Supplement Reviews

 

What is Cellucor C4 Ripped?

Cellucor C4 Ripped is the next level of pre-workout supplement that contains the hard-hitting energy blend you know and love along with a high-level fat burning mix. While it contains several key fat-burning ingredients, the thermogenic portion of C4 Ripped cannot compare to EHP Labs OxyShred Ultra Thermogenic, which was designed exclusively for fat burning. Energy boosting is where C4 Ripped shines.

Highlights:

• Energy blend includes almost 400 mg of Velvet Bean, N-Acetyl-L-Tyrosine, and Caffeine Anhydrous (1-2). EHP Labs OxyShred Ultra Thermogenic also contains a potent energy blend in the form of a mood enhancement category. While the EHP Labs OxyShred Ultra Thermogenic energy blend is strong, it isn't on the same level as C4 Ripped. For example, when it comes to caffeine, EHP Labs OxyShred Ultra Thermogenic provides 150 mg total where C4 Ripped has 400 mg. of Caffeine, Velvet Bean and, N-Acetyl-L-Tyrosine, making it an intense energy supplement.
• Thermogenic (fat burning) blend features scientifically proven ingredients including L-Carnitine, Green Tea Extract, and Capsicum (1, 3-4). Again, while potent, the thermogenic blend isn't nearly as powerful as the one you'll find with EHP Labs OxyShred Ultra Thermogenic. This is more than apparent when you look at the dosages of both. The fat burning formula in C4 Ripped offers you one gram of a few thermogenic ingredients while OxyShred delivers nearly 7 grams of a variety of fat burners.
• Long lasting energy without the crash.

Why You Should Use Cellucor C4 Ripped

C4 Ripped is the upgrade that long-term fans were demanding. It combines the potent pre-workout energy formula that has been an industry staple for years with a uniquely dosed thermogenic blend to support fat loss.

If you are in need of serious energy to get through your workout AND you want to encourage fat burning to support goals of weight loss, shredding, or maintenance, then C4 Ripped is the supplement to use.

Things to Watch Out for With Cellucor C4 Ripped

It's important to understand that C4 is a pre-workout FIRST and a fat burner SECOND. C4 Ripped is better at supporting your energy needs than EHP Labs OxyShred Ultra Thermogenic. It also provides you with a slight boost in the department of fat burning; however, EHP Labs OxyShred Ultra Thermogenic was specifically designed for fat burning, making it superior in that regard.

If your primary goal is fat loss and energy isn't a concern for you, then you need to get set up with a real, scientifically proven fat incinerator, which is where EHP Labs OxyShred Ultra Thermogenic comes into play.

What is EHP Labs OxyShred Ultra Thermogenic?

EHP Labs OxyShred Ultra Thermogenic is an expertly designed fat burning supplement that contains a high dose of the industry's best fat burners. If you're goal is fat loss, EHP Labs OxyShred Ultra Thermogenic is here to help you achieve it.

Highlights:

• Solely focused on igniting your metabolic rate with proven ingredients such as Acetyl-L-Carnitine, Raspberry Ketones, and Conjugated Linoleic Acid (3, 5). C4 Ripped contains comparable ingredients but the difference is the dosage. EHP Labs OxyShred Ultra Thermogenic crushes C4 Ripped in the thermogenic department offering nearly 7 grams of high powered, fat burning ingredients.
• Also utilizes nootropics to improve cognitive function and mood.
• Provides you with an energy blend that may prove useful as a pre-workout; however, it doesn't compare to the extensive energy-focused ingredients used in C4 Ripped.

Why You Should Use EHP Labs OxyShred Ultra Thermogenic

Is your primary fitness goal to burn away excess body fat?

Do you have over 10, 20, or 30 kilograms to lose?

EHP Labs OxyShred Ultra Thermogenic is going to be a powerful ally in the fight against fat.

EHP Labs OxyShred Ultra Thermogenic isn't just another fat burner that only contains caffeine. This supplement was uniquely designed to include scientifically proven thermogenic compounds that have been shown to trigger fat burning. Used as a part of a healthy diet and exercise program, EHP Labs OxyShred Ultra Thermogenic can help you achieve your weight loss goals.

