Cold water immersion (a.k.a., “ice baths”) has become a popular method amongst exercise enthusiasts and athletes to enhance recovery after an intense training bout. The strategy involves exposing either the trained limb or the whole body to very cold liquid temperatures. According to p...
Brad Schoenfeld, Ph.D, C.S.C.S., is an internationally renowned fitness expert and widely regarded as one of the leading authorities on body composition training (muscle development and fat loss). He is a lifetime drug-free bodybuilder, and has won numerous natural bodybuilding titles.
I recently was asked to write a paper for the NSCA Hot Topic series, and decided to address one of the most controversial subjects in the fitness field: namely, are full squats bad for your knees? As I detailed in the article, the answer is no, deep squats do not pose increased risk of injury to the knees *provided* you have no existing knee issues. Without question, deep squats may be contraindicated for those with knee pathology depending on the extent of the injury (it should be noted that any exercise may contraindicated because of injury). If you fall into this category, a qualified physician specializing in sports medicine should be able to assess what you can and can’t do. Otherwise, squat depth should not be an issue from an injury perspective. In fact, the deeper range of the squat is actually protective of many of the knee structures!
Assuming you have healthy knee function, what you should in fact consider with respect to squat depth are your goals. Deep squats have relevance to various sports, as well as many activities of daily living. These are powerful reasons why you would be well served by squatting as low as possible, at least on some of your sets. What’s more, glute involvement increases the lower you go in a squat. This means that if you want to maximize the development of your butt, then deep squats are highly beneficial. On the other hand, quadriceps development is greatest squatting to parallel. So if you are most concerned with developing your frontal thighs, deep squats might not be a necessity.
The bottom line is, don’t be afraid to squat low as long as you don’t have any existing knee problems. Make a decision based on your goals, not fear of injury. If you’re interested in reading about the science on the topic, you can check out my Hot Topic article at the link below.
In previous blog posts, I’ve addressed the importance of resistance training in reducing body fat and maintaining weight loss. You may remember that this was a hot topic over the summer in my rebuttal to the Time Magazine article on whether exercise is beneficial for losing weight. Now comes yet more evidence to back up these claims.
In a study published in the prestigious journal Medicine and Science in Sports and Exercise, a research group led by Jennifer Bea evaluated the effects of strength training on 122 postmenopausal women over the course of a 6-year period. All of the women had been previously sedentary. At the beginning of the study, 65 of the women were placed in an exercise program consisting of various strength training training exercises including squats and presses. A year into the study, 32 of the remaining non-exercisers were placed on the exercise program, leaving 25 of the women to serve as controls who did not exercise throughout the entire period studied. What was the outcome? As you may have guessed, strength training had a positive effect on weight management. Specifically, both exercise frequency and the amount of weight lifted were inversely associated with weight gain (i.e. those who exercised more and lifted more had lower body weights). On the whole, those who lifted were significantly leaner than those who didn’t.
For anyone who has read this blog, these results should not come as a surprise. The metabolic benefits attributed to lifting weights have been well documented. Not only is there a significant caloric cost associated with strength training (provided rest intervals are limited and sets are sufficiently challenging), but it also increases excess post-exercise oxygen consumption (i.e. the “afterburn”) so that calorie burning continues for up to 38 hours or more after a workout. Further, muscle itself is a metabolically active tissue that serves to keep your metabolism stoked round the clock. By increasing muscle development, strength training indirectly promotes better weight management.
Bottom line: An exercise program aimed at weight loss should always have a strength training component. While aerobic exercise certainly will help to expedite fat loss, nothing replaces lifting weights for enhancing fat burning and, more importantly, keeping the weight off over the long term. Lift to lose!
Stay Fit!
Brad
Reference:
Bea JW, Cussler EC, Going SB, Blew RM, Metcalfe LL, Lohman TG. Resistance Training Predicts Six-Year Body Composition Change in Postmenopausal Women. Med Sci Sports Exerc. 2009 Dec 14.
Set foot in any gym and you’ll no doubt see cardio machines that have charts to help you train in your ‘fat burning zone’. The theory behind the concept is based on studies showing that the percentage of fat used as an energy source is optimized when you train at an intensity between 60 to 80 percent of your target heart rate. But while increasing the percentage of fat burned for fuel sounds like a great way to get lean, it unfortunately doesn’t translate into burning more fat on an absolute basis. The most important aspect of shedding body fat is the total amount of calories burned—not the percentage of calories from fat—and therefore a higher intensity cardio routine is the better choice.
You see, the human body is a dynamic organism and constantly adjusts its use of fat for fuel. This process is governed by a host of factors (including enzyme levels, substrate availability, internal feedback loops, etc.). If you expend more calories than you consume, your body will shift to a fat burning mode and mobilize excess adipose as a source of energy. Thus, from a fat loss perspective, high-intensity exercise burns more fat calories on an absolute basis than lower intensity activities.
