If you’re a serious lifter between 20 and 40, you’ve likely realized that the “bro-science” passed around the locker room doesn’t always cut it. To truly maximize your physique, you need to look at what the latest data says.

Recent research has debunked several common gym myths, from the “hardgainer” curse to the necessity of post-workout stretching. Here are seven evidence-based insights for your training and nutrition in 2025.

1. The “Hardgainer” Myth Is Officially Dead

Many lifters believe they are genetically “cursed” to stay small. However, a landmark 10-week study has shown that true “non-responders” don’t actually exist. Researchers found that individuals who didn’t gain muscle in one phase of training almost always saw significant growth when they repeated the program or adjusted variables like volume.

The Takeaway: If you aren’t growing, it’s not your DNA—it’s likely your lifestyle, diet, or training volume. Everyone can gain a meaningful amount of muscle; some just need to pay closer attention to the finer details.

This is where tracking becomes critical. SetsApart helps you monitor your hard sets per muscle group, making it easy to identify if insufficient volume is limiting your progress. Check out our guide on the minimum effective dose to learn the baseline volume needed for growth.

