Short version: buy whey if you want one protein powder that's cheap, mixes into anything, and matches what most of the training research actually used. Buy casein if you specifically want something slow and thick — last thing at night, or across a long gap between meals. Running both is fine; they came out of the same milk. And if you already eat dairy every day, there's a fair chance you need neither.
We earn a commission on both products linked below, and it doesn't move the verdict, because the verdict comes from the trials. Including the one that invented the whole "fast protein versus slow protein" idea — which ended the opposite way to how it gets quoted.
Key takeaways
- In the 1997 trial that created the fast-vs-slow framing, net leucine balance over seven hours — the trial's own index of whole-body protein balance — was more positive with casein than whey (P < 0.05), at identical leucine intake. Everyone quotes the first half of that study; nobody quotes the second.
- Whey does win on acute muscle protein synthesis, and it isn't close — roughly 93% higher than casein at rest and 122% higher after lifting, at a matched dose. That's a measurement over hours, not an outcome over months.
- Three long-term head-to-head training trials. One found whey far ahead, one found casein far ahead, and the most recent found no difference in anything. All were small. That is the honest state of the evidence.
- The famous bedtime-casein trial used a non-caloric placebo as its control, so the casein group ate about 1.9 g/kg/day of protein against the placebo group's 1.3. The ISSN position stand that recommends pre-sleep casein discloses this itself.
- Milk protein is roughly 80% casein. Cottage cheese, quark and Greek yoghurt are casein foods, and they cost less than either tub.
Whey vs. casein at a glance
| Whey | Casein | |
|---|---|---|
| Share of milk protein | ~20% | ~80%4 |
| What it is | The liquid fraction left when milk curdles | The curd itself |
| Dominant proteins | β-lactoglobulin and α-lactalbumin (75% of bovine whey protein)4 | Casein micelles |
| Behaviour in the gut | Water soluble, mixes easily, rapidly digested4 | Water insoluble; coagulates in the gut, and its opioid peptides slow gastric motility4 |
| Plasma amino-acid curve | "Dramatic but short" rise1 | Prolonged plateau of moderate hyperaminoacidemia1 |
| Whole-body protein synthesis, single meal | +68%1 | +31%1 |
| Whole-body protein breakdown, single meal | Not inhibited1 | Inhibited by 34%1 |
| Net leucine balance over 7 h | Lower | More positive (P < 0.05)1 |
| Acute muscle protein synthesis, matched dose | ~93% higher at rest, ~122% higher post-exercise2 | Reference |
| Leucine content | ~11% of protein4 | ~9.3% of protein4 |
| Essential amino acids, measured | 43% of protein7 | 34% of protein7 |
| Texture and mixability | Thin, dissolves readily | Thick, gels, needs more liquid |
| Typical cost per gram of protein | Lower | Higher |
| Best for | One all-purpose tub; around training | Long gaps between meals; before bed |
| The food version | Whey is the liquid drained off strained yoghurt | Cottage cheese, quark, Greek yoghurt |
The rest of this page is where those rows come from — and where they stop meaning what the marketing says they mean.
What each one actually is
Whey: the liquid left over
Whey is the watery fraction that separates when milk curdles — about a fifth of milk's protein. Add acid to milk and the casein coagulates and collects at the bottom while the whey stays on top; both fractions are then filtered to strip out lactose and fat.4 It's dominated by β-lactoglobulin and α-lactalbumin, which together make up around 75% of bovine whey protein.4 Because whey stays soluble, it clears the stomach quickly, which is the entire basis of its reputation. If you want the graded version of what whey does and doesn't do, that's our full evidence review of whey protein.
Casein: the curd
Casein is the other 80% — the part that becomes cheese.4 It is water insoluble, coagulates in the gut, and carries opioid peptides that slow gastric motility, so it empties gradually rather than in one wave.4 That's the mechanism behind every "slow-release" claim on a casein tub, and unlike most supplement mechanisms it's real and uncontroversial.
You'll see two casein types on labels. Micellar casein is the intact protein, which is the slow one; calcium caseinate is acid-treated and dissolves more easily, which partly undoes the point. If you're buying casein for slowness, buy micellar.
