As we all know, one of the main reasons behind doing cardio is its ability to efficiently increase energy expenditure, which burns calories, resulting in fat loss. But cardio doesn’t have to be boring or be used as a primary tool for weight loss. It can also be fun, sustainable, and multi-functional training.
Optimization is about tweaking different parameters of one’s training, so we can get to the targeted results faster. If our goal is to lose weight, aside from the nutritional changes we ought to make, here are some quick ways to easily optimize our cardio, to burn more fat.
From cardio timing, frequency and intensity, up to pre or post-cardio supplements, cardio in a fasted state (on an empty stomach), and aerobic training structure, we give out many tips and hacks. Before jumping into your cardio session, you should be aware that no cardio hacks, tricks, tools, and supplements will cause weight loss if you’re not in a caloric deficit.
The Top 6 Cardio Hacks For Fat-Loss
Like aerobic exercise, cardio is pretty efficient in burning calories. Generally, we should aim at a rhythmic activity that we can repetitively do for a certain duration of time. Preferably, performing an easy session, coordination-wise, may prove more efficient in the long run.
The easiest types of cardio to perform (coordination-wise) are running, swimming, cycling, elliptical, stair climbing, and hiking. However, with the proper control of movement, body awareness, and agility, exercise such as skipping rope, kick-boxing, Nordic skiing, and skating can make a hell of a cardio workout too.
It is worth noting that cardio comes with many other physiological benefits on the body, and calorie burning isn’t everything there is to cardio.
1. Do Cardio After Strength Training
If you aren’t a “cardio-only” type of person, you’re probably combining both strength training and cardio workout. But the order in which you do these two, seems to matter.
If your main goal is to build strength, especially for the lower body, weights should come first. The reason behind this is simple. Endurance type of cardio will reduce neuromuscular activation and waste the fuel of your muscles, leaving your muscles dry for weight training. HIIT or a more intense type of cardio will burn up many of the specific fuels for weight training, like creatine phosphate and glycogen, leaving your muscles weaker.
It turns out that submaximal activity (cardio) that follows after resistance training can increase fat oxidation, which stimulates the “fat-burning” effect more effectively, according to a 2007 study, published in Medicine & Science in Sports & Exercise. (1)
However, in the case of long endurance training, purposefully made to improve aerobic performance, weight training prior to endurance, can be detrimental. In a study published in the Journal of Human Kinetics, 13 young males who did hypertrophy and plyometric strength protocols, prior to their endurance work had reduced their maximal voluntary contraction, rate of force development, and shortened their time-to-exhaustion. (2)
Another great reason to put your cardio second is its ability to speed up recovery. Although it might seem counterintuitive, a short 10-30 min cardio session after strength training may be effective in reducing lactate in the muscle. The mechanism behind this is pretty simple, improved circulation allows more waste products to move, and more oxygenated and nutrient-rich blood to travel to the cells.
Submaximal cardio after strength training enhances weight loss and fat loss, reduces lactate, improves regeneration, and has a better “fat-burning” effect compared to cardio prior to strength training.
2. Morning Cardio Beats Evening Cardio
Our bodies biologically function in rhythms. One of the main is diurnal rhythm, synchronizing the day and night cycle. This is quite important, as our body temperature, hormone levels, and many other physiological factors change throughout the day.
So when are our bodies at the peak performance level, best suitable for a workout? A study published in the Journal of Strength and Conditioning Research shows that for aerobic exercise, it doesn’t matter that much. When training for mobility, flexibility, strength, or power, our bodies can profit more from working out in the afternoon. (3) Partially, the reason for this lies in more optimal physiology, hormone levels, higher body temperature, and neural activation. These factors help us to perceive the same level of effort, as it is easier.
Although this is very individual and everyone should adapt it to their lifestyle, morning cardio is far more likely to happen, and be sustained. The reason for this lies in our discipline, motivation, and productivity values, all of which are greater in the morning.
While many still believe that evening cardio can disturb sleep, because it increases neural activation, increases muscle tension, and stimulates the sympathetic nervous system, research contradicts this. An article published in Sleep Medicine shows that evening cardio didn’t disturb sleep. However, it’s fair to say the measures were subjective and self-reported, and that it was shown that vigorous activities in the morning were beneficial in terms of good sleep quality and waking up refreshed. (4)
So by far, morning cardio wins. Another research also states that morning workouts are better for overall weight loss. In obese and overweight individuals who were physically inactive, those that had early workouts had significantly greater weight loss results. This again shows that if your main goal is weight loss, morning cardio might be the king. (5)
Partially due to higher productivity and motivation, morning cardio is more sustainable and might be better for weight loss, without disturbing sleep.
