Combining Cardio and Weights: The Right Way to Do Both

"Should I do cardio before or after weights?" I get this question constantly. The answer depends on your goals, but most people get the combination wrong—either skipping one entirely or combining them in ways that sabotage both.

Here's how to effectively train both without undermining your results.

The Core Principle: Priority Determines Order

Whatever matters more goes first, when you're freshest:

If strength/muscle is the priority: Lift first, cardio after or separate day.

If endurance is the priority: Cardio first, lifting after or separate day.

If both are equally important: Separate them as much as possible.

For most recreational exercisers focused on health and body composition, strength should typically be the priority—it's harder to build and more impactful for metabolism.

The Interference Effect Revisited

Concurrent training (doing both cardio and weights) can reduce gains in strength and muscle compared to lifting alone. But the effect is manageable:

Minimal interference:

• Low-intensity cardio (walking, easy cycling)
• Cardio on separate days from lifting
• 6-8+ hours between cardio and lifting

More interference:

• High-intensity cardio (running, HIIT)
• Cardio immediately before lifting
• Cardio focusing on legs (running, cycling at high intensity)

Same-Day Combination: Best Practices

If you must do both on the same day:

Lift first, cardio second:
This preserves strength performance. Cardio after lifting doesn't hurt much—you're already fatigued.

Separate by time if possible:
Morning cardio, evening lifting (or vice versa) gives 6-8+ hours for glycogen replenishment and neural recovery.

Keep post-lifting cardio low-intensity:
Walking, easy cycling, or light rowing. Not HIIT—you're already depleted.

Warm up intelligently:
5-10 minutes of light cardio before lifting is fine and can improve performance. This isn't the "cardio" that interferes.

Weekly Structure Options

Option 1: Separate Days (Best for both goals)

• Monday: Upper body lifting
• Tuesday: Cardio
• Wednesday: Lower body lifting
• Thursday: Cardio
• Friday: Upper body lifting
• Saturday: Cardio
• Sunday: Rest

Option 2: Cardio After Lifting

• Monday: Upper body + 20-min light cardio
• Tuesday: Lower body + 20-min light cardio
• Wednesday: Rest or light cardio only
• Thursday: Upper body + 20-min light cardio
• Friday: Lower body + 20-min light cardio
• Saturday: 30-45 min moderate cardio
• Sunday: Rest

Option 3: AM/PM Split

• Morning: Fasted cardio (20-30 min)
• Evening: Lifting

Option 4: Integrated (Time-Efficient)

• 3 days: Full body lifting
• 2-3 days: Cardio-focused sessions
• Each session: 45-60 minutes total

Cardio Type Matters

Lower interference:

• Walking (including incline)
• Cycling (easy to moderate)
• Swimming
• Rowing (low-moderate intensity)

Higher interference:

• Running (especially high volume)
• HIIT
• Intense cycling/spinning
• CrossFit-style conditioning

If building muscle is important, stick to the lower-interference options.

Fueling for Combination Training

Before lifting: Adequate carbs and protein 2-3 hours prior.

Between sessions (same day): Protein shake and carbs between morning cardio and evening lifting.

Recovery: Higher calorie intake on heavy training days. Don't undereat when doing both.

Common Combination Mistakes

Mistake #1: Long cardio before lifting
Running 5K then expecting to hit PR lifts. Your glycogen is depleted, performance suffers.

Mistake #2: HIIT + heavy lifting same day
Both are demanding on the nervous system. Something suffers.

Mistake #3: Leg-heavy cardio before leg day
Running or cycling intensely, then trying to squat heavy. Recipe for a bad workout.

Mistake #4: Prioritizing cardio for fat loss
Strength training is more important for body composition. Cardio supports, doesn't drive, fat loss.

Mistake #5: Not eating enough
Doing both cardio and weights creates high energy demands. Undereating leads to poor recovery and performance.

For Fat Loss Specifically

If fat loss is the goal, this combination works well:

• 3-4 days: Strength training (preserve muscle)
• Daily: Walking (30-45 min, doesn't impair recovery)
• 1-2 days: Optional HIIT or moderate cardio

The lifting preserves metabolism and muscle. Walking adds calorie burn without the downsides of excessive cardio.

For Muscle Building

If muscle building is the priority:

• 4 days: Strength training (primary focus)
• 2-3 days: Low-intensity cardio (health/recovery)
• Minimal HIIT (competes for recovery)

Keep cardio as a health practice, not a primary focus.

For Endurance + Strength

If both genuinely matter:

• Periodize focus (strength blocks, endurance blocks)
• Or accept compromise (won't maximize either, but can be good at both)
• Higher food intake to support both
• Careful recovery management

Athletes like rowers, CrossFitters, and military personnel often need both. It works but requires careful programming.

My Current Approach

Strength is my priority, cardio is for health:

• 4 days lifting (primary focus)
• Daily walking (30-45 min, often after lifting)
• 1 day moderate cardio (cycling or rowing)

Strength hasn't suffered, cardiovascular health is good, body composition is where I want it.

The Bottom Line

Combining cardio and weights effectively comes down to priority, separation, and modality. Lift first (or on separate days) if strength matters. Use low-impact cardio to minimize interference. If doing both same-day, separate by hours if possible and keep post-lifting cardio easy. Both can coexist without ruining your results—but only with smart programming.