June 25, 2019

How to Exercise When You’re in Keto

We all know at this point that eating in Keto does help tremendously with weight-loss. Just look at the Keto sub-reddit and it is very clear how effective the keto lifestyle is! What we also know is that exercise is good for the heart and mind but what happens when the two come together. Is it possible to exercise and follow the ketogenic diet?

I exercise most days, for my mind more so than my body. Back in February whilst in keto I attempted to do a HIIT workout. Now, it was only 20 minutes total of 40 seconds on and 20 seconds rest but I swear I nearly died!  What I didn’t know is that withholding carbs can cause some changes and effect your exercise performance especially HIIT. The bloody one time I don’t Google something 😆But thankfully, exercise can fit into your Ketosis lifestyle once you know what to do and when to do it! So if this sounds like something of interest to you, then read on for some tips on how to exercise when you’re in keto 😀

How to Exercise When You're in Keto

How Keto Impacts Exercise Performance

The first thing to understand is how keto changes the way our body works during exercise.

For those eating a normal non-keto diet the body would feed on glucose (sugar) during a HIIT workout (High Intensity Interval Training such as 40 seconds on 20 seconds off). This means that the person has the fuel for lots of short bursts of high intensity!

On the other hand, for those who follow keto, your body has zero glucose stores due to the fact that you aren’t eating carbohydrates. Since our muscles relies on glucose as fuel during these workouts it is obvious that your performance will be effected. I felt as though I was being hit by a bus with each burpee 😮. Put simply, your body is lacking in the sugar that it needs to fuel activities that require a high-intensity effort for 10 seconds to 2 minutes. This means that ketogenic diet CAN limit your performance during high-intensity activities like:

✔ Crossfit

✔ HIIT workouts

✔ Any workout you’ve never done before

Basically, anything that requires you to exert short bursts of energy don’t belong in your exercise regimen if you’re following keto. You also shouldn’t start a brand-new workout routine when you’re on this diet. Adjusting to exercise on keto is hard enough on your body when it’s already used to exercise.

Cardio and Keto 

The good news for the cardio bunnies out there is that cardio is the perfect exercise for keto. The beauty of cardio workouts is that you don’t have to exercise at high-intensities that require your body to burn sugar and glycogen to get results. All you need to do is get your heart rate up and keep it up. The intensity that you need to maintain to get the most benefits is defined as “moderate intensity” by the CDC. For moderate-intensity physical activity, a person’s target heart rate should be 50 to 70% of his or her maximum heart rate. So if your max heart rate is 180 bpm, then moderate intensity would be working out in the 90-125 bpm zone.  With cardio you don’t need to change your macros or what you’re eating for additional energy!

Weightlifting and Keto

Strength, power, and muscle mass can all be increased while you are on the ketogenic diet. Your body doesn’t need carbohydrates for building muscle but rather for repairing muscle and so weight-lifting isn’t negatively impacted by keto! Lifting weights daily is an excellent way to work your body and challenge yourself. In comparison to regular bodybuilding, for keto the optimal rep range for building muscle is 5×5 or 5 sets of 5 reps as opposed to traditional reps of 4×15 😳

Sample Workout
Exercise Equipment Muscle Sets Reps
Barbell Squats Barbell Legs 5 5
Barbell Bench Press Barbell Chest 5 5
Bent Over Row Barbell Back 5 5
Barbell Shrugs Barbell Traps 3 8
Standing Overhead Tricep Extension Barbell Triceps 3 8
Standing Barbell Bicep Curls Barbell Biceps 3 8

Remember to Eat Enough Protein

If you’re weight-lifting then you need to ensure you are eating enough protein and this is the same for the keto diet. Your body cannot run on fumes and so you need to ensure you are fuelling it correctly for your keto workouts! The typical keto diet is 75% Fat, 20% Protein and 5% carbs. You need to be eating around 1g of protein per pound of body weight to help you grow muscle, repair and have sufficient energy.

So for example, a non-exercising 140 pounds woman who follows keto and wants to lose 14 pounds would be eating 59g of protein per day along with her fat and carbs. If this woman starts exercising and wants to gain muscle and improve her energy then she would need to be consuming around 140g of protein per day!

Do not be alarmed by the higher protein intake as your body will use the excess protein to provide your muscles with the glucose that they need by using a process called gluconeogenesis. Gluconeogenesis is where excess protein is converted to glucose and used for immediate energy such as working out.


To Sum up

Your health and well being are the most important thing regardless of your want to eat right and exercise. Listening to your body is the most important piece of advice to take away from this. If you feel weak, dizzy or tired then give yourself a rest day. Be proud of the fact that you’re up off the couch and not at home binging on Netflix 😉Also, some other key points below.

 Moderate cardio workouts such as cycling, jogging, elliptical machine, or swimming are perfect for keto.

✔ Strength training exercises such as weight lifting (fewer reps with heavier weights) I usually do 5 sets of 5 reps are great.


Thanks for reading

Natasha 🤗