The study that started "fast vs slow" — and how it actually ended
Here is the paper. In 1997, Boirie and colleagues fed healthy adults a single meal of either casein or whey, both labelled with ¹³C-leucine, and tracked whole-body protein turnover for seven hours.1 Every article you have ever read about protein speed traces back to this study.
The first half is the half everyone quotes. Whey produced "a dramatic but short" rise in plasma amino acids and stimulated postprandial protein synthesis by 68%; casein produced a prolonged plateau of moderate hyperaminoacidemia — the authors attributed it to slow gastric emptying — and stimulated synthesis by only 31%.1 Fast protein, big spike, more synthesis. That is where the internet stops reading.
The second half is the part that matters. Casein inhibited whole-body protein breakdown by 34%, which whey did not do at all.1 Leucine oxidation over the seven hours was lower on casein (272 ± 91 µmol/kg) than on whey (373 ± 56 µmol/kg), and leucine intake was identical in both meals at 380 µmol/kg.1 Which leads to the sentence in the abstract that no page-one result for this query reproduces:
"Therefore, net leucine balance over the 7 h after the meal was more positive with CAS than with WP (P < 0.05, WP vs. CAS)."1
Two different mechanisms, then. Whey pushes synthesis up; casein holds breakdown down. Over the seven hours actually measured, the breakdown route came out slightly ahead — in the founding trial of the fast-protein story, on the trial's own primary measure.
It is one meal, in a small group of healthy adults, measuring whole-body leucine kinetics — not muscle. That distinction is the standard criticism, and it comes from the ISSN's own position stand: Boirie's group measured whole-body protein balance rather than myofibrillar muscle protein synthesis, and muscle contributes only an estimated 25–50% of whole-body protein synthesis, so whole-body turnover may poorly reflect what muscle is doing.4
The two meals were also not protein-matched. Subjects received about 30 g of whey against 43 g of casein, matched on leucine rather than grams.4 More casein protein went in, even though leucine intake was identical.1
So this trial does not show that casein builds more muscle. It shows that the popular one-line version of it — fast protein wins — is a simplification of a result that, on its own terms, went the other way.
Where whey genuinely wins: acute muscle protein synthesis
We're not cherry-picking, so here's the study that cuts the other way, and it's a strong one.
Tang and colleagues gave young men drinks matched at 10 g of essential amino acids — whey hydrolysate, micellar casein, or soy isolate — and measured mixed muscle protein synthesis at rest and after unilateral leg resistance exercise. At rest, synthesis rates were whey 0.091 ± 0.015, soy 0.078 ± 0.014 and casein 0.047 ± 0.008 %/h; whey was about 93% greater than casein at rest (P < 0.01) and about 122% greater after resistance exercise (P < 0.01).2 That is a large, replicated, muscle-specific advantage, and it's the honest answer to "which one spikes muscle protein synthesis harder."
Now the pivot the brand blogs never make. This is an acute measurement over hours, in six men per group, using whey hydrolysate rather than the concentrate in a standard tub.2 A bigger synthesis response for a few hours after one drink is a plausible reason to expect more muscle over a year. It is not evidence of more muscle over a year. For what that whole category is actually worth, see our muscle-growth hub.
So what happened when someone trained people for months?
This is the question the acute data can't answer, and the answer is more interesting than either side admits: the long-term head-to-head trials disagree with each other.