3. HIIT Beats Long Endurance Cardio
When it comes to fat loss, the most important question is whether long endurance activities are better than high-intensity interval training. We all know that the total calorie expenditure during a workout, will be in favor of the longer sustained endurance work, but what about the HIIT’s afterburn effect? How do they compare?
HIIT is high-interval intensity training, one of the most popular types of “efficient” cardio. HIIT or circuit training has also been incorporated in the training of professional athletes, due to its ability to improve both anaerobic and aerobic performance.
Research shows that besides its calorie-burning effect, HIIT can also improve many health markers like VO2max, insulin sensitivity, reduce body fat and improve overall fitness level. (6)
HIIT Routine is usually a circuit session, made up of different full-body exercises, done at vigorous, high intensity for a short period of time. The intensity should reach near maximal effort, around 80-90% of our maximum. In between each exercise, there is a short rest (20 sec. – 2 min.).
HIIT may also be more efficient than long-steady cardio, as research shows it improves both anaerobic and aerobic energy capacity, compared to aerobic training at moderate intensities which improved only aerobic power. (7)
Another study published in The Journal of Obesity found out that high-intensity exercise can stimulate fat-loss, in both normal and overweight individuals. The effect was significant in subcutaneous and abdominal fat, meaning belly-fat reduction is possible. (8) The primary mechanism behind this is increasing energy expenditure and inducing fat oxidation.
The main reason behind HIIT’s ability to affect fat loss so fast is “the afterburn effect”. Interval training at high intensities is known to stimulate extra energy expenditure (aka burn more calories) hours after the workout has finished.
In conclusion, long-steady cardio at moderate intensities, although it can burn more calories in total, it is still inferior to HIIT or high interval intensity training in terms of fat loss. Although longer endurance sessions come with many other cardiorespiratory benefits, HIIT has proven “more effective” time-wise, for fat loss. (9)
HIIT or high-interval intensity training has proven more efficient for fat loss in terms of time spent, compared to long-and-steady cardio.
4. Fasted Cardio | On An Empty Stomach
While this might be a bit extreme for someone who isn’t used to it, fasted cardio might prove superior to regular cardio. The idea is that by training on an empty stomach, you can lose fat faster because you have less glucose for energy. When the body runs out of glucose, fats are the next fuel source. Also, fasted workouts might increase human growth hormone and adrenaline more, which might result in faster fat loss.
Research is mixed on this topic. A study published in the Journal of the International Society of Sports Nutrition found out that both fasted and non-fasted individuals who performed aerobic exercise lost a significant amount of fat mass and weight, with no differences between groups. (10)
From another perspective, intermittent fasting on its own has the potential to speed up weight loss. This comes as a result of fuel-for-energy source switch, and calorie restriction. Matter of fact, intermittent fasting is practically reducing calorie count, as the window for eating is reduced. Also, it allows the body to use ketones (fats) for fuel, rather than just glucose. (11)
Increased fat-oxidation or lipolysis is the primary reason for fat loss. This is how fasting can reduce body weight and fat-oxidation, by limiting the sugar-eating window.
Research shows that fasting can be effective in terms of fat loss and weight loss. However, it looks as if professional athletes or trained individuals don’t really benefit from it. The reason for this lies in metabolism, physiological changes, and hormonal responses. (12)
To conclude, fasted cardio on an empty stomach can be efficient if we train at low-moderate intensity, for a longer duration. This is the aerobic exercise like cycling, swimming, and running, called steady-state cardio. It switches up the fuel source, allowing the body to burn fat for energy instead of glucose.
However, if we pick high-intensity interval training it’s a different story. Especially for athletes, fasted HIIT might cause diminishing returns. HIIT workouts require anaerobic system work, which is not that great and sustainable, as it uses different fuel sources. So, for vigorous activity, the blood sugar levels, hormonal responses, and fuels quantity in a fasted state might disturb proper regeneration.
Either choose a low-moderate activity (steady-cardio) for a longer duration, in a fasted state or choose a HIIT or high-interval intensity training, in a non-fasted state.
5. Do Something Fun
Not much research is needed in this section. In my personal experience, when you do something fun it is a lot more sustainable than doing “pure cardio” with the main goal of losing weight.
It is easier to start doing what’s fun to you, and a lot easier to sustain. The false perspective of cardio, as a “calorie-burning” workout is detrimental in the long run.
