If you’re new to the gym, it’s totally normal to ask:
“Should I start with cardio or lift weights first?”
The fitness world is full of opinions — some say always do cardio first to “warm up,” others swear by lifting heavy before anything else. But here’s the real truth, especially if you’re a skinny guy or someone trying to gain muscle:
⚠️ If you have a fast metabolism or struggle to gain weight — cardio should NOT come first. Period.
🔥 The Short Answer:
✅ If your goal is to build muscle, gain strength, or bulk up:
Do weights first. Always.
❌ If you’re naturally skinny or have a fast metabolism:
Avoid doing intense cardio before weights — it’ll hurt your gains.
🧠 Why Lifting Weights Comes First for Muscle Growth
When you lift weights, your body uses energy (glycogen) stored in your muscles to power through sets. If you burn all that energy doing cardio first, your muscles won’t have what they need to train hard and grow.
Here’s what happens if you do cardio before weights:
🪫 You’ll be weaker during your workout
❌ You might not hit progressive overload (which is key to growth)
🚫 You could even lose weight — the opposite of what skinny guys need
“When I was skinny, I made this mistake early on — running before weights. I felt drained, small, and made no progress. Once I flipped it — weights first, short cardio last — I started gaining fast.”
— Muscle Products Store Team
⚖️ But What If I Want to Do Both?
You can still include cardio — and for general health, you should. But the order (and type) matters.
✅ Best approach for beginners trying to build muscle:
Warm up: 5–10 mins of light cycling, walking, or rowing
Lift weights: Full focus, progressive overload, proper form
Post-workout (optional): 10–20 mins of light-moderate cardio (e.g. incline walk, bike)
This keeps your energy focused on muscle-building and uses cardio as a finisher — not a strength killer.
❗ Cardio to Avoid First If You’re a Skinny Beginner:
❌ Long runs before lifting
❌ HIIT or high-intensity circuits pre-workout
❌ Fasted cardio if you’re already struggling to eat enough
These will just eat into your muscle gains and leave you looking and feeling flat.
💪 The Right Way to Train as a Beginner (Especially if You’re Skinny)
If your goal is muscle growth, this should be your training priority:
Start with a solid workout plan focused on strength training
👉 Try our Beginner Gym Workout PlanEat in a calorie surplus every day
👉 Use our Diet for Skinny Guys to Build Muscle
Mass gainers, snacks, and frequent meals will be your best friendsUse smart supplements to recover and train harder
- Mass Gainers
Aminos and Bcaas
👉 Explore our best beginner supplements
Add cardio AFTER weights if you still want to include it
Or do cardio on a separate rest day, but keep it light
🤔 When Should Cardio Come First?
The only time beginners should do cardio first is if:
Your goal is weight loss or fat burning
You’re doing a cardio-focused session (like a spin class or endurance run)
You’re not worried about strength or muscle building
Otherwise — especially for skinny guys — weights always come first.
🧠 Final Answer: Cardio or Weights First for Beginners?
✅ Want to gain muscle? Weights first, cardio after
❌ Skinny with a fast metabolism? Avoid cardio before lifting at all costs
💪 Trying to get strong and grow? Focus your energy on lifting
🔄 Still want cardio? Do it after weights or on rest days
