Intermittent fasting (IF) is a huge buzzword in health and fitness right now, and for good reason! When paired with the right exercise program, it can increase fat loss, increase energy and help you build muscle. But how does it work and what is the best way to define it alongside exercise? Let’s break it down.
What Is Intermittent Fasting (IF)?
Intermittent fasting is an eating pattern that cycles between periods of fasting and eating. Unlike traditional diets that focus on typically what you eat, IF focuses on when you eat. Some of the common methods include:
- 16/8 Method – Fast for 16 hours, eat within 8 hours (e.g. 12 PM–8 PM).
- 5:2 Method – Eat normally for 5 days, eat very few calories (~500-600 calories) for 2 non-consecutive days.
- Eat-Stop-Eat – 24hr fasting 1-2 times a week.
How IF Improves Fitness Outcomes
1. Increases Fat Loss
- Fasting reduces insulin levels which forces the body to burn stored fat for energy.
- Increases human growth hormone (HGH) which helps with fat loss, while maintaining muscle.
2. Enhanced Work-Out Performance
- Training fasted (such as morning fasted cardio), might enhance fat oxidation.
- Some claim that athletes have greater clarity and endurance during fasted training.
3. Promotes Muscle Growth (If Done Properly)
- You need to think about protein timing – to preserve muscle mass you should be getting enough protein during your eating period.
- Combine intermittent fasting and weight training to maintain (or gain) muscle while losing fat.
Best Workouts with Intermittent Fasting
Certain activities are better suited for fasting than others. Here’s how you can make sure you workout effectively:
Best During Fasting:
- Low-intensity cardio (i.e. walking, cycling, yoga)
- Bodyweight workouts (i.e. push-ups, squats, lunges)
- HIIT (short duration – moderate intensity)
Best After Breaking your Fast:
- Heavy lifting (i.e. weightlifting, powerlifting)
- High volume weight training (i.e. long runs, intense Crossfit)
Sample of Fasting + Fitness
The following is a helpful sample plan which combines intermittent fasting and workouts:
- 6:30 AM – Fasted workout (light jog or bodyweight exercises)
- 8:00 AM – Black coffee/green tea (This keeps you fasted but gives you energy)
- 12:00 PM – Break fast with protein + healthy fats (eggs, avocado, lean meat)
- 6:00 PM – Strength Training ( post-meal for perfect performance)
- 8:00 PM – Last meal (high-protein, complex carbohydrates for recovery)
Common Mistakes to Avoid
- Do not eat enough protein → You risk losing muscle mass.
- Overdoing your fasted cardio → You can burn out and fatigue.
- Dehydration → Hydrate yourself (with plenty of water and electrolytes).
- Ignoring your recovery → Fasting + hard training requires you to recover.
Who Should (and Shouldn’t) Use IF + Fitness?
Great for:
- Those wanting to lose fat while preserving muscle.
- People with busy schedules that prefer fewer, larger meals.
- Endurance athletes looking to experiment with metabolic flexibility.
Not great for:
- Underweight individuals or have a history of eating disorders.
- Pregnant/nursing women or individuals with medical conditions (speak to a doctor first).
Final Conclusion
Intermittent fasting can be a huge benefit for fat loss and fitness—if done right. The right type of workout, good amounts of protein, and listening to your own body!