Although this is highly individual, I’d encourage you to look up different sports or types of cardio. Some of the most fun types include: boxing, skipping rope, swimming, and skating while many sports like volleyball, football, basketball, and tennis are very effective in terms of weight loss too.
Engaging in sports activities with other people (being social) is more likely to be sustained, as it keeps you accountable, social, it is very fun and slightly competitive. You feel alive, you’re always on the edge, trying to help the team out, to throw that ball or jump higher, for the sake of the game, and not just “to burn calories”.
Whether you choose to run a few laps after the gym, engage in a basketball pickup game, play tennis with your friend or go for one on one football dribbles, pick the type that’s most suitable for you. For the more individually oriented ones, I find boxing and skipping rope to do the trick.
Having fun is the ultimate tool for cardio sustainability, hence why boxing, skipping, and team sports might be the best option, except for individuals oriented in endurance sports.
6. Green Tea + L-Carnitine Supplementation
There’s a broad range of popular weight-loss supplements. Some increase body temperature, some speed up metabolism, other increase energy expenditure, etc. But which one really works? The thing is, although herbs, spices, caffeine can all help, if you’re not in a caloric deficit at the end of the day, weight loss won’t happen.
Caffeine & CLA
Research continually shows that caffeine in green tea can increase fat oxidation. This results in fat loss, but green tea has also many other health benefits related to weight loss. It turns out it suppresses the synthesis of fats (lipids) and increases thermogenesis, thus resulting in increased energy expenditure (calorie-burning). (13)
Another very popular and marketed supplement is CLA. Although the data on its effects on body composition and fat mass reduction isn’t that strong, CLA that comes from foods might be an effective tool to reduce factors related to obesity. (14) However, science isn’t impressed with its effects on weight loss, aside from its anti-obesitic properties.
Another popular fat-burner that might be used in conjunction with green tea, is L-carnitine. An amino acid that transports fats to the mitochondria, for conversion to energy. This decreases the amount of fat stored and it helps reduce visceral or belly fat while providing you with more energy.
A systematic review and meta-analysis published on Pubmed have shown the positive effects of L-carnitine. Supplementing with L-carnitine has proven effective for reducing body weight, body mass index, and fat mass, which is probably the dream combo of anyone trying to lose weight. (15) It was more effective in individuals who are overweight or obese.
Two supplements that may spice up and speed up your weight loss journey are L-carnitine and Green Tea. Although a simple combination, it is the crucial amino acid involved in fat-metabolism, combined with caffeine that can increase fat oxidation.
*Studies have some limitations, important to evaluate the validity of their results. Here’s a highlight of some and NOT ALL studies (and limitation), shown in this article, for context.
Lack of randomization and small sample size *(n)10, (n)20.
- In need of further research specifically suited for endurance athletes *results of untrained males can differ in trained individuals.
- Short duration of study *6 weeks, 4 weeks.
- Aged data or data older than 10 years *2011, 2007, 2005, 1996.
- Further research needed to clarify guidelines and safety of High Intensity Intermittent Exercise Protocol for different types of patients.
- Subjective values due to use of self-reported questionnaires *might reduce data validity.
- Self-reported food intake can vary by 18%.
- Results may be influenced by hormone fluctuations in women who had menstrual cycles.
- Weak control of external factors *diet, sleep, extra activity, regeneration, protein intake etc.
- Studies of CLA on animals may not be sufficient to draw strong conclusions of CLA’s effects in humans.
Frequently Asked Questions
What are the best types of cardio exercises?
Different types of activities which are rhythmic and cyclic, that can be done at a specific tempo/intensity. The best types of cardio include: boxing, swimming, skipping rope, sprinting, hiking, running, cycling, elliptical training etc.
How long should a cardio workout last for?
It heavily depends on the intensity of the activity. Generally, a long steady cardio session would last around 60-120 minutes, done at fairly low intensities, including exercise such as jogging, swimming, cycling or hiking. For more intense activities such as boxing, sprinting, jumping rope, running uphill etc., aiming at 10-20 minutes of total activity can be enough for a good sweaty session.
What are the most common benefits of cardio?
Depending on the type of cardio, its intensity and duration, cardio can be beneficial for: improving circulation, fat-loss and weight management, blood sugar control, energy boost, mood improvement, cholesterol-lowering and stamina.
What warm-up exercise should i do before running?
Exercises that can raise your temperature like light running, an exercise that enhances your ankle stability and mobility, like ankle circles or toes-walk, plus a couple of quads stretches, lunges, and hip rotations. Going slowly into your running session can reduce the amount of lactate build-up, making it easier for you to run next time and regenerate faster.