Whether it comes in the form of chunky sweaters or added muscle, winter is almost universally recognized as bulking season. 

With the colder weather comes not only an opportunity to dive face-first into comforting meals like chili and pot pie, but also to bring lagging muscle groups up to speed or pack on more muscle tissue. So, if you’re itching to make gains, now is the time.

Here, experts outline the essential diet and training changes to make for bulking season. 

Training Tweaks

1. Add More Strength Workouts

To trigger muscle growth (also known as muscle hypertrophy), you need to train muscle groups a minimum of twice—but ideally three times—per week, says Jacob Wilson, Ph.D., C.S.C.S.*D., member of The Vitamin Shoppe Wellness Council and CEO of the Applied Science and Performance Institute.

Of course, you won’t be able to hit every muscle group three times per week (there are only seven days, after all), so Wilson recommends choosing two or three areas to prioritize.

Read More: 6 Common Strength Training Mistakes That Are Messing With Your Gains

Another way to approach it: Get a minimum of 10 and a maximum of 20 sets per body part every week, suggests Stan Efferding, C.S.C.S., IFBB professional bodybuilder and co-author of The Vertical Diet. “I recommend starting with 10 sets and progressing volume over a 10-week block by adding a set each week,” he says.

How you split your muscle groups up into your weekly training sessions will vary depending on which groups you want to prioritize and how many days you have to train, but here’s a sample schedule for someone who has six days to lift:

• Monday: Lower body
• Tuesday: Chest, shoulders, triceps; cardio
• Wednesday: Back, biceps
• Thursday: Lower body
• Friday: Chest, shoulders, triceps
• Saturday: Back, biceps; cardio
• Saturday: Rest

2. Change Up Your Exercises

If you’ve been doing the same exercises for the past six months, now is the time to challenge yourself to incorporate some new ones. The reason: Chances are, your body has gotten accustomed to those exercises, which means it’s probably stopped building muscle as a result, Wilson says. 

To spur new muscle damage (which ultimately equals muscle growth), you need to introduce a different training stimulus. So if you’ve been favoring the barbell bench press, for example, switch to a dumbbell bench press or dips. If you love wide-stance squats, try a narrow-stance variation or move to walking lunges. 

Read More: How To Get Past Your Muscle-Building Plateau

“It might not be a massive change, but it needs to be something different,” Wilson says. “The main thing is to do exercises you haven’t really done for the last year; that’s going to be big for bulking.”

3. Vary Your Rep Ranges

First order of business? Aim to hit every repetition range on your key exercises throughout the week. In other words, do six to eight reps per exercise in one workout, eight to 12 reps the next, and 12 to 15 reps on another. (Yes, that means training each muscle group three times per week.)

Lifting within each rep range will help you tap into the different muscle fiber types, which is the first thing you need for [muscle] growth, according to Wilson.

The low rep range (six to eight) allows you to lift heavier loads and allows you to target your powerful fast-twitch muscle fibers. The middle rep range (eight to 12) means moderate weights, covering both fast- and slow-twitch muscle fibers. And the high rep range (12 to 15) means going light, so you’ll exclusively work endurance-focused slow-twitch muscle fibers.

For each rep range, choose a weight that you can lift with good form for the duration of your sets but is challenging enough that you finish each set feeling like you could only eke out another rep or two, Wilson suggests.

4. Switch to High-Intensity Cardio

Though you may have heard that cardio kills gains, it’s actually an essential component of your bulking phase, Wilson says. In fact, he believes that cutting cardio is one of the most common mistakes many bulkers make.

You see, while cardio won’t help you build muscle, it will help keep fat gain to a minimum and keep you generally fit which is vital for getting through a winter of intense strength-training sessions, Wilson says. If your overall health and fitness decline, you may struggle to make it to the end of high-volume workouts.

He recommends incorporating a couple of high-intensity cardio sessions into your weekly schedule to ensure you’ll be able to keep pace with your strength training. (Try these seven HIIT workouts on for size, if you need some inspiration.)

Nutrition Tweaks

1. Increase Calories

Are you ready to eat? “To gain muscle, it’s important to maintain a calorie surplus,” says Damon McCune, Ph.D., R.D.N., co-author of The Vertical Diet. (That means eating more calories than you utilize.) Your muscles need this extra energy for all the building and repair that takes place as you challenge your muscles day after day. 

In general, he recommends adding 300 to 500 calories to your daily intake, which is enough to help you gain muscle but not so much that you end up with unwanted fat gain.

That said, hard-gainers (people who don’t gain muscle or fat easily) may want to add as many as 750 calories to their diet, Wilson says. 

Instead of consistently eating lots of extra calories, he suggests cycling your calorie intake so that you eat more on intense training days and fewer on cardio or rest days. For example, a hard-gainer might eat an extra 500 calories on a cardio day but go up to 750 on a lower-body strength day.

As you go, keep tabs on how your body responds to those extra calories. “Add calories to the point where you gain a half-pound to a full pound per week,” Wilson says. If you gain more than one pound per week, you’re likely putting on some fat.

2. Focus on Protein

Of the extra calories you add to your diet, the majority should come from high-quality protein sources, Wilson says. After all, protein is the primary macronutrient for repairing damaged muscle and building new tissue. So when you consider which foods to add, look to protein-rich options like fish (avoid types high in mercury, like swordfish and marlin), chicken, dairy, tofu, and protein powder.

Read More: The Best Protein Bars For Every Health Goal

Healthy lifters with no history of kidney complications should aim for at least one gram of protein per pound of body weight every day, McCune says. So, if you weigh 150 pounds, try to get 150 grams of protein into your daily diet. For optimal absorption, space it out amongst three to four meals.