Ideally, the activity that maximizes calorie burning is interval training, where short bouts of low intensity exercise are interspersed with high intensity bouts. Interval training not only heightens fat burning during the activity itself, but also increases the amount of calories you burn after the workout is over! This is due to a phenomenon called excess post-exercise oxygen consumption (EPOC). Simply stated, EPOC keeps your metabolism elevated for several hours following training. Moreover, there is an associated increase in the secretion of both growth hormone and noradrenaline—hormones that are integrally involved in the fat burning process—resulting in an increased utilization of fat of fuel. All told, there is both a greater total amount of calories expended as well as a greater amount of fat oxidation following training.
Here’s the catch, though: EPOC is intensity dependent—the harder you train, the more calories you expend following training. That’s why you need to push yourself as hard as you can during your high-intensity intervals, going as close to all-out as possible. For those who have never performed this type of cardio, I generally recommend starting out with an interval ratio of 4:1 (i.e. four minutes at low intensity followed by 1 minute at high intensity) and, as you become more fit, gradually lower the ratio until you are at 1:1.
Although people tend to associate interval training with treadmill exercise, virtually any cardiovascular activity can be employed, including machines such as the stair climber, elliptical machine, and stationary bike. You can also jump rope or perform any number of outdoor activities, too. Just make sure that you are readily able to switch between high and low intensities. In final analysis, you’ll exert a good deal more effort in your training, but the results will be well worth it!
Schoenfeld, B., Dawes, J. (2009). High-Intensity Interval Training: Applications for General Fitness Training. Strength and Conditioning Journal, 31(6), 44-46
It’s pretty much common knowledge by now that consumption of fish oil provides a wide range of health-related benefits. These benefits extend to almost every organ system imaginable and include the prevention of numerous disease states. There is even some evidence that fish oil aids in fat loss, helping to keep you lean by simply replacing other fats in the diet on a calorie-for-calorie basis (8). The body of research showing positive effects is so compelling that it seems almost too good to be true.
The benefits of fish oil can be traced to two compounds: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Rather than bore you with technical details as to their mechanisms of action, I’ll just say that EPA and DHA regulate various genes in the body, particularly those involved in inflammatory processes and energy metabolism. The fat in certain fish species act as a storehouse of “preformed” EPA and DHA that is readily used by the human body after consumption. You can obtain these compounds by eating various cold water fish species (such as salmon, mackerel, and sardines), or by consuming fish oil supplements in either liquid or capsule form. Simple enough.
Some people, however, are averse to consuming fish and their oils. Vegetarians, in particular, fall into this category. Others simply don’t care for the taste of fish and find that supplements don’t digest well. So the question then arises whether a vegetable source is available that provides the same benefits as fish oil.
Flaxseed oil is often touted as a vegetable-based alternative to fish oil. Unlike fish oil, flax does not contain preformed EPA or DHA. Rather, it possesses a compound called alpha-linolenic acid (ALA) that can be converted to EPA and DHA in the body. This is where things start to get murky…
In order for conversion of ALA to take place, it must undergo a complex process that further “desaturates” the fatty acid and correspondingly forms longer chain polyunsaturated derivatives. Problem is, research shows that this conversion process is rather inefficient. A review article by Canadian researchers Mélanie Plourde and Stephen Cunnane (7) estimated that only 5% of ALA is converted to EPA and that less than 0.5% of ALA is converted to DHA.
With respect to EPA, the news is not as bad as it sounds. A recent study by Dr. Gwendolyn Barceló-Coblijn (3) and colleagues showed that consumption of 2.4 grams of flax oil increased EPA levels in red blood cells by 1.4-fold — an amount comparable to supplementation with 0.6 grams of fish oil (although less than that found with supplementation of 1.2 grams of fish oil). Similarly, a group of researchers at Emory University led by Dr. Charles Harper (5) found that supplementing with 3 grams of ALA derived from flax oil increased blood levels of EPA by 60%. However, neither study noted any changes in blood levels of DHA. This is significant in that DHA appears to be the more biologically important of the two. DHA is believed to be particularly necessary for brain function, as well as eye health. So the fact that ALA is poorly converted to DHA seemingly makes flax oil a poor substitute for fish oil.
Now before drawing any final conclusions on the matter, a couple of things need to be considered. First, none of the studies evaluated the subject’s consumption of omega-6 fats. Why is this relevant? Well, omega-6 fats compete with omega-3s for desaturation. If there is an abundance of omega-6s in the diet, then conversion of omega-3s will be reduced. And in the Western world, the average ratio of omega-6 to omega-3 is well in excess of 20:1! Thus, it’s possible that if you reduce the ratio to a more palatable 4:1, a greater DHA conversion would be seen.
What’s more, the studies in question looked at the levels of DHA in the plasma and red blood cells — not in specific tissues that require DHA. It is possible that tissues such as the brain, retina, and kidneys use ALA to manufacture DHA as needed, and this would not show up in tests of the blood.
