As the warmer months approach and your winter layers come off, it's only natural to shift from a mass-building workout program in favor of a fat-trimming protocol.

The only problem? That transition usually leaves you feeling spent. As you throttle back on carbs and start doing more metabolically demanding workouts, your usual intensity might start to fade. Some guys feel lucky if they can get through their daily cardio regimen. Having a lean body is great and all, but if you feel like crap for the sake of abs, where's the fun in that?

That sluggish feeling is totally normal—expected, even. Loads of guys struggle with low energy levels when they make the switch from bulking to cutting.

To help explain why, we hit up Louie Antuna, C.P.T., a fitness and nutrition specialist who helps clients transform their bodies via his LA Method, and Jennifer Ventriglia, an MMA fighter and trainer based in New York. Use their tips to make the "cut" process easier on your mind and body.

Why you feel drained when you start a spring/summer weight loss program

For starters, if you're cutting certain foods or reducing certain macros in your diet, your body's gonna start feeling the effects. "Cutting calories is mainly done by eliminating sugars and carbs," your body's main source of energy, Ventriglia says. "Because bulking season highlights higher carbohydrate intake, your body requires adequate time to readjust to the nutritional shift and the drop in sugars," she explains.

Likewise, "if you cut your calories too low, you’ll feel depleted because that quick energy source is no longer there," Antuna says. Anything too abrupt and/or too extreme taxes your body. A better approach is to throttle back on carbs to lose weight over time, he says.

Furthermore, most guys don't do cardio during bulking season, which often means "your body isn't conditioned to perform for longer periods of time at an accelerated heart rate," Ventriglia explains. In that condition, starting a high-cardio program and a lower-calorie diet will make any guy dog-tired, Antuna says.

Boost your energy during a weight-loss program

Don't get us wrong: "Carb-cutting is the most efficient way to lose weight, if done correctly," Antuna says. Ventriglia adds, "When you cut back carbs, your fuel source has to come from higher amounts of lean protein and nutritionally dense, leafy veggies, like spinach."  Introduce foods that are lower in calories but give you higher amounts of brain- and muscle-stimulating energy, like eggs, edamame, and quinoa. (We like these 10 energy-boosting eats and these 10 fatigue-fighting foods.)

"Another important aspect of your daily macronutrients is incorporating healthy fats—such as salmon, avocado, and nuts—into your diet," Ventriglia says. "They'll help to keep you fuller and more nutritionally balanced." Try eating more fiber-dense fruits, veggies, and grains like raspberries, broccoli, black beans, and these 15 foods that keep you fuller longer.

For quick-hit energy, eat a piece of fruit. Just know that nature's candy can pack a lot of sugar and should be consumed in moderation if you're trying to cut body fat, Ventriglia says. Tomatoes, blackberries, and these low-sugar fruits will help you cut weight.

Lastly, ramp up your protein intake. "A good rule of thumb to follow is to consume at least 1–1.3g of protein per pound of body weight," Ventriglia adds. If you weigh 175 lbs, your diet should consist of 227.5g of protein per day (1.3g x 175 lbs). Hone a leaner physique and ward off hunger with these top 20 meat proteins

Taper your workouts so your shred is less extreme

"You need to closely monitor your workout regimen when you execute a caloric deficit," Ventriglia says. Because your body doesn't have its usual fuel sources, you run a higher risk of overtraining and injury. "Pay close attention to not only how your body is responding to your diet change, but to how it's performing during your workouts as well," she says. After all, your efforts are wasted if you're too tired to even make it through the workouts.

Also: Ease into the cardio. "In the beginning, if you can talk while doing cardio, that's a good start," Antuna says. That intensity may not feel like much, but it's important because it means you can do a solid resistance-training session without feeling maxed out on cardio. "Monitoring your heart rate for fat-burning efficiency is a great way to help find a healthy zone for you," Antuna says. Use a tracker capable of telling you what that range is. As for the type of cardio, Antuna recommends the stair-climber. "It's a great option, because you can control you heart rate with minimal impact on your joints," he says. 

Change up your typical cardio routine

"Incorporating several types of training strategies—HIIT cardio workouts, circuit training, or muscle-endurance exercises—together helps to combat fatigue," Ventriglia says. Not only do your muscles get a new, challenging workout, but your brain also enjoys a new challenge, too.

Recognize how work and play factor into the equation, too. Train in the morning if you know you have a full day of meetings that'll run late or you're going out with friends.

Also, be willing to make adjustments to your diet and your training—and be strategic about meal timing. If it's helpful for you to do fasted cardio in the morning, then make breakfast or lunch your biggest meal. If you'd rather work out in the evening (and have some food in the tank), then time it so you eat a banana with almond butter, oats, or any of these great pre-workout foods about an hour or two beforehand, which will help prevent a foggy brain, slow reflexes, or low overall energy. Then have a protein shake post-workout to kick-start the recovery process. 

Lifestyle tweaks that can keep energy levels high during a shred

  1. "Ensure you're able to get a solid six to eight hours of sleep a night," Ventriglia says. Can't fall or stay asleep? Here are 15 things you can do during the day to help you fall asleep faster at night.
  2. Get the proper fuel for every workout and leave adequate time for digestion, she adds. Learn how to prevent common stomach issues mid-workout
  3. "Make recovery as important as your training," Ventriglia stresses. These six ways to recover from your workout can help. 
  4. Aim to drink at least a gallon of water a day, Ventriglia says. "Upping water intake will have a positive effect on your body as you begin to lean out," she adds.  
  5. "Find alternative ways to contribute to your health because you can only spend so much time in the gym," Antuna adds. It'll help you reach your goals sooner and more sustainable. "Enjoy the route you create. Try to hit 10,000 steps a day. Play golf or bike on the weekend." Make this process as enjoyable as possible.