Things to Watch Out for with EHP Labs OxyShred Ultra Thermogenic

Due to the high dosage of potent thermogenics, it is important to consult your doctor before using this product. This is especially necessary if you have a history of high blood pressure.

Also, it's important to note that EHP Labs OxyShred Ultra Thermogenic is not the same as a pre-workout. You'll get an energy boost from EHP Labs OxyShred Ultra Thermogenic but this supplement is exclusively used for fat burning, not energy-boosting.

Conclusion

Both supplements are incredible at what they do best.

Considered one of the top 3 most popular pre-workouts in the entire industry. That's saying something considering there are hundreds to choose.

EHP Labs OxyShred Ultra Thermogenic is an insane fat burner that has perfected the ingredient list and dosage needed to trigger a metabolic response.

The difference between these two supplements isn't quality; rather, the difference is function. If you want to support energy levels, go with C4 Ripped. If you need help with fat burning, OxyShred Ultra Thermogenic is the supplement for you. If you need both energy AND fat burning, you can safely use both of these supplements to support your goals.

References

1. Westerterp-Plantenga MS, Lejeune MP, Kovacs EM. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Obes Res. 2005 Jul;13(7):1195-204.

2. F. L. Dodd, D. O. Kennedy, L. M. Riby, and C. F. Haskell-Ramsay. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology. 2015; 232(14): 2563–2576. Published online 2015 Mar 13.

3. Brandsch C, Eder K. Effect of L-carnitine on weight loss and body composition of rats fed a hypocaloric diet. Ann Nutr Metab. 2002;46(5):205-10.

4. Lejeune MP, Kovacs EM, Westerterp-Plantenga MS. Effect of capsaicin on substrate oxidation and weight maintenance after modest body-weight loss in human subjects. Br J Nutr. 2003 Sep;90(3):651-59.

5. Morimoto C, Satoh Y, Hara M, Inoue S, Tsujita T, Okuda H. Anti-obese action of raspberry ketone. Life Sci. 2005 May 27;77(2):194-204. Epub 2005 Feb 25.

For anyone who has a hard time putting on weight, there's nothing like an elite quality mass gainer. Loaded with the protein for muscle building and excess calories for mass, these supplements can make a huge difference for hard gainers.

 

Let's take a look at two of the best mass gainers in the industry, Optimum Nutrition Pro Complex Gainer and Optimum Nutrition Gold Standard Gainer to see which one is worth the buy.

 

 

Optimum Nutrition Pro Gainer

Where can I buy it?

• Here's where you can buy Optimum Nutrition Pro Gainer

 

Pros of Optimum Nutrition Pro Gainer

Pro Gainer has been a fan favourite for years and it's not hard to see why. At 650 calories per serving, this is one supplement that is serious about helping you gain the mass you want.

 

Every serving of Pro Gainer delivers 60 grams of protein along with 85 grams of carbohydrates, making it ideal as a muscle building supplement post-workout. We were really impressed by the protein blend that Optimum Nutrition uses which includes Whey Protein Isolate, Whey Protein Concentrate, Calcium Caseinate, Egg Albumin, Hydrolyzed Whey Peptides, and Glutamine Peptides. With the varying rates of digestion for each type of protein, you can rest assured you'll have plenty of muscle building amino acids for hours.

 

When used as directed, Pro Gainer may support muscle recovery, promote muscle growth, and trigger protein synthesis. (1-6)

 

Cons of Optimum Nutrition Pro Gainer

Two concerns we have with Pro Gainer:

 

First is with the vitamin and mineral blend. If you are taking a multi-vitamin, then you may want to take half of the dose since Pro Gainer delivers up to 50% of what you'll need on a daily basis.

 

Second is with the maltodextrin as the front and centre ingredient. Maltodextrin is a simple carbohydrate source used in many mass gainers. Since it's a simple carbohydrate, it may spike insulin levels like a quick carb food would. With that said, it's best to use this product first thing in the morning or immediately following a workout.

 

 

Optimum Nutrition Gold Standard Gainer

Where can I buy it?

