“Comfort is the enemy of progress”… one of the most important lessons I’ve learned over my years of training. 

You’ve been there too, right? Going through your leg day, doing the same old routine, and wondering why your quads aren’t growing like you want them to. 

The fact is: Just stopping when it hurts, not when you physically can’t do another rep, is the main reason you’re not growing. Going to failure – to the rep you fail at – is the key to muscle growth. 

So, to help you grow and learn how to push yourself to failure, I’m sharing three leg extension intensifiers which will transform your quad development in just 10 minutes. 

I recently tested these with my partner Ali (@consciouslivingwithali), and let’s just say, she wasn’t exactly thanking me afterward.

Before you begin these intensity techniques, let’s make sure you’re performing leg extensions correctly. Despite the simple nature of this exercise, it’s often performed incorrectly.

 The part most people miss is: getting a full stretch in the quads between each rep. 

I firmly grip the handles on the side of the seat, to make sure my body is as stable as possible. This allows me to generate more force with my legs.  Then to create a stretch in my quads before starting the movement, I slide my hips slightly forward.  You should feel your quads lengthening before you even start the concentric phase. 

When driving up, focus on squeezing your quads at the top, then control the weight on the way down. You don’t need to be bouncing at the top or the bottom, we’re not trying to launch into orbit here. The controlled negative allows our muscles to stretch, contributing to our muscular growth.  

The first mistake most people make is stopping when it burns, not at actual failure. There’s a massive difference.

When Ali hit what she thought was failure at rep 20, I pushed her for two more. And, she got them. “Most people stop when it hurts,” I explained to Ali after her set. “You only stop when you physically cannot go anymore.”

Those extra reps are exactly where growth happens – where your mind wants to quit but your muscles can still perform. Your body adapts to the stress you place on it, and it needs to reach true failure to trigger maximum adaptation. 

If you’re short on time, then cluster sets are your new best friend (and worst nightmare).

Here’s how they work:

• Choose a weight you can lift for 8-10 reps
• Perform those reps with perfect form
• Rest for 5-10 seconds (not enough for full recovery)
• Repeat the next set for another 8  reps
• Continue this pattern until you cannot hit 8 reps on a set 

I managed four mini-sets before my legs were completely toast. 

After you’ve completed your working sets, it’s time for what I call the “Bodybuilding Vegan Leg Extension Extravaganza.” 

Here’s how you do it:

• Perform a set to failure with a challenging weight (15+ reps)
• Immediately perform 5 half-reps (top half of the movement)
• Without rest, perform 5 quarter-reps
• Finish with a 5-second isometric hold at the bottom position

When Ali tried this, her reaction said it all: “I hate you right now.” Mission accomplished.

Although machines may display the same weight, not all stacks are created equal. If you’re traveling and jumping between different gyms, use these tips to stay safe and still crush your leg extensions:

• Start with a very light weight for 8 reps
• Add a small amount of weight (10 to 20 lbs)
• Perform another 8 reps
• Continue adding weight until you can no longer complete 8 clean reps

“This is humbling because you use a lighter weight and still get wrecked,” I explained after demonstrating. This techique is much safer than jumping straight into heavy weights.

In just 10 minutes, we’ve covered three ways to absolutely destroy your quads. These techniques will remind you what true intensity feels like.

Want to see these intensifiers in action? Watch the full video here!