This week we are looking at which forms of Cardio are valid in which situations for the purpose of maximum Fat loss. Cardio for fitness and performance is a separate article, we are just concentrating on Fat loss.
Here’s a science-based breakdown focusing on the primary goals of fat loss, sustainability and muscle retention. Fat loss is driven primarily by sustained energy deficit, not by the specific cardio style. Having said that some cardio styles will suit different situations, so let us look at what the science is currently saying about which Cardio style is best for each situation.
1. Low-intensity steady state (LISS)
Examples: walking, easy cycling, incline treadmill
What science shows
- High fat oxidation during exercise
- Low stress, low injury risk
- Easy to recover from and repeat frequently, minimal interference with weight training
- Excellent for adherence, can be done daily
- Great for appetite control in many people
LISS is one of the most reliable tools for fat loss, mainly because people can do a lot of it consistently (Sustainability).
2. Step counting (NEAT)
Steps are a proxy for non-exercise activity thermogenesis (NEAT).
Evidence highlights
- NEAT can vary by up to 2,000 kcal/day between individuals
- Step increases often don’t trigger compensatory hunger like formal cardio can
- Correlates strongly with long-term fat loss maintenance
Why steps work so well
- Low perceived effort and cortisol release
- Doesn’t “feel” like exercise
- Scales easily (6k → 8k → 10k+)
Step count is arguably the most underrated fat-loss lever in the literature.
3. Moderate-intensity cardio (Zone 2–3)
Examples: jogging, tempo cycling, rowing
What science shows
- Good balance of calories burned and sustainability
- Improves mitochondrial density and metabolic flexibility
- Burns more total calories per unit time than LISS
- Strong cardiovascular benefits
Disadvantage is it can interfere with leg recovery if overused and some people can experience a big jump in appetite.
4. HIIT (high-intensity interval training)
Examples: sprints, assault bike intervals
This form of cardio is starting to venture more into improvements in fitness rather than pure fat burning. This is not a bad thing at all, it just starts to veer away from our main goal of improving/maintaining muscle mass and burning fat.
This style of cardio can be enjoyable for some people, you can get a good sweat up, improve VO2 max and have a real sense that you got stuck in and burned some calories. Sprints can increase the risk of injury, so gradually extend yourself and slowly build up each HIIT session.
Experts like Dr Peter Attia suggest tacking on a 3-minute-high intensity session on the end of a regular cardio session as a way of increasing VO2 max. Research shows people with strong muscles and a good VO2 max aren’t about to die anytime soon.
5. Fasted cardio (popular but misunderstood)
Fasted cardio has been shown to have Higher fat oxidation during exercise due to lower glycogen availability. However there appears to be no consistent advantage in 24-hour or long-term fat loss. Some people experience reduced performance, and the naturally higher cortisol can easily lead to increased muscle protein breakdown.
Who should avoid it
- Resistance-trained individuals prioritising muscle retention
- High-intensity cardio sessions
- Anyone already highly stressed, sleeping poorly or under-recovered
Fasted cardio is a preference tool, with a few small tweaks, we can make it work for us (see how I use fasted cardio in Part B).
Final takeaway
The science is remarkably straight forward, no new amazing discoveries, a lot of common sense really. The best cardio for fat loss is the one you can repeat consistently, recover from, and not get injured doing. Counting steps and just being active throughout the day appears to suite the most people and is a great way to consistently shed body-fat.
Part B: What I’m Doing
I was pleasantly surprised when I was researching what the latest science was suggesting with cardio. Often there is a lag on what bodybuilders do and what the science says, however at this point in time we are in agreement.
· Counting Steps: The goal is to burn fat while maintaining muscle mass and the hands down winner for that is Counting Steps. As I sit on a computer most days, if I don’t make an effort to move then steps come in at around 5K. The first goal was small and was to bump it up to an 8K minimum. That worked a little, so after a few weeks that went up to 10K per day, where fat loss started to become more noticeable. Over the past 16 weeks I’ve gradually crept it up to 14K, which for me takes a concerted daily effort to sneak extra steps in or walk the long way to the car.
· Fasted Cardio: my cardio first thing in the morning is not technically fasted as I have a scoop of WPI 15-20 minutes before I start to drop cortisol levels down in my body. The muscles might burn some of that WPI as fuel during cardio, just as long as the muscles don’t consume themselves. With the WPI I’ll add some electrolytes and enough fat burner/pre-workout to give me 100mg caffeine.
· Moderate-intensity cardio (Zone 2–3): jogging on the spot or around the house is a form of cardio that I utilize daily. It clocks steps up faster than walking, isn’t too taxing on joints or leg recovery. I do notice that a big chunk of jogging the day before Leg Day reduces my strength on the compound movements, it makes sense and is an easy fix. Regular walking steps the night before leg day, otherwise some light jogging is a good way to rack the steps up faster and free up a little bit of time.
Part C: What I suggest you do
The only modification I would make to you guys would be the volume that I am currently doing. Here is a quick check list to get you started on your cardio/fat burning regime.
1. Check your steps to see where they currently are. If they are less than 7K, try 8K steps per day for 1 week and see what happens, if you don’t notice much change, try 9K for the 2nd week. If you are already doing over 12K steps in a routine day, then I would suggest that your cardio is fine and nutrition is to blame. Drop 20% of your calories
5. Fasted cardio is a preference, I like it because it gets some cardio out of the way, I can shower then head off to work with 6K steps done. Choice of fasted cardio is a time thing for me. Adding in some Zone 2-3 cardio is good for fitness, try to mix it up, don’t just do treadmill all the time.
Consistency is the key, make it as enjoyable as possible. Catch up with a friend and go for a walk along the beach, good company, some fresh air and you burn some fat too.