The world of exercise science is constantly changing for the better, no longer are will limited to “testimonial’s” from the most ripped guy in the gym for advice. Back when I started lifting weights, just about every person that was dieting was doing cardio in a fasted state. Some athletes swear by fasted cardio for fat loss whereas others say it’s not only ineffective but harmful as well.
On of the biggest risks for training on a empty stomach is the rise in cortisol which accelerates muscle tissue breakdown which may be considered counterproductive for lean muscle mass. The key is to enhance fat loss without losing excess muscle mass. With fat loss in mind, you will have to minimize calories and while trying to deplete muscle glycogen levels to burn more fatty acids during exercise and rest.
For example, when a person is fasting, such as sleeping and between meals, more fat is being burned. If your trying to lose fat, than HMB may be the perfect supplement to take to prevent catabolism while doing fasted cardio.
β-Hydroxy-β-methylbutyrate (HMB), is a leucine-derived metabolite, has been demonstrated to augment strength and lean muscle gains when supplemented in conjunction with resistance training. HMB has been found to have potent anticatabolic properties. When leucine and HMB were compared, it appears that leucine performed better in muscle protein synthesis but HMB performed better in preventing muscle protein breakdown. Recently, an 18% increase in strength gain was demonstrated following 12 weeks of HMB ingestion compared to placebo in experienced resistance trained men.
HMB is not just for strength gains, but also has been shown to result in significant fat loss. One study examined twenty-eight volunteers took either three grams of HMB or a placebo, and strength-skilled six days a week for 7 weeks. By the finish of the review time period, the HMB-takers had lost twice as considerably body unwanted fat as people taking the placebo.
A study in the Journal of Exercise Science and Fitness reported that HMB also enhanced fat loss. Taiwanese researchers put women on a diet. The women’s diet contained 3.6 g carbohydrates, 1.33 g protein and 0.03 g fat per kg bodyweight. They also took a multivitamin supplement. Half of the women were also given 3 g HMB per day to take: 1 g each at breakfast, lunch and supper. The other half was given a placebo. At the end of the study, bodyfat percentage in the HMB group went down from 20.23 percent to 19.38 percent. Researchers estimate that the women in the HMB lost an average of about 700 g fat.
Another study reported that HMB can enhance fat loss in older men. Researchers examined the effects of 12-weeks of HMB ingestion and resistance training (RT) on abdominal adiposity were examined in 48 men (66-78 yrs). All participants were randomly assigned to 1 of 4 groups: no-training placebo, HMB only, RT with placebo, or HMB with resistance exercise. At the end of the study, the group taking HMB and resistance training had significant losses in abdominal bodyfat.
The good thing about HMB supplementation, is that it does not raise insulin levels as opposed to leucine, so it may be the perfect supplement to take during fasted cardio whereas leucine has pronounced effects on raising insulin, so the HMB maybe the perfect supplement to take before fasted cardio as its anti-catabolic and it does not raise insulin levels. Taking leucine after exercise may be preferable as its anabolic and can raise insulin post-exercise.