For our purposes here, high-intensity cardio falls between about 80 to 90 percent of your maximum heart rate (MHR) or, if you're not using heart rate zones, about a 6 to 8 on a 10-point perceived exertion scale. What this translates to is exercise at a level that feels challenging and leaves you too breathless to talk in complete sentences. But you're not going all out, as in sprinting as fast as you can. There's no doubt that some high-intensity training work can be helpful for weight loss as well as improving endurance and aerobic capacity.
While that can certainly be a worthwhile endeavor, what they usually really mean to say is, “I want to lose fat.” Though most people use the terms weight loss and fat loss interchangeably, they are not in fact the same, and require different methods to achieve each goal. Here, we explain why fat loss — not weight loss — should be your primary focus, and why the typical methods used for weight loss may not always work for fat loss efforts.
As for carb choices, the aforementioned bagel should be 100% whole wheat, not white. At all times during the day, in fact, choose whole-grain foods over refined ones, the only exception being immediately after a workout, when fast-digesting carbs reign supreme for boosting insulin and replenishing muscle glycogen stores (see Law 8). Keep carbs to less than 2g per pound of bodyweight per day.
While the Duke study found no added benefit to resistance training (aka weight or strength training) when it comes to belly fat, a 2014 study from a Harvard University team found otherwise. Twenty minutes of weights a day was linked to less of an increase in belly fat (particularly for older men). “Engaging in resistance training or, ideally, combining it with aerobic exercise could help older adults lessen abdominal fat while increasing or preserving muscle mass," said the paper’s lead author Rania Mekary.
This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.