Cribb 2006 — whey wins, enormously. Thirteen male recreational bodybuilders supplemented with hydrolysed whey isolate or casein at 1.5 g/kg/day through a 10-week supervised resistance-training program. The whey group gained 5.0 ± 0.3 kg of lean mass against 0.8 ± 0.4 kg for casein (P < 0.01), lost fat where the casein group gained a little, and improved more on every strength measure.8
Demling 2000 — casein wins, enormously. Overweight police officers did 12 weeks of hypocaloric dieting plus resistance training with either a casein hydrolysate or a whey hydrolysate, again at 1.5 g/kg/day. The casein group lost 7.0 ± 2.1 kg of fat against 4.2 ± 0.9 kg, gained 4 ± 1.4 kg of lean mass against 2 ± 0.7 kg, and improved strength by 59 ± 9% against 29 ± 9% — a significant group difference.9
Wilborn 2013 — nobody wins. Sixteen NCAA Division III female basketball players were matched on body mass and randomised, double-blind, to 24 g of whey or 24 g of casein immediately before and after exercise across eight weeks of supervised, undulating periodised training, with DXA body composition and a full performance battery. Both groups improved on essentially everything — lean mass, body fat, leg press, bench press, vertical jump, agility. No significant group × time interaction was observed on any variable (p > 0.05). In the authors' words, "there does not appear to be a difference in the performance-enhancing effects between whey and casein proteins."12
All three are small, and the two that found a winner are also the two that report effect sizes frankly hard to believe for a swap between two milk proteins — five kilograms of lean mass in ten weeks in trained bodybuilders is not an ordinary result. Read together they cancel: two extreme results pointing opposite ways, and a third, more recent trial that found nothing. What survives is the boring conclusion: no reliable long-term evidence separates these two on muscle outcomes, and whoever is selling you one of them is citing exactly one of the first two studies and never the third.
Worth flagging who was studied, because it's the pattern across this whole category: Cribb enrolled men, Demling enrolled men, and the only one of the three that enrolled women is the one that found no difference.
Casein before bed: what the trial really showed
The pre-sleep case rests on Snijders and colleagues, 2015 — and it deserves to be reported in full, results and design both.
Forty-four young men completed 12 weeks of progressive resistance training. One group took 27.5 g of casein protein with 15 g of carbohydrate and 0.1 g of fat every night before sleep; the other took a non-caloric placebo.34 The results were large and real: strength rose +164 ± 11 kg versus +130 ± 9 kg (P < 0.001), quadriceps cross-sectional area +8.4 ± 1.1 cm² versus +4.8 ± 0.8 cm² (P < 0.05), and type II fibre size +2,319 ± 368 µm² versus +1,017 ± 353 µm² (P < 0.05).3 The trial's registration confirms the control arm as a non-caloric placebo drink.11
A non-caloric placebo means the casein group simply ate more protein. The ISSN position stand — the same document that recommends 30–40 g of pre-sleep casein — states it plainly: the study "was non-nitrogen balanced and the protein group received approximately 1.9 g/kg/day of protein compared to 1.3 g/kg/day in the placebo group."4
That gap straddles the number that matters. The largest meta-analysis on protein and resistance training, pooling 49 studies and 1,863 participants, put the break point for further gains in fat-free mass at roughly 1.62 g/kg/day (95% CI 1.03–2.20) — reported despite the underlying segmental regression missing significance at p = 0.079.6 The placebo group sat below that estimate; the casein group sat above it. You cannot tell from this trial whether bedtime did anything at all.
Two other lines of evidence point the same way. Schoenfeld's meta-analysis of protein timing found no significant timing effect on strength or hypertrophy once covariates were controlled, with total protein intake the strongest predictor of effect size (P = 0.004) — results the authors said "refute the commonly held belief that the timing of protein intake in and around a training session is critical."5 And when Antonio and colleagues gave 26 trained men and women 54 g of casein for eight weeks either in the morning or within 90 minutes of sleep, with total protein intake equal between groups, there were no between-group differences in body composition or performance.10 Small study, self-reported diets — but it's the one that controls the variable Snijders couldn't.
The defensible line: eating protein before bed is a perfectly good way to add protein to your day, and casein suits the job because it's slow and filling. The ISSN's 30–40 g pre-sleep casein recommendation sits on this evidence base.4 Whether the bedtime part does anything independent of the extra protein is not established. Your daily total is the number that's actually doing the work — see how much protein you need per day.
Which one is more filling?
Casein has the better mechanism by a distance: it coagulates in the stomach and its opioid peptides slow gastric motility, so it leaves more slowly.4 Slower emptying is a genuine, well-described route to feeling fuller for longer, and it's why casein is the sensible pick if appetite is the problem you're solving.