• Here's where you can buy Optimum Nutrition Gold Standard Gainer

 

Pros of Optimum Nutrition Gold Standard Gainer

The Gold Standard series of supplements from Optimum Nutrition has been one of the best in the industry. From the pre-workout to the protein, Gold Standard has set itself high above other supplement brands. The Gold Standard Gainer is no different. Packed with 760 calories from quality ingredients per serving, Gold Standard Gainer is ready to help you accomplish your size goals.

 

Gold Standard Gainer gives you 55 grams of protein and 110 grams of carbohydrates. The amazing thing about the carbohydrate blend is that it is primarily from oat, pea and potato. Yes, you'll find maltodextrin in there as well but the bulk is coming from a complex carb source.

 

The one area where Gold Standard surpasses its ON relative is with its unique fat blend including 11 grams of healthy fats from flaxseed, chia, and MCTs. Healthy fats are extremely important for overall health. When it comes to bulking up, healthy fats like MCT oil can actually keep the amount of fat you gain in check. This is critical when your goal is muscle, not fat mass. (7)

 

Cons of Optimum Nutrition Gold Standard Gainer

Aside from the usual use of artificial sweeteners and flavouring, there isn't much you can argue against when it comes to Gold Standard Gainer. The only 'issue' is that the protein blend is primarily made of Whey Isolate, which means fast digesting amino acids. You can use it during any point in the day but especially following a workout.

 

Which One Should You Buy?

What you have here is two great mass gaining products. There is no denying that Gold Standard Gainer has the superior quality of the two products; however, it also has the bigger price tag. We would say that the extra money is well worth it but if you need to watch your spending this month, Pro Gainer is an excellent mass gaining choice.

 

References

1. Tsutsumi R, Tsutsumi YM. Peptides and proteins in whey and their benefits for human health. Austin J Nutri Food Sci 2014;1(1): 1002

 

2. Blomstrand E, Eliasson J, Karlsson HK, Köhnke R. Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise. J Nutr. 2006 Jan;136(1 Suppl):269S-73S.

 

3. Norton, Layne, Layman, Donald. Leucine Regulates Translation Initiation of Protein Synthesis in Skeletal Muscle after Exercise. J. Nutr. February 2006 vol. 136 no. 2 533S-537S.

 

4. Negro M, Giardina S, Marzani B, Marzatico F. Branched-chain amino acid supplementation does not enhance athletic performance but affects muscle recovery and the immune system. J Sports Med Phys Fitness. 2008 Sep;48(3):347-51.

 

5. Mourier A, Bigard AX, de Kerviler E, Roger B, Legrand H, Guezennec CY. Combined effects of caloric restriction and branched-chain amino acid supplementation on body composition and exercise performance in elite wrestlers. Int J Sports Med. 1997 Jan;18(1):47-55.

 

6. De Lorenzo A, Petroni ML, Masala S, Melchiorri G, Pietrantuono M, Perriello G, Andreoli A. Effect of acute and chronic branched-chain amino acids on energy metabolism and muscle performance. Diabetes Nutr Metab. 2003 Oct-Dec;16(5-6):291-7.

 

7. St-Onge MP, Bosarge A. Weight-loss diet that includes consumption of medium-chain triacylglycerol oil leads to a greater rate of weight and fat mass loss than does olive oil. Am J Clin Nutr. 2008 Mar;87(3):621-6.

Pre-workout supplements can potentially be the difference between owning your workouts and never showing up. After a long and busy day, it can be tough to muster up the motivation to crank out an hour session at the gym. This is why pre-workouts have become so immensely popular. One of the biggest names in the industry, German American Technologies, has produced two incredible, tried and true pre-workout supplements: GAT PMP vs. GAT Nitraflex. Let's review these two products to see which is really worth having at home.

 

GAT PMP

Where can I buy it?

• Here's where you can buy GAT PMP .

 

Pros of GAT PMP

GAT's Peak Muscle Performance (PMP) is the pre-workout that put the company on the map. It isn't just a shot of caffeine with some random vitamin complex; this is a multi-level pre-workout that will deliver the energy you're looking for.

