Which Cardio Intensity is Best for Fat Loss?

While there are many different schools of thought on what Frequency, Intensity, Time and Type of Cardio is the ultimate best for fat burning, Fit for Faith Christian Fitness Ministries has broken down each and has outlined each type of Cardio Intensity is Best for Fat Loss. We have also listed some benefits and risks that are inherent with each type of cardio intensity and how it will apply to your fat loss.

Fasted cardio in the morning

earlymorningcardioOne of the most controversial fat loss techniques is performing cardio first thing in the morning on an empty stomach. This method is widely embraced by bodybuilders and recommended by many Personal Trainers and nutritionists. Other experts claim that the risk of muscle loss is too high and they argue whether workout timing makes any difference in the overall scheme of 24 hour energy expenditure. With low blood sugar and low glycogen levels on awakening, it appears that the body is in a perfect state to burn fat preferentially, but combined with high a.m. cortisol levels, it may also be a perfect state to burn muscle. Therefore, the benefit is high, but so is the risk. Body composition must be carefully monitored when using this technique.

RISK: 3 (high)
BENEFIT: 3 (high)

Cardio in the morning after protein consumption

One of the biggest concerns brought up by opponents of fasted morning cardio is the potential for losing lean body mass. One way to help combat the possible loss of lean body mass is to eat a small protein-only meal or to consume a protein drink (no carbs) immediately upon awakening, then perform the cardio shortly thereafter. This decreases the risk by suppressing cortisol and preventing muscle breakdown, while maintaining the high benefit by keeping your blood sugar and insulin levels low.

RISK: 2 (moderate)
BENEFIT: 3 (high)

Cardio at night

nighttimeMany bodybuilders and Weight Loss seekers perform cardio late at night and then do not eat afterward in an attempt to increase fat loss. There are benefits to this method, but they are moderate at best, and the risks are high. Late night training may also keep you awake, disrupting your sleep cycle and recovery. Once you do fall asleep, your metabolic rate decreases rapidly, so you don’t reap the full value of the post workout metabolic increase that is achieved with exercise earlier in the day. Risk of muscle loss is high, so body composition must be monitored very closely.

RISK: 3 (high)
BENEFIT: 2 (moderate)

Short duration, high intensity interval training

HIIT2One of the most popular trends in fitness today is high intensity interval training (HIIT). These workouts consist of short periods of high intensity work intervals followed by short periods of lower intensity recovery intervals. Generally, the intervals are 30 to 120 seconds in length and the total duration is in the 15-25 minute range. Research has shown that H.I.I.T Training causes a larger increase in post-exercise energy expenditure than moderate intensity, steady-state exercise, which keeps you burning calories at an elevated rate for an extended period even after the workout is over. There are risks, especially to the beginner, the deconditioned or the person unaware of his or her health status. However, because intensity is relative to each individual, risk is moderate and easily managed, while the benefits are high. For someone who is already highly fit, the risks are lower.

RISK 2 (moderate)
BENEFIT 3 (high)

Moderate duration, moderate to moderately-high intensity cardio
When cardio is performed for a moderate duration (approx 30 to 45 minutes per session) with the intensity held at the upper end of the “target heart zone,” (moderate to moderately-high), large amounts of body fat can be burned during the session. There is also a substantial post exercise elevation in metabolic rate, which, although not as high as that experienced from HIIT, also has a measurable impact on fat loss after the workout.

RISK: 2 (moderate)
BENEFIT: 3 (high)

Long duration, low intensity cardio
long duration low intensityLong duration cardio (60 minutes per day or more) does carry the benefit of more calories burned from fat and a moderately high cumulative calorie burn. However, intensity and duration are inversely related, therefore long duration cardio, by nature, is low in intensity. Low intensity cardio, while having the benefit of burning more fat relative to carbs, does not burn as many total calories per unit of time, nor does it have much impact on post exercise energy expenditure. This makes long duration, low intensity cardio (such as walking) most appropriate as a fat loss technique for beginners who can’t achieve higher intensities yet. Furthermore, this method is not time efficient. A long walk can be a very good (if not ideal) fat loss method for someone who is unfit, older, overweight, or has orthopedic problems. It also provides great health and even mental benefits. But there is little point in doing an hour or more per session when you can achieve equal if not greater Calorie Burn and post exercise metabolic increase by doing briefer sessions with higher intensity.

RISK: 1 (low)
BENEFIT: 2 (moderate)

High frequency cardio (5-7 days per week)

Daily cardio performed at a sufficient intensity is considered by many to be a no-brainer fat loss technique for two reasons: First, total caloric expenditure is increased over the course of the week. Since fat loss is a function of calories burned versus calories consumed, increasing cardio activity from three days per week to six days per week, will in theory, double the rate of fat loss in that period. Second, frequent cardio helps maintain metabolic momentum and keeps the metabolism “spinning” by avoiding long periods of inactivity, resulting in metabolic slowdown. These two factors make the benefit of this technique high. There is moderate risk, however, of overtraining or muscle loss. Risk of aerobic adaptation also increases if the high frequency is maintained over a prolonged period of time. Risks increase relative to the duration of each session and the number of weeks the high volume is maintained. Brief daily sessions have an even more favorable risk to benefit ratio.

RISK: 2 (moderate)
BENEFIT: 3 (high)


I know that finding the Cardio Intensity that is Best for Fat loss is an ever-present question on everyone’s mind.  The important thing to keep in mind is that each and every one of these durations and intensities have something to offer the person in the way of cardio for fat loss. Ultimately, you need to make sure you mix up and vary your training sessions so that you are not doing the same 45 minutes at a snail’s pace on the treadmill at the same incline and speed each time you perform your cardio.  If you have any questions on how you can vary your training, please do not hesitate contacting us here at Fit for Faith Ministries – We Are Building a Stronger Bod


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