We'll stop there rather than hand you a number: the head-to-head appetite evidence in humans is thinner than the marketing implies, and we found no figure we were willing to stand behind. Treat casein's satiety edge as a well-reasoned bet, not a measured result — and remember the much bigger lever, which is that total protein and total calories decide a diet long before the choice between these two tubs does.
Can you take both?
Yes, and the answer is boring: they're both milk protein and both count toward the same daily total, which is the number that matters.56 There is no interaction to manage and no need to keep them apart. A common setup is whey in the day and casein at night, which is fine — just don't imagine it's doing something arithmetic can't explain.
The real considerations are cost and cupboard space. Two tubs cost more than one, and for most people one tub of whey plus an actual dairy food at night gets to the same place.
Cost, mixability and taste
If you've wondered why casein is the less popular tub, it comes down to three things, and they're the same three things people mean when they ask what casein's downside is.
Cost. Casein is consistently the pricier of the two per gram of protein. Check the current price on whatever you're considering; the ratio moves with promotions, but the direction doesn't.
Texture. Whey is water soluble and mixes easily.4 Casein is water insoluble and gels4 — in a shaker that means a thicker, sometimes gritty drink that needs more liquid and more shaking. Some people like it (it makes a decent pudding); plenty of people quietly stop buying it.
Range. Whey has thirty years of flavour development and post-workout marketing behind it. Casein has neither.
And both are milk proteins, which means neither is an option with a milk allergy, and both can be uncomfortable if you're lactose sensitive. That last one is a processing question rather than a whey-versus-casein one — see whey isolate vs. concentrate.
Or just eat the casein
Here's the section that costs us money.
Milk protein is about 80% casein.4 The way you make casein is to acidify milk so the curd separates and the whey drains off4 — which is precisely what cottage cheese, quark, and strained Greek yoghurt are. They are casein foods. You do not need a tub to eat casein before bed; you need a supermarket.
So if you've been wondering whether Greek yoghurt is whey or casein: mostly casein. Which reframes the whole comparison. A protein powder is a convenience food — cheap protein you don't have to chew, in a container that doesn't spoil. It wins on portability, cost per gram, and hitting a daily target you're currently missing. It doesn't win on anything metabolic that a bowl of cottage cheese wouldn't also do.
Which should you buy?
| Use case | Verdict | Why |
|---|---|---|
| One protein, general use, best value | Whey | Cheaper per gram, mixes better, more flavours — and it's what most of the training literature used |
| Around training | Whey | Larger acute synthesis response (~122% greater than casein post-exercise at a matched dose)2 — though your daily total matters more5 |
| Last thing at night, or long gaps between meals | Casein | Coagulates and empties slowly4; ISSN suggests 30–40 g pre-sleep4 — read it as "extra protein, conveniently timed" |
| Appetite control on a diet | Casein, tentatively | The slow-emptying mechanism is well described4; the head-to-head appetite evidence is thinner than the marketing |
| Lactose sensitivity | Whey isolate — neither of these | A processing question, not a whey-vs-casein one → whey isolate vs. concentrate |
| Milk allergy, or vegan | Neither | Both are milk proteins → pea protein vs. whey |
| You already eat dairy every day | Probably neither | Cottage cheese, quark and Greek yoghurt are casein foods4; milk is both |
| Budget | Whey | Consistently cheaper per gram of protein than casein |
If you want a specific tub for each job, these are the two we'd point a friend to. They're deliberately the same brand and the same product line, which is the only way a comparison like this makes sense: it isolates the protein as the variable instead of confounding it with brand quality. We may earn a commission if you buy through these links, and it doesn't change which protein we recommend for which job.
If you want one tub for everything
We may earn a commission if you buy through this link, at no extra cost to you. We have not reviewed or tested this product and publish no score for it — it's here because it's a mainstream, widely available whey, matched to the casein below so the protein is the only variable.
If you want the slow one for nights and long gaps
We may earn a commission if you buy through this link, at no extra cost to you. We have not reviewed or tested this product and publish no score for it — and this page says plainly that the bedtime evidence behind it can't separate timing from total protein.
Check the Supplement Facts panel on whatever you buy: protein per scoop varies between flavours and formulations get revised, and the number on the tub is the one that counts.
