. American Journal of Physiology, Endocrinology and Metabolism, 280(2), E340-8.

¹³ Giordano, M., Castellino, P., & DeFronzo, R. A. (1996). Differential responsiveness of protein synthesis and degradation to amino acid availability in humans. Diabetes, 45(4), 393-399.

¹⁴ Mahe, S., Roos, N., Benamouzig, R., Davin, L., Luengo, C., Gagnon, L., et al. (1996). Gastrojejunal kinetics and the digestion of [15N]beta-lactoglobulin and casein in humans: The influence of the nature and quantity of the protein. The American Journal of Clinical Nutrition, 63(4), 546-552.

¹⁵ Bohé J, Low JF, Wolfe RR, Rennie MJ. Latency and duration of stimulation of human muscle protein synthesis during continuous infusion of amino acids. J Physiol. 2001 Apr 15;532(Pt 2):575-9.

¹⁶ Tipton KD, Elliott TA, Cree MG, Wolf SE, Sanford AP, Wolfe RR. Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise. Med Sci Sports Exerc 36: 2073–2081, 2004.

¹⁷ Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, Phillips SM. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol. 2009 Sep;107(3):987-92. Epub 2009 Jul 9.

¹⁸ Yoshizawa F. Regulation of protein synthesis by branched-chain amino acids in vivo. Biochem Biophys Res Commun. 2004 Jan 9;313(2):417-22.

¹⁹ Grimble GK, Rees RG, Keohane PP, Cartwright T, Desreumaux M, Silk DB. Effect of peptide chain length on absorption of egg protein hydrolysates in the normal human jejunum. Gastroenterology. 1987;92:136–42.

²⁰ Koopman R, Crombach N, Gijsen AP, Walrand S, Fauquant J, Kies AK, Lemosquet S, Saris WH, Boirie Y, van Loon LJ. Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein. Am J Clin Nutr. 2009 Jul;90(1):106-15. Epub 2009 May 27.

²¹ Power O, Hallihan A, Jakeman P. Human insulinotropic response to oral ingestion of native and hydrolysed whey protein. Amino Acids. 2009 Jul;37(2):333-9. Epub 2008 Aug 5.

²² Buckley JD, Thomson RL, Coates AM, Howe PR, Denichilo MO, Rowney MK. Supplementation with a whey protein hydrolysate enhances recovery of muscle force-generating capacity following eccentric exercise. J Sci Med Sport. 2008.

²³ Andersen LL, Tufekovic G, Zebis MK, Crameri RM, Verlaan G, Kjaer M, Suetta C, Magnusson P, Aagaard P. The effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength. Metabolism. 2005 Feb;54(2):151-6.

²⁴ Bird SP, Tarpenning KM, Marino FE. Independent and combined effects of liquid carbohydrate/essential amino acid ingestion on hormonal and muscular adaptations following resistance training in untrained men. Eur J Appl Physiol. 2006 May;97(2):225-38. Epub 2006 Mar 24.

²⁵ Bird, Stephen. “Attenuation of post exercise muscle catabolism.” Message to Sean Casey. Dec 13, 2009. Email.

²⁶ Photo by kteague. Accessed June 14 from: flickr.com/photos/49503205198@N01/3335735763