If you've been sweating it out on a regular basis and the scale has barely budged-or worse, it spiked-you can likely blame an imbalance of two key weight-loss players: calories in (how much you eat) and calories burned (how much you worked off). What looks simple on paper gets tricky in practice, because a crazy-hard sweat session not only torches calories and revs your metabolism but can also up your hunger quotient.

Luckily, a few quick tweaks are all you need to make sure your workouts are helping-not hurting-your pound-shedding efforts.

Sweat by Numbers

Sorry to break it to you, but your last ubertough workout probably didn't torch nearly as many calories as you thought it did. "People grossly overestimate how many calories they burn during exercise, especially when they think its high intensity," says Eric Doucet, Ph.D., a human kinetics professor at the University of Ottawa. It doesn't help when your boot-camp instructor says each class blasts 1,000 calories (a total exaggeration) or you check the counters on cardio machines (ellipticals have been reported to overestimate expenditure by 42 percent).

"Estimating calorie output can be an inexact science," says Georgie Fear, a registered dietitian for Precision Nutrition. That's because it involves factors like age, weight, body temperature, metabolic rate, and hormonal changes (to name a few) that are complicated, difficult to track, and ever fluctuating. Many cardio machines, for example, factor in just age and weight-and are calibrated for men. What's more, at higher intensities, or as the machines get older, the readouts may become less accurate. To help combat this, increase your goal calorie burn by 30 percent. So if you go to the gym with the intention of burning 300 calories, aim for 390 calories instead.

Instead of focusing on numbers, monitor your intensity by focusing on your perceived effort-how difficult the workout feels. In the weight room, the last few reps of every set should be tough to finish (if they're not, bump up the weight or number of reps). During cardio workouts, add short bursts of speed to shock your body and spike your burn. After warming up, speed up to your near all-out max effort (it should feel unsustainable) for 30 seconds, then slow to a conversational pace for three minutes. Repeat six times

Calorie Conundrum

If you've been logging tons of miles or you're a gym regular and you still aren't seeing changes, it's time to take a closer look at your diet. Moderately active women typically need a ballpark of 1,800 to 2,200 calories a day to maintain their weight, says Fear. To drop pounds, you'll need to shave anywhere from 250 to 500 calories a day from that total. Seems simple, right? Not quite. After exercise, adrenaline and endorphins are flowing, and in this elated state, women often feel they deserve a post-workout treat or can splurge on a high-calorie lunch.

In a study published in The Journal of Sports Medicine and Physical Fitness, found that college students consumed up to three times more calories than they burned during an earlier workout. Researchers think people may be less mindful of what they're putting into their mouths. Many women also reward their gym efforts by being less active throughout the rest of the day (by, say, not taking the stairs or spending more downtime on the couch).

Even if you can resist the reward mentality, how you feel after working out-exhausted, drained, possibly ravenous-can reinforce the idea that you burned a ton of calories and your body needs more fuel. While serious athletes need pre-and post-workout calories to offset their demanding training, the average woman is fine. Translation: Put down the sports drink, gel, or jelly beans. You don't need them after an hour at the gym.

If necessary, beat exercise-induced hunger pangs with a 200-calorie snack (a mix of carbs and protein, like half a turkey sandwich) within 30 minutes of exercising. Just remember to figure the calories into your daily count-not in addition to it.

The Perfect Balance

Once you sync up your diet and workout, be patient-successful pound shedding takes time. "Fat loss and weight loss don't always go hand in hand," says Ben Hurley, Ph.D., a professor of exercise physiology at the University of Maryland. While endless cardio and a restrictive diet might lead to the fastest drops on the scale, you're often losing fat, water weight, and muscle mass. The combo of cardio, weight training, and healthy eating might mean slower losses, but you'll likely ditch flab while building good habits that you can maintain over time.