Archive for May, 2011
Ok that’s the cheesiest blog title ever…. but here’s another study:
Med Sci Sports Exerc. 2011 Apr;43(4):624-31
Exercise Intensity Influences NEAT in Overweight and Obese Adults.
Alahmadi M et al.
The researchers compared “non exercise activity thermogenesis” (basically all the calories we burn unrelated to exercise, sleeping or eating) in two groups following exercise: A medium intensity exercise group and a high intensity interval exercise group.
The moderate group walked at a constant pace of 6km per hour. The high intensity group walked at 6km/h at 10 degree inclines for 5 mins, followed by a recovery period of 5 mins at 5kmh and zero degrees. I’m not sure I would call that “High” intensity but it’s definitely higher than the other group. Both groups exercises for one hour.
Here’s the interesting thing – there was no difference in non-exercise activity for two days following the training. However on the third day afterwards, the high intensity exercise group had a 25% higher NEAT compared to the exercise day, and 30-33% higher than pre-exercise days. The medium intensity group showed no change.
So the higher intensity group actually moved more three days after training than the medium intensity group. For whatever reason, (the mechanism that regulates NEAT is unknown), the higher intensity program not only burned more calories during training, but actually had people move 25% more than they did outside of the exercise session on the training day and 33% more than usual a few days after.
My interpretation: we know that higher intensity exercise burns more calories during exercise. We also know that high intensity exercise burns more calories after exercise (through EPOC and anaerobic calorie burns). Now we know that for some reason it also increases non-exercise activity thermogenesis VERY significantly.
The researchers noted “A longer-term intervention is needed to determine the effect of accumulated exercise sessions over a week on NEAT.”
A lot of researchers/internet writers have speculated that higher intensity exercise would leave people too tired to move much afterwards, and perhaps result in them burning less calories overall as a result. This study (while not really “high intensity” in my opinion) actually showed the opposite – people moved more.
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AC
Tags: Here’s a few fat loss related studies I’ve been reviewing recently:
Friedenreich et al.
Adiposity changes after a 1-year aerobic exercise intervention among postmenopausal women: a randomized controlled trial
Int J Obes (Lond). 2011 Mar;35(3):427-35
This study put 320 women on a one year program. There were two groups – an exercise group and a control group. The exercise group was instructed to perform 45 mins of moderate to vigorous aerobic exercise five times per week (and over the course of the year, they averaged 3.6 training sessions per week or 178 mins per week). Both groups were asked to keep their diets the same.
Results: The aerobic group lost 3.9lbs more fat than the control group over the year.
My interpretation/comments: no surprises to regular readers of my blog, I don’t think aerobic exercise is a very useful fat loss tool.
Zakrzewski et al.
Comparison of fat oxidation over a range of intensities during treadmill and cycling exercise in children.
Eur J Appl Physiol. 2011 Apr 21.
Results: This study showed that fat oxidation was higher in treadmill exercise than cycling exercise over a range of absolute and relative exercise intensities. Which means that treadmill exercise, even at the same intensity as cycling, results in higher fat burning and could result in faster fat loss in programming.
My interpretation/comments: We’ve seen in calorie matched studies that weight training outperforms aerobic exercise in terms of fat loss. This is one of a few studies to compare treadmill and cycling in terms of fat oxidation (A 2003 study in Metabolism, and a 2010 study in the International journal of sport nutrition and exercise metabolism) – although it’s the first one to look at children..
My interpretation is that the difference is a result of running being more weight bearing than cycling, so “weight bearing” or “ground based” activities at the same intensity will be more effective in fat loss training.
Effect of Diet and Exercise, Alone or Combined, on Weight and Body Composition in Overweight-to-Obese Postmenopausal Women.
Obesity (Silver Spring). 2011 Apr 14. [Epub ahead of print]
439 obese women were split into four groups – diet only, aerobic exercise only, diet plus aerobic exercise and a control group.
My interpretation: Diet is obviously the key factor in fat loss, and this study confirms that, and shows once again that aerobic exercise doesn’t seem to provide much direct benefit in fat loss, in the absence of diet. Adding aerobic exercise to the diet only resulted in an increase in 2.3% of weight loss over the course of a year.
Exercising fasting or fed to enhance fat loss? Influence of food intake on respiratory ratio and excess postexercise oxygen consumption after a bout of endurance training.
Int J Sport Nutr Exerc Metab. 2011 Feb;21(1):48-54.
Two groups in a crossover study (meaning all participants did both protocols). Food intake was the same overall, the only difference was performing endurance cardio either fasted or after breakfast.
Calorie burning was higher after the fed training session, both 12 and 24 hours after the training session when compared to the fasted state.
“The authors conclude that when moderate endurance exercise is done to lose body fat, fasting before exercise does not enhance lipid utilization; rather, physical activity after a light meal is advisable.”
Direct hits to the head during amateur boxing is associated with a rise in serum biomarkers for brain injury.
Int J Immunopathol Pharmacol. 2011 Jan-Mar;24(1):119-25.
My interpretation: We didn’t know this? Really?
Ok – Getting punched in the head isn’t good for you in case you didn’t know.
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AC
