Carb Cycling

The Targeted and Cyclic Ketogenic Diets

You may have heard of ‘carb cycling’, but hearing about a new kind of diet through the fitness community grapevine doesn’t always mean it’s right for you. Gymaholic will show you the different kinds of ketogenic diets and help you decide if one of them might be a good tool to help you reach your goals.

There is the Standard Ketogenic Diet (SKD), and the modified versions of the SKD, which are the Targeted Ketogenic Diet (TKD) and the Cyclic Ketogenic Diet (CKD), which is more commonly known as carb cycling.

Nice burger

Standard Ketogenic Diet (SKD)

There has already been an article published on ketogenic diets, but that article specifically covers the standard ketogenic diet (SKD). This diet is great for fat loss, and low levels of activity are known to increase the benefits of ketosis.

When your body is deprived of carbohydrate (glucose) energy, it enters ketosis, which is when your body relies mainly on fat for energy. When fats are broken down by the liver, you get ketone bodies, hence the name “keto”sis.

Under normal circumstances, we operate in a state of glycolysis, when glucose is broken down and used for energy. Ketosis usually occurs when the body is in a ‘fasted’ state, and low on carbohydrate fuel. It is the body state where you burn the most fat. You can trick your body into the fasted state by following a ‘low’ or ‘very low’ carbohydrate, moderate to high fat and moderate to high protein diet.

For someone eating 2000 calories a day, a ‘low’ carbohydrate diet is usually around 130g of carbs per day, or about 26% of your calories from carbohydrates. A ‘very low’ carbohydrate diet has significantly less, around 50g of carbohydrates per day, or around 10% calories from carbohydrates. The rest of your calories come from protein and fats.

Problems with SKD

If you have medical problems you should consult your doctor first before trying any sort of ketogenic diet. There are also some possible side effects like fatigue, dehydration and vitamin deficiencies that can occur while your body adjusts to ketosis.

Another problem is that unfortunately, the standard ketogenic diet isn’t sustainable for individuals who are moderately to heavily active because the carbohydrate intake is too low.

Weightlifters, bodybuilders and other sport athletes, especially those who do short, powerful bursts of energy, simply can’t function on a ketogenic diet. ‘Short term’ energy is provided by carbohydrate (glucose and glycogen) stores in the body, and since there is a limited amount that the body stores, when that runs out fat stores must be used.

Fat however, cannot be metabolized for energy as fast as carbohydrates (they are a ‘long term’ endurance energy source), so that high powered activity can’t be continued and that person will fatigue much faster. There is also a higher chance of losing lean muscle mass.

So what is the solution for those athletes that want to keep fat at bay, but maintain their lean muscle mass and energy while exercising? The targeted ketogenic diet (TKD) and the cyclic ketogenic diet (CKD), also known commonly as ‘carb cycling’.

Summary (SKD)

Targeted Ketogenic Diet (TKD)

In the targeted ketogenic diet, carbohydrates are consumed immediately around exercise to refill those glycogen stores for sustaining exercise and preventing lean muscle mass loss, without affecting the fat burning effects of ketosis. However, this diet will not increase your muscle mass or strength.

This is a stepping stone between the SKD and CKD. You are leaving ketosis for a short period of time, but not for over a day (like in carb cycling). This diet can handle fairly intense exercise, so it can be used for people who exercise frequently at beginner and intermediate levels.

A little experimentation is required to decide how much carbohydrates you should consume and how long before a workout you should consume them. Everyone is different, but somewhere between 25-50g of carbohydrates, around 30 mins before your workout is a good place to start. Post workout carbs should not be taken unless you feel you need them because you want the body to return to ketosis as quickly as possible.

Simple, sugary carbs are usually the carbohydrates of choice because the glucose (sugar) is digested and released quickly into the blood. The spike of the hormone insulin that follows causes that glucose to be taken up and stored in the muscle.

Problems with TKD

TKD has similar problems as SKD. It is still a ketogenic diet so you would likely experience the same side effects of your body adjusting to it. With the TKD it may take longer for your body to adjust to ketosis since you are going in and out of it.