 

The team over at GAT has broken down what the supplement offers into four easy-to-understand categories:

 

• Nitric Oxide Enhancers
• Pump Accelerators
• Focus & Cognition Modulators
• Energetics

 

The ingredients found in the first two categories, which include L-Citrulline Malate, Beta-Alanine, and Calcium Lactate may help to increase nitric oxide production in the body allowing for insane pumps, more strength, better recovery, and faster removal of lactic acid build-up.

 

As for energy and intense focus, that's exactly what you'll be getting from the latter categories. Each serving hits you with 325 mg of caffeine. Mix that with N-Acetyl L-Tyrosine and L-Theanine and what you have is laser sharp focus and an unstoppable amount of energy.

 

Working together, all of these ingredients are going to help you crush your workout and have plenty of energy leftover. (1-3)

 

Cons of GAT PMP

Outside of artificial sweeteners and flavouring, the only issue we had with GAT's PMP is the fact that you aren't sure exactly how much of each ingredient you are getting. You get the grams for each blend but that could mean one ingredient far outweighs the others. This is important as each of these ingredients dose have a recommended dose for maximum benefits but you'll never know if you're getting it.

 

 

GAT Nitraflex

Where can I buy it?

• Here's where you can GAT Nitraflex.

 

Pros of GAT Nitraflex

GAT seems to be a fan of breaking down each ingredient into a quick category and Nitraflex is no exception. Nitraflex has three ingredient categories:

 

• Vascoactive Arginase-Regulating NO Precursor Complex
• Acute Energy, Focus, Intensity, Neuromodulating, Endurance Complex
• Clinically-Studied Testosterone-Enhancing Complex

 

Just like with PMP, Nitraflex offers you an N.O. boosting blend. The difference is that Nitraflex has the upper hand here. It offers you AAKG and L-Arginine, both of which are the top N.O. boosters in the industry.

 

Moving on to energy and focus, Nitraflex is ready to deliver. It offers you a really intense blend of energy boosters, thermogenics, and nootropics including DMAE Bitrartrate, Theanine, and Rauwolscine. DMAE has been shown to be a powerful focus enhancer. Combine that with Rauwolscine, an energy booster related to Yohimbine, and caffeine are you're looking at an elite pre-workout supplement.

 

Lastly, GAT threw in a Clinically-Studied Testosterone-Enhancing Complex featuring the ingredient Calcium fructopyranose borate, which may be able to support natural production of testosterone. (3-5)

 

Cons of GAT Nitraflex

Downsides to Nitraflex are twofold:

 

First, with its testosterone support ingredient, the supplement is limiting its market to a male audience (Women use pre-workouts too, guys).

 

Second, Nitraflex has a stimulant packed energy blend. For some, this will be exactly what the supplement guru ordered. For others who are not accustomed to using energy boosters, these stimulants can put a serious hurt on the body. You may want to assess your tolerance with half a serving then build up accordingly.

 

Which One Should You Choose?

Both of these pre-workouts are top notch. The difference really comes down to two things:

 

Are you a woman? If so, you'll want to go with PMP as it's free of testosterone boosters.

 

Do you have a high caffeine / stimulant tolerance? If so, Nitraflex is going to be able to deliver hardcore energy with intense focus. PMP has plenty of caffeine but Nitraflex has the better nootropic blend.

 

References

1. Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012 Jul;43(1):25-37. doi: 10.1007/s00726-011-1200-z. Epub 2012 Jan 24.

2. Westerterp-Plantenga MS, Lejeune MP, Kovacs EM. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Obes Res. 2005 Jul;13(7):1195-204.

3. F. L. Dodd, D. O. Kennedy, L. M. Riby, and C. F. Haskell-Ramsay. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology. 2015; 232(14): 2563–2576. Published online 2015 Mar 13.

4. Caille E.-J. Study concerning the bisorcate demanol effects upon quantified EEG, cortical vigilance and mood. Comparative double-blind, cross-over balanced design versus pirisudanol. Psychol Med. 1986;18:2069-2086.

5. Ostojic SM. Yohimbine: the effects on body composition and exercise performance in soccer players. Res Sports Med. 2006 Oct-Dec;14(4):289-99.

Pre-workouts are the staple of the fitness world, right alongside protein, and the best companies understand that means more than just throwing some caffeine in a brightly coloured powder. Let's take a look at two of the biggest names in the pre-workout world, Optimum Nutrition Gold Standard Pre-Workout and Cellucor C4, to see which one should be sitting on your shelf.

 

Optimum Nutrition Gold Standard Pre-Workout

Where can I buy it?

• Click here to buy Optimum Nutrition Gold Standard Pre-Workout.

 

Pros of Optimum Nutrition Gold Standard Pre-Workout

Optimum Nutrition rarely disappoints and their Gold Standard Pre-Workout is no exception. Gold Standard is a perfect blend of energy boosters and nootropics to help get you in the zone before a workout.

 

Sure, it contains caffeine but it doesn't overdo it like some of those over-the-top pre-workouts. At 175 mg per serving, that's a nice and steady kick that's backed up by a number of other ingredients including Beta Alanine, Gingseng, and N-Acetyl-L-Tyrosine. Gold Standard is free of controversial stimulants like Yohimbe and instead focuses on a level-headed way to boost your energy levels. (1)

 

Cons of Optimum Nutrition Gold Standard Pre-Workout

Gold Standard's pros may be its cons, depending on who you are. For the supplement newbie or those sensitive to energy boosters, Gold Standard is going to be the perfect pre-workout. For those who have taxed and maxed out their adrenal systems, Gold Standard may not even get you to baseline.

 

 

Cellucor C4

Where can I buy it?

• Click here to buy Cellucor C4.

 

Pros of Cellucor C4

Cellucor C4: Is there anyone who doesn't know the name of this pre-workout? C4 has been around the block time and again. In fact, Cellucor has released a series of C4 spin-off products including C4 Ripped and C4 Extreme. Today, let's focus on the classic formula.

 

As far as energy goes, C4 can't be beat. We love the combination of Velvet Bean with Caffeine and Theacrine. Studies show that when you mix Caffeine with Theacrine, you can avoid the classic jitters and instead focus on the energy boosting. What's a workout without a pump? C4 has long been one of the best nitric oxide blends featuring Creatine Nitrate and AAK (Arginine Alpha Ketoglutarate), which are two of the most used N.O. boosters on the market. (1-3)

 

Cons of Cellucor C4

We love C4; however, what we don't like is mystery. That's what you get with C4's proprietary blend, which makes it impossible to know exactly how much of each ingredient you are getting in the energy blend. With that said, seeing as how C4 is still a fan favourite, it's a safe bet that you are getting a high enough dose of the energy boosting formula to crush your workout.

 

Conclusion

Optimum Nutrition Gold Standard Pre-Workout and Cellucor C4 are both amazing products and they are giants in the industry for a reason. Both offers formulas that kickstart energy levels, support performance, and enhance any workout. The deal breaker is going to be how much of a caffeine tolerance you have. If you need several cups of coffee just to get you started in the morning, we would recommend C4. If you've never experimented with pre-workouts before, go with Gold Standard.

 

References

1. Westerterp-Plantenga MS, Lejeune MP, Kovacs EM. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Obes Res. 2005 Jul;13(7):1195-204.

2. Daniel J. Kuhman, Keanan J. Joyner, and Richard J. Bloomer. Cognitive Performance and Mood Following Ingestion of a Theacrine-Containing Dietary Supplement, Caffeine, or Placebo by Young Men and Women. Nutrients. 2015 Nov; 7(11): 9618–9632.

3. Elfego Galvan, Dillon K. Walker, Sunday Y. Smbo, Ryan Dalton, Kyle Levers, Abigail O'Connor, Chelsea Goodenough, Nicholas D. Barringer, Mike Greenwood, Christopher Rasmussen, Stephen B. Smith, Steven E. Riechman, James D. Fluckey, Peter S. Murano, Conrad P. Earnest and Richard B. Kreider. Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance. Journal of the International Society of Sports Nutrition201613:12. DOI: 10.1186/s12970-016-0124-0.

Making the most out of your fitness routine may be a lot easier with the help of a pre-workout supplement. A pre-workout is a supplement taken before you hit the weights, track, or pool to help you increase your performance. Thus, you'll be cashing in on the maximum benefit from your exercise routine. While there are many pre-workout supplements out there, we are going to compare two of the most popular ones: Cellucor CN3 vs. GAT Nitraflex.

 

Cellucor CN3

Where can I buy it?

• Here's where you can buy Cellucor CN3.

 

Pros of Cellucor CN3

Cellucor makes some of the best pre-workout products you'll find on the market and one of their most popular is CN3. It is made up of only two ingredients: 3 grams of Creatine Nitrate and 500 mg of Vitamin C. Together, this combination may be an effective way to boost nitric oxide levels for peak performance.

 

If you're looking to build muscle or if your exercise regimen is made up largely of strength training, Cellucor CN3 may be very beneficial. This supplement is a Nitric Oxide Booster, also known as an N.O. Booster, and its primary function is to provide your muscles with oxygen and blood flow. The increased flow and pump of oxygen helps to boost performance during your workout. A side bonus is that insane vein-bulging 'pump' that many lifters report feeling. CN3 may be able to support gains in strength levels and intra-workout performance. (1)

 

Cons of Cellucor CN3

This is a straight-shooting product. It doesn't claim to be an insane pre-workout energy enhancer; rather, it's there to support nitric oxide and performance levels. The only downside to Cellucor CN3 may be the use of artificial flavours and sweeteners but other than that, you're getting a solid N.O. booster.

 

 

GAT Nitraflex

Where can I buy it?

• Here's where you can GAT Nitraflex.

 

Pros of GAT Nitraflex

Nitraflex is an extremely potent pre-workout supplement by German American Technologies (GAT). The product enhances energy and strength alike while potentially supporting healthy testosterone production as well.

 

Nitraflex includes 3 hard-hitting main ingredients: DMAE, Caffeine, and Beta Alanine. Together, these ingredients work to provide higher energy levels and a larger intra-workout pump. At 325 mg of Caffeine per serving, you'll never feel fatigue during or after your workout.

 

The formula of Nitraflex hits your energy needs from all sides: you're getting hardcore stimulants along with nootropics for focus and even some thermogenics, which may support fat burning. All in all, this is an all-around great pre-workout to start your lifting session with. (2-4)

 

Cons of GAT Nitraflex

Downsides to Nitraflex are dependent upon how you react to stimulants. DMAE combined with Caffeine (not to mention the Rauwolscine you're getting) has been known to pack a powerful punch, especially if you don't tolerate stimulants well. You may want to assess your tolerance with half a serving then build up accordingly.

 

Other than that, this pre-workout is going to be the one-two punch you need to kick away fatigue and get busy in the gym.

 

Which One Should You Choose?

Here's the thing: Both CN3 and Nitraflex are pre-workouts; however, they are in two radically different categories of pre-workouts. CN3 is a nitric oxide booster while Nitraflex is an energy amplifier and nootropic. The good news: You can (and should) use them together.

 

References

1. Elfego Galvan, Dillon K. Walker, Sunday Y. Simbo, Ryan Dalton, Kyle Levers, Abigail O'Connor, Chelsea Goodenough, Nicholas D. Barringer, Mike Greenwood, Christopher Rasmussen, Stephen B. Smith, Steven E. Riechman, James D. Fluckey, Peter S. Murano, Conrad P. Earnest and Richard B. Kreider. Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance. Journal of the International Society of Sports Nutrition201613:12. DOI: 10.1186/s12970-016-0124-0.

2. Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012 Jul;43(1):25-37. doi: 10.1007/s00726-011-1200-z. Epub 2012 Jan 24.

3. Westerterp-Plantenga MS, Lejeune MP, Kovacs EM. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Obes Res. 2005 Jul;13(7):1195-204.

4. Caille E.-J. Study concerning the bisorcate demanol effects upon quantified EEG, cortical vigilance and mood. Comparative double-blind, cross-over balanced design versus pirisudanol. Psychol Med. 1986;18:2069-2086.