One aside, since the audiences overlap almost entirely: neither of these is really a performance supplement — a protein powder is a grocery decision. If what you're actually building is a supplement budget for muscle, the other item worth your attention is creatine.
Frequently asked questions
Neither is better in the abstract. Whey produces a bigger, faster rise in muscle protein synthesis; casein digests slowly and suppresses whole-body protein breakdown. In the original 1997 trial comparing them, casein actually produced the more positive net protein balance over seven hours, at identical leucine intake.
The bottom line
The gap between these two proteins is smaller than the gap between their price tags. Whey wins the acute muscle protein synthesis contest decisively2 and is cheaper and easier to drink, which makes it the right default if you're buying one. Casein empties slowly4 and is the better tool for a long gap or a late night — with the caveat, which the ISSN prints itself, that the trial behind the bedtime claim gave one group more protein than the other.4 The long-term head-to-head trials point in opposite directions, and the most recent found no difference at all.8912 Meanwhile the variable that reliably predicts results is your total daily protein.56
So: whey if you're buying one. Casein if you want the slow one and don't mind paying for it. Both if you like both. And if you eat cottage cheese, you have already been buying casein for years.
References
- Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrère B. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U S A. 1997;94(26):14930–5. (Whey: "dramatic but short" plasma amino-acid rise, postprandial protein synthesis +68%. Casein: prolonged plateau of moderate hyperaminoacidemia, synthesis +31%, whole-body protein breakdown inhibited 34%. Leucine oxidation over 7 h: casein 272 ± 91 vs whey 373 ± 56 µmol/kg; leucine intake identical at 380 µmol/kg. "Net leucine balance over the 7 h after the meal was more positive with CAS than with WP (P < 0.05).") pubmed.ncbi.nlm.nih.gov
- 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;107(3):987–92. (Three groups of six young men, matched at 10 g essential amino acids. Mixed muscle protein synthesis at rest: whey 0.091 ± 0.015, soy 0.078 ± 0.014, casein 0.047 ± 0.008 %/h; whey ~93% greater than casein at rest and ~122% greater after resistance exercise, both P < 0.01. PubMed record — the publisher's site blocks automated link checking.) pubmed.ncbi.nlm.nih.gov
- Snijders T, Res PT, Smeets JS, van Vliet S, van Kranenburg J, Maase K, Kies AK, Verdijk LB, van Loon LJ. Protein Ingestion before Sleep Increases Muscle Mass and Strength Gains during Prolonged Resistance-Type Exercise Training in Healthy Young Men. J Nutr. 2015;145(6):1178–84. (44 men aged 22 ± 1 y, 12-week progressive resistance training; 27.5 g protein + 15 g carbohydrate + 0.1 g fat before sleep vs a noncaloric placebo. Strength +164 ± 11 vs +130 ± 9 kg, P < 0.001; quadriceps CSA +8.4 ± 1.1 vs +4.8 ± 0.8 cm², P < 0.05; type II fibre size +2,319 ± 368 vs +1,017 ± 353 µm², P < 0.05. Registered as NCT02222415.) pubmed.ncbi.nlm.nih.gov
- Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. (Daily intake 1.4–2.0 g/kg/day; "pre-sleep casein protein intake (30–40 g) provides increases in overnight MPS and metabolic rate." Also: "milk proteins are 80% casein"; whey is high in β-lactoglobulin and α-lactalbumin, 75% of total bovine whey proteins; whey and casein leucine content 11% and 9.3% respectively; "casein is water insoluble, coagulates in the gut and is digested more slowly than whey protein… Casein also has intrinsic properties such as opioid peptides, which effectively slow gastric motility"; acid addition causes casein to coagulate while whey is left on top. On Boirie: subjects were given "a 30 g bolus of whey protein and a 43 g bolus of casein protein," and the study measured whole-body rather than myofibrillar protein balance, with muscle contributing an estimated 25–50% of whole-body protein synthesis. On Snijders: the trial "was non-nitrogen balanced and the protein group received approximately 1.9 g/kg/day of protein compared to 1.3 g/kg/day in the placebo group," and the supplement contained 27.5 g of casein protein.) pmc.ncbi.nlm.nih.gov
- Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013;10:53. (No significant timing effect on strength or hypertrophy in the full model controlling for all covariates; total protein intake was the strongest predictor of effect-size magnitude, estimate 0.41 ± 0.14, CI 0.14–0.69, P = 0.004. The authors state the results "refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations.") pmc.ncbi.nlm.nih.gov
- Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376–384. (49 studies, 1,863 participants. Break-point analysis, 42 study arms and 723 participants: break point 1.62 (1.03, 2.20) g/kg/day, presented "despite not being statistically significant (p=0.079)". PMC record — BMJ's own site blocks automated link checking.) pmc.ncbi.nlm.nih.gov
- Gorissen SHM, Crombag JJR, Senden JMG, Waterval WAH, Bierau J, Verdijk LB, van Loon LJC. Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids. 2018;50(12):1685–1695. (Measured essential amino acid content as a share of protein: whey 43%, milk 39%, casein 34%, egg 32%, human muscle protein 38%. Table 1, in g per 100 g raw material, gives leucine as whey 8.6, caseinate 7.8, milk 7.0 and casein 5.8.) pmc.ncbi.nlm.nih.gov
- Cribb PJ, Williams AD, Carey MF, Hayes A. The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine. Int J Sport Nutr Exerc Metab. 2006;16(5):494–509. (13 male recreational bodybuilders, 10-week supervised resistance training, hydrolysed whey isolate vs casein at 1.5 g/kg/day. Lean mass +5.0 ± 0.3 kg vs +0.8 ± 0.4 kg, P < 0.01; fat mass −1.5 ± 0.5 kg vs +0.2 ± 0.3 kg, P < 0.05; greater strength improvements on every measure.) pubmed.ncbi.nlm.nih.gov
- Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Ann Nutr Metab. 2000;44(1):21–9. (12 weeks; diet alone n=10, diet + resistance training + casein hydrolysate n=14, diet + resistance training + whey hydrolysate n=14, both at 1.5 g/kg/day. Fat loss 2.5 ± 0.6 / 7.0 ± 2.1 / 4.2 ± 0.9 kg; lean mass change 0 / +4 ± 1.4 / +2 ± 0.7 kg; strength +59 ± 9% for casein vs +29 ± 9% for whey, a significant group difference.) pubmed.ncbi.nlm.nih.gov
- Antonio J, Ellerbroek A, Peacock C, Silver T. Casein Protein Supplementation in Trained Men and Women: Morning versus Evening. Int J Exerc Sci. 2017;10(3):479–486. (26 trained men and women, 8 weeks, 54 g casein before noon (n=14) or within 90 minutes of sleep (n=12). Both groups raised protein intake with no between-group difference, and there were "no within- or between-group differences for any other measure.") pmc.ncbi.nlm.nih.gov
- ClinicalTrials.gov, NCT02222415 — "The Impact of Timed Protein Supplementation to Maximize the Skeletal Muscle Adaptive Response to Resistance Type Exercise Training in Healthy Young Men" (the Snijders 2015 registration). Records the comparator arm as "Exercise + non-caloric placebo drink." Accessed 25 July 2026. clinicaltrials.gov
- Wilborn CD, Taylor LW, Outlaw J, Williams L, Campbell B, Foster CA, Smith-Ryan A, Urbina S, Hayward S. The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes. J Sports Sci Med. 2013;12(1):74–79. (16 NCAA Division III female basketball players matched on body mass and randomised double-blind to 24 g whey (n=8) or 24 g casein (n=8) immediately pre- and post-exercise for 8 weeks of supervised 4-day/week undulating periodised training; DXA body composition plus 1RM, muscle endurance, vertical jump, 5-10-5 agility and broad jump. "No significant group x time interaction effects were observed among groups in changes in any variable (p > 0.05)." Significant time effects in both groups for body fat, lean mass, fat mass, leg press and bench press 1RM, vertical jump, agility and broad jump. "There does not appear to be a difference in the performance-enhancing effects between whey and casein proteins.") pubmed.ncbi.nlm.nih.gov