Promoting consumption of sugary carbs can hurt those trying to develop a healthy relationship with food. Alongside that, if you attempt TKD with very minimal exercising as an excuse to consume higher carbs, you may not see the results you want.

Summary (TKD)

  • Low carbohydrate diets promote ketosis and fat burning. It will not increase muscle mass or strength.

  • Consuming extra carbs around your workout keeps fatigue at bay and reserves muscle mass.

  • Can support beginner to intermediate activity/exercise levels.

  • Adjusting to ketosis can cause fatigue, dehydration and vitamin deficiencies. Constantly readjusting can prolong these effects.

Omelette

Cyclic Ketogenic Diet (CKD)

The cyclic ketogenic diet, also known as “carb cycling” is the most extreme modification of the SKD. Instead of just consuming carbohydrates before or around your exercise times you cycle through “high carb” (around 2-3g/lb in males), “low carb” (around 0.5-1.5g/lb in males) and “no carb” days fairly equally through the week.

“No carb” days are technically just very low carbohydrate days, because it is nearly impossible to achieve no carbs. This is why vegetables are consumed on all days, and should not count towards your carbohydrate total. A lot of water should also be consumed.

The purpose of this diet is the same as the TKD: refill muscle glucose/glycogen to sustain performance and prevent the loss of lean muscle mass. However, the carbohydrates are increased more, for even longer for those at a frequent, advanced exercise level.

High carb days are for the most heavy and challenging workout days, and then you rotate through low and ‘no’ carb days following. If you work out in the morning, it’s recommended to have a low carb day before a high carb day and/or ensure you consume enough carbs before your workout in order to get the benefits.

Consuming carbs after your workout can be a bit more helpful in the CKD because you want to refill the glycogen stores to prepare for the next workout, which can take over 24 hours. The order of the carb cycle can be changed to jump start fat loss if you reach a plateau, or increase your energy if you feel that your glycogen stores may be lacking before a workout in a current schedule.

7 Day Examples:

Low | High | No | High | Low | High | No… For scattered heavy workouts.

No | Low | No | Low | High | Low | High… For a heavier weekend recovery.

Problems with CKD

The same problems can occur as with both the SKD and TKD, with the side effects of adjusting to ketosis. The extremes of going between carb heavy and ketosis could potentially make these side effects worse or better, it depends on the individual and the cycle they choose to follow. This diet should most certainly not be undertaken by anyone who had medical problems without speaking to a doctor first.

This is a bad diet choice for anyone who is not frequently and intensely active. If there is no exercise to drain the glycogen/glucose stores so they can be refilled, if there is not enough fat being burned, there is potential to gain weight. This diet can keep you lean, and protect that lean muscle mass from being catabolized, but it will not increase muscle mass and strength gains.

The constant changes between high carbs and very low carbs can encourage a binging and purging mentality, but can also cause other problems as well. There is little information on the problems caused by jumping into ketosis and then binging on carbs and spiking insulin, but if you have medical problems it could potentially put you in danger.

CKD Summary

  • Low carbohydrate diets promote ketosis and fat burning. It will not increase muscle mass or strength.

  • Having full days of increased carbohydrates can better support intermediate and advanced activity levels, keeps fatigue at bay and preserves muscle mass.

  • For beginners to intermediates it could cause weight gain and may promote binging and purging.

  • Adjusting to a combination of ketosis and high carb consumption can cause undetermined side effects. If you have medical problems it could potentially put you in danger.

Conclusion

Ketogenic diets are not for everyone, but there are a few variations on the standard ketogenic diet that may be a better fit to your lifestyle. They can be easier to execute because you are simply watching your macros, but things can get more complicated if you are more active.

Work hard and stay safe!

References:
Hartnett, Thomas. "Carb Cycling: Is It All It's Cracked Up To Be?.".
Seidell, J. C., et al. "The Science Behind The “Low Carb Flu”, and How To Regain Your Metabolic Flexibility." Int J Obes Relat Metab Disord 16.9 (1992): 667-74.
McDonald, Lyle. "The ketogenic diet." Macdonald, Austin, TX (1998).
Date, Join. "An In-Depth Look Into Carbing Up On The Cyclical Ketogenic Diet With Lyle Mcdonald."

Responses
Write a response...