If you've been sticking to your fitness routine and you haven't achieved the waist-trimming outcome you'd wished for, don't stress it; we've got some science-backed ways to boost the fat-burning ability and make every sweat droplet count.

Below, you'll find professional advice on how to improve your performance and enhance your pre-and post-workout weight loss.

Have a jolt of caffeine

A study has shown that drinking caffeine before exercise will increase athletic performance. Plus, a report released in Sports Medicine shows that a natural energy supply can help you exercise longer in workouts ranging from 60 seconds to even two hours. Only note to miss the sugar and creamer you have applied to your coffee to avoid packing the pounds on your body.

Try fasting

If you're trying to get lean, it could be your best bet to work out before you sit down on sunny-side-up eggs and toast. Research in the British Journal of Nutrition showed that doing cardio on empty stomach results in slightly greater fat oxidation or fat reduction than doing exercise after you have eaten. Before breakfast, consider hitting the elliptical or Stairmaster and take a quick snack with you to the gym to keep your blood sugar in check.

Go nuts

But what if we told you that replacing your sugary pre-workout snack for your favorite nut could help make your workout more efficient? According to a report in the Journal of the International Society of Sports Nutrition, popping about 2.6 ounces of whole almonds has enhanced the aerobic capacity of cyclists and boosted the usage of oxygen better than sweets. Researchers believe that almond nutrients such as arginine and quercetin can contribute to these fat-burning effects.

Whey in

Make sure you follow up your leg day with a muscle-replenishing protein shake. According to research published in Sports Medicine, supplementing strength exercise with whey protein helps the body develop a lean muscle. And the more mitochondrial muscle mass you're packing, the more fat you're going to burn, even at rest. Moreover, the analysis found that the whey and resistance exercise combo both enhanced upper and lower body efficiency. Will you want to kick the fat-loss with a notch? Researchers have found that these magnificent effects have been improved when whey is paired with creatine.

Try HIIT

High-intensity interval training (or HIIT) increases metabolism, eliminates calories, and creates muscle. High-intensity interval training is where you workout at or above your full capacity for a limited amount of time, and then take a quick break and do it again. HIIT can usually be performed at a period of 2:1, i.e., if you completed a one-minute routine, rest for 30 seconds, and then repeat. This can be a perfect way to flatten your stomach when you don't have that much time to work out.