Cardio for Fat Loss: The Science-Based Guide

Cardio is controversial. Some say it's essential for fat loss. Others say it kills gains. The truth, as usual, is somewhere in between.

Here's what science actually says about cardiovascular exercise.

The Role of Cardio in Fat Loss

The Basic Equation

Fat loss = Calories Out > Calories In

Cardio increases calories out. But so does:

• Strength training
• Walking
• Daily activity (NEAT)
• Simply eating less

Cardio is a tool, not a requirement.

When Cardio Helps

• You've already reduced calories significantly
• You want to eat more while maintaining deficit
• You enjoy cardio activities
• You have cardiovascular health goals

When Cardio Isn't Necessary

• You can create deficit through diet alone
• You're new to training (focus on lifting first)
• You hate cardio and it reduces adherence

Types of Cardio

LISS (Low-Intensity Steady State)

What it is: Continuous activity at 50-65% max heart rate for 30-60+ minutes.

Examples: Walking, easy cycling, swimming laps

Pros:

• Low recovery cost
• Can do frequently
• Less appetite stimulation
• Good for beginners

Cons:

• Time-consuming
• Lower calorie burn per minute

MISS (Moderate-Intensity Steady State)

What it is: Continuous activity at 65-75% max heart rate for 20-40 minutes.

Examples: Jogging, elliptical, moderate cycling

Pros:

• Balanced time-to-calorie ratio
• Good cardiovascular benefits

Cons:

• Higher recovery cost than LISS
• Can interfere with leg training

HIIT (High-Intensity Interval Training)

What it is: Alternating periods of intense effort (85-95% max heart rate) and recovery.

Examples: Sprint intervals, rowing intervals, cycling intervals

Pros:

• Time-efficient
• EPOC (continued calorie burn post-exercise)
• Improves power and explosiveness

Cons:

• High recovery cost
• Can't do frequently
• Not for beginners
• Can increase appetite

The HIIT vs. Steady-State Debate

What Research Shows

When calories burned are equated, both produce similar fat loss. HIIT isn't magic—it's just time-efficient.

The Real Factors

• Recovery capacity: HIIT requires more recovery
• Training schedule: Don't do HIIT before leg day
• Preference: What will you actually do consistently?
• Time available: HIIT saves time if you're busy

Practical Recommendation

Mix both:

• 2-3 LISS sessions per week (walking, incline treadmill)
• 1-2 HIIT sessions per week (if recovery allows)

Common Cardio Myths

Myth 1: Fasted Cardio Burns More Fat

Reality: Fat loss over 24 hours is the same whether you eat before cardio or not. Do whatever feels better and helps you perform.

Myth 2: Cardio Kills Gains

Reality: Excessive cardio can interfere with muscle growth, but moderate cardio doesn't. The interference effect is overblown for most people.

Myth 3: The Fat-Burning Zone

Reality: Working at lower intensity burns a higher percentage of fat, but fewer total calories. Higher intensity burns more total calories and more total fat.

Myth 4: You Must Do Cardio to Lose Fat

Reality: Cardio is optional. Diet creates the deficit; cardio can help but isn't required.

Myth 5: More Cardio = More Results

Reality: Beyond a point, more cardio just increases hunger, fatigue, and recovery needs. There's an optimal dose.

How Much Cardio Do You Need?

For General Health

• 150 minutes moderate activity weekly, OR
• 75 minutes vigorous activity weekly
• Can be accumulated in short bouts

For Fat Loss

• Start with diet first
• Add cardio gradually as needed
• 2-4 sessions per week is usually sufficient
• Increase only when fat loss stalls

For Cardiovascular Fitness

• 3-5 sessions per week
• Mix of intensities
• Progressive overload applies to cardio too

Programming Cardio with Strength Training

Scheduling

• Separate cardio and lifting by 6+ hours if possible
• If same session: lift first, then cardio
• Put HIIT far from leg training

Volume Considerations

• Start low: 2 sessions per week
• Add gradually based on recovery
• Monitor strength performance
• Reduce if lifts are suffering

Recovery Signals

Signs you're doing too much cardio:

• Decreased strength in gym
• Excessive fatigue
• Increased hunger beyond normal
• Poor sleep
• Mood changes

Best Cardio Methods for Lifters

1. Walking

Low recovery cost, can do daily, burns decent calories at high volumes. 10,000 steps is a great target.

2. Incline Treadmill

Higher calorie burn than flat walking, still low impact. 15% incline, 3.0 mph.

3. Rowing

Full body, low impact, effective. Great for HIIT intervals.

4. Cycling

Easy on joints, good for LISS or HIIT. Doesn't interfere much with upper body training.

5. Swimming

Zero impact, full body, but requires skill and pool access.

Worst Options for Lifters

• Long-distance running (high interference effect)
• Excessive HIIT (recovery demand)
• Cardio machines that mimic lifting movements (hack squat machine for cardio)

Creating Your Cardio Plan

Step 1: Establish Goals

• Fat loss? General health? Endurance event?
• Goals determine approach

Step 2: Assess Schedule

• How many sessions can you realistically do?
• When can you fit them around lifting?

Step 3: Start Conservative

• 2 sessions per week
• Mix of LISS and moderate intensity
• 20-30 minutes per session

Step 4: Progress as Needed

• Add duration before frequency
• Add frequency before intensity
• Only increase when needed for results

Step 5: Monitor and Adjust

• Track performance
• Watch recovery
• Adjust based on results

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Track your cardio sessions with FORGE - Habits & Fitness. Log duration, intensity, and watch your conditioning improve alongside your strength gains.