Cristiano Ronaldo returned to training with Real Madrid just one month after suffering a sprained ligament in his left knee.

Cristiano, who broke up with Russian supermodel Irina Shayk in 2015, is happy living the single life while being a devoted dad to son Cristiano Jr.

In smoking-hot new ad photos for his CR7 Underwear line, Cristiano spotlighted his six-pack abs and rippling body.

Ronaldo’s fitness secrets are a high-protein diet and exercise sessions that include cardio workouts, weight training and soccer, Celebrity Health Fitness reported.

The 6-foot-1 Ronaldo, who weighs 176 pounds, said his health and fitness secrets include the following:

1.   Learn to train your mind as well as your body. Mental strength is just as important as physical strength and will help you achieve your goals.

2.   Proper sleep is really important for getting the most out of training. I go to bed early and get up early, especially before matches. Sleep helps muscles recover which is really important.

3.   Mix it up. I recommend a combination of cardio (running and rowing) and weight training to ensure that workouts target all areas of the body and increase both strength and stamina. It also helps to keep it interesting.

4.   High intensity is important to get your blood pumping and to increase stamina. We do a lot of sprinting drills in training and they can be incorporated into your workout whether you are in the gym or outdoors. Try and add it to every workout you do.

5.   Cardio sessions are also key for building up endurance and stamina, and to stay trim. Try to do periods of around 30 minutes, increasing the number of sessions as you get stronger.

Enjoy??

A photo posted by Cristiano Ronaldo (@cristiano) on

6.  A good workout must be combined with a good diet. I eat a high-protein diet, with lots of whole grain carbs, fruit and vegetables and avoid sugary foods.

7.  Make sure you stay hydrated. Drinking water is so important. I also avoid alcohol.

8. Fit in exercise wherever you can. You can do an abs workout in your bedroom when you wake up in the morning or before you go to bed. If you get into a routine then it makes it easier as it will become a habit.

9. Relax. Training and physical sessions are most important, but living a relaxed lifestyle helps you to be the best you can be, physically and mentally. I spend my free time with family and friends, which keeps me relaxed and in a positive mind-set.

Cristiano, who has been playing soccer since age 3, is a study in extreme physical fitness.

During his six years at Manchester United, Ronaldo won three Premier League titles, the UEFA Champions League, an FA Cup and the FIFA World Club Cup, as well as the FIFA Player of the Year title.

In 2009, Cristiano made international headlines when United agreed to sell him to Real Madrid for a stunning $131 million transfer fee, making him the most expensive player in European football history.

Ronaldo’s 2016 salary at Real Madrid was 17 million euros (or $19 million), and his net worth has been estimated at more than $400 million.

Despite his success, Cristiano, 31, still has a burning hunger to improve and has no intention of resting on his laurels. “I want to get better and better,” he said. “My ambition is huge.”

CR7’s legendary self-discipline and work ethic is detailed in the book Cristiano Ronaldo: The Rise of a Winner.