When To Do Cardio for Best Results

Understanding how to combine cardio and strength training into your programme can be confusing.

Should you do cardio before weights? After? On separate days? Does it affect muscle gain? Will it ruin strength progress?

The short answer is that it depends on your goal.

There’s a long-standing belief that cardio should always be performed after strength training, but the reality is a bit more nuanced than that. Research on combining strength and endurance work, often referred to as concurrent training, shows mixed results depending on the type of training performed and the outcome measured.

More importantly, the “best” approach is usually the one that allows you to recover properly, train consistently, and focus on what matters most for your goals.

The Goal Determines The Approach

One of the biggest mistakes people make is trying to optimise everything at once.

If your main goal is to build strength and muscle, your programme should prioritise strength work. If fat loss or cardiovascular fitness is the focus, cardio will naturally play a larger role.

It’s surprising how often people structure their training in ways that work against their primary objective.

At Foundry, we always come back to specificity. Your body adapts to the demands you place on it. This is known as the S.A.I.D principle, Specific Adaptation to Imposed Demands.

In simple terms, the type of training you prioritise is usually the type of result you’ll get.

What The Research Shows

Research comparing strength training, endurance training, and concurrent training generally shows predictable outcomes.

When cardio is included alongside strength work, fat loss tends to improve due to increased overall energy expenditure. When strength training is included, lean muscle mass tends to improve as well.

That’s hardly groundbreaking.

However, some studies suggest that combining high volumes of endurance work with strength training can reduce strength and power gains compared to strength training alone.

This doesn’t mean cardio is “bad” for muscle gain or strength development. It simply means there’s a balance to strike.

If your goal is maximum strength and power development, excessive cardio can interfere with recovery and performance. On the other hand, if your goal is overall health, fitness, and body composition, combining both is usually the best option.

Strength Before Cardio? Usually Yes

From a practical coaching perspective, strength training generally benefits from being performed while you’re fresh.

If you exhaust yourself with high intensity intervals before lifting weights, your performance will suffer. Your output drops, technique deteriorates, and the quality of your session usually declines.

That’s not ideal if strength or muscle gain is your priority.

On the other hand, low intensity cardio such as walking, incline treadmill work, or steady cycling is unlikely to have a major impact on your strength session unless the volume becomes excessive.

This is why, in most cases, we recommend:

Strength training first
Cardio afterwards or separately
Keeping low intensity cardio low stress

Simple.

Not All Cardio Is Equal

People often talk about cardio as though it’s one thing, but there’s a big difference between:

A 20 minute incline walk
A hard interval session on the assault bike
A 10km run
A recovery spin session

The impact on recovery and performance varies massively.

High intensity interval training creates a much greater recovery demand than steady-state cardio. That matters when you’re also trying to progress your strength work.

If your programme already includes several hard training sessions per week, adding multiple intense cardio sessions on top can quickly become too much.

More isn’t always better.

Cardio For Fat Loss

One of the most common reasons people add cardio is to lose fat.

And yes, cardio can help.

It increases overall calorie expenditure, improves cardiovascular fitness, and can support recovery when programmed properly. However, cardio alone is rarely the answer.

Nutrition remains the biggest driver of fat loss.

You can’t out-train consistently poor eating habits, which is why we always encourage members to build solid nutritional habits alongside training. Portion control, protein intake, food quality, and consistency matter far more than endlessly adding cardio sessions.

If you’re struggling with this balance, our article on
Eating Healthily but Not Losing Fat? goes deeper into why effort doesn’t always equal results.

Recovery Matters More Than People Think

The biggest issue with combining lots of cardio and strength work isn’t usually the sessions themselves. It’s recovery.

Your body has only a limited capacity to adapt.

If your sleep, nutrition, and stress management aren’t supporting your training load, your performance will eventually drop. You start feeling flat, motivation dips, and progress slows down.

This is especially important for people trying to do everything at once:

Lift heavy
Run frequently
Train six days a week
Diet aggressively

There’s a limit to how much quality work you can recover from.

At Foundry, we’d rather see someone train consistently with a sensible balance than constantly push themselves into the ground.

The Best Approach For Most People

For most people, the goal isn’t elite strength performance or marathon preparation.

It’s usually:

Improve body composition
Build strength
Increase fitness
Feel healthier
Have more energy

For those goals, combining strength and cardio works extremely well when programmed intelligently.

A balanced week might include:

Three to four strength sessions
Two to three cardio sessions
Daily movement like walking

That gives you the benefits of both without compromising recovery too heavily.

Be Sensible With Your Priorities

If you’re limited on time, focus on the things that give you the biggest return for your goal.

If building strength and muscle is the priority, don’t waste your best energy on endless cardio beforehand.

If improving cardiovascular fitness is your main goal, then cardio naturally deserves more focus.

Trying to maximise everything simultaneously usually leads to mediocre progress across the board.

Clarity matters.

Cardio and Strength Can Work Together

The debate between cardio and weights often becomes unnecessarily black and white.

The reality is that both have enormous benefits.

Strength training improves muscle mass, joint health, resilience, and long-term health outcomes. Cardio improves heart health, work capacity, recovery, and energy expenditure.

The key is understanding how to combine them properly based on your goals, recovery capacity, and lifestyle.

That’s where good coaching and structured programming make all the difference.

Train With Purpose

There’s no universal rule that says cardio must always happen before or after weights.

The better question is: what are you trying to achieve?

Once you answer that, your programme becomes much easier to structure.

At Foundry, we focus on building programmes that are realistic, sustainable, and aligned with your goals. That means balancing strength, conditioning, recovery, and lifestyle in a way that keeps you progressing long term.

Because the best training plan isn’t the one that looks hardest on paper.

It’s the one you can recover from, stay consistent with, and continue doing for years.

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