What’s more, it is quite possible that ALA may confer other benefits over and above those found in EPA and DHA. Multiple studies have shown that consumption of ALA itself has cardioprotective effects (2, 4, 6). Further, as noted in the study by Barceló-Coblijn (3), ALA antagonizes the synthesis of arachidonic acid, which is a pro-inflammatory that can negatively impact the body. This alone may possibly aid in preventing various disease states.
Moreover, flax oil contains compounds called lignans that are not present in fish oil. Lignans have been shown to possess antioxidant properties and produce anti-estrogenic effects that may provide a host of additional health-related benefits, including a reduced risk of various cancers (1).
Bottom line: At this point it seems that fish oil probably contains unique properties that are not obtainable in flax. Therefore, until research shows otherwise, flax oil should not be considered a substitute for fish oil. However, flax may provide additional benefits over and above those found in fish oil, and could have an additive effect when the two are consumed in combination.
Stay Fit!
Brad
1. Adolphe JL, Whiting SJ, Juurlink BH, Thorpe LU, Alcorn J. Health effects with consumption of the flax lignan secoisolariciresinol diglucoside. Br J Nutr. :1-10.
2. Ascherio A, Rimm EB, Giovannucci EL, Spiegelman D, Stampfer M, Willett WC. Dietary fat and risk of coronary heart disease in men: cohort follow up study in the United States. BMJ1996;313:84–90.
3. Barceló-Coblijn G, Murphy EJ, Othman R, Moghadasian MH, Kashour T, Friel JK. Flaxseed oil and fish-oil capsule consumption alters human red blood cell n-3 fatty acid composition: a multiple-dosing trial comparing 2 sources of n-3 fatty acid. Am J Clin Nutr. 2008 Sep;88(3):801-9.
4. de Lorgeril M, Renaud S, Mamelle N, et al. Mediterranean alpha-linoleic acid-rich diet in secondary prevention of coronary heart disease. Lancet 1994;343:1454–9.
5. Harper CR, Edwards MJ, DeFilippis AP, Jacobson TA. Flaxseed oil increases the plasma concentrations of cardioprotective (n-3) fatty acids in humans. J Nutr. 2006 Jan;136(1):83-7.
6. Hu FB, Stampfer MJ, Manson JE, et al. Dietary intake of alpha-linoleic acid and risk of fatal ischemic heart disease among women. Am J Clin Nutr1999;69:890–7.
7. Plourde M, Cunnane SC. Extremely limited synthesis of long chain polyunsaturates in adults: implications for their dietary essentiality and use as supplements. Appl Physiol Nutr Metab. 2007 Aug;32(4):619-34
8. Schoenfeld, B. (2004) Omega-3 Fatty Acids: A Novel Fat Burner. Strength and Conditioning Journal, 26(3), 72–76
Wanted to share a motivational blog with you, Finding Radiance. The blogger, Lori, lost 105 pounds with the help of my book, 28 Day Body Shapeover. Kudos to Lori for adopting a fitness lifestyle–she’s a true fitness inspiration! The fact that I was able to help in the process is what makes my life’s work worthwhile.
For those of you in the NY area, I will be appearing this Sunday, January 17, on Today in New York (NBC). The topic will be effective home workout strategies. Hope you can tune in!
Just wanted to extend a big thanks to all who attended my book signing for Women’s Home Workout Bible at Borders Books in Mt. Kisco, and helped to make the event a success. For those who couldn’t make it, here’s a photo from the event.
Those familiar with my teachings know that I’m a big proponent of establishing a mind-to-muscle connection when performing resistance exercise. I’ve gone into extensive detail in my books on exactly how to incorporate mind-to-muscle training during the course of a workout. Now, a recent study published in the prestigious Journal of Strength and Conditioning Research shows just how effective the technique can be. Using a technique called EMG that measures the electrical activity of muscles during exercise, researchers found that focusing on latissimus dorsi (i.e. a large back muscle) significantly increased its activity during performance of the lat pulldown. This has major implications if you’re trying to optimize body composition.
Understand that strength training is not simply the act of lifting a weight from Point A to Point B. Rather, you must concentrate on the target muscle(s) that you’re working and channel your efforts into making those muscles exert the required force to execute the lift. Otherwise, secondary muscle movers are bound to dominate during performance, reducing activity of the target muscle.
Now this doesn’t mean you’ll isolate the target muscles — complete muscular isolation is a near impossibility during traditional strength training. But you will maximize the work performed by the intended muscles, thus optimizing their development. If you don’t already use the technique, I urge you to give it a try. No doubt it will improve your results — guaranteed.
Stay Fit!
Brad
Snyder BJ, Leech JR. Voluntary increase in latissimus dorsi muscle activity during the lat pull-down following expert instruction. J Strength Cond Res. 2009 Nov;23(8):2204-9.
Entries (RSS)
