When you do high-intensity interval training (and if you’re not, you should be!), follow a 2:1 work-to-rest ratio, such as sprinting one minute followed by 30 seconds of recovery. [Tweet this secret!] According to several studies, the most recent out of Bowling Green State University, this formula maximizes your workout results. The BGSU researchers also say to trust your body: Participants in the study set their pace for both running and recovery according to how they felt, and by doing so women worked at a higher percentage of their maximum heart rate and maximum oxygen consumption than the men did.
Popular belief says if you really want to make a big change, focus on one new healthy habit at a time. But Stanford University School of Medicine researchers say working on your diet and fitness simultaneously may put the odds of reaching both goals more in your favor. They followed four groups of people: The first zoned in on their diets before adding exercise months later, the second did the opposite, the third focused on both at once, and the last made no changes. Those who doubled up were most likely to work out 150 minutes a week and get up to nine servings of fruits and veggies daily while keeping their calories from saturated fat at 10 percent or less of their total intake. 
In the past, women have often tried to make up deficits in their diet though the use of vitamins and supplements. However, while supplements can be a useful safeguard against occasional nutrient shortfalls, they can’t compensate for an unbalanced or unhealthy diet. To ensure you get all the nutrients you need from the food you eat, try to aim for a diet rich in fruit, vegetables, quality protein, healthy fats, and low in processed, fried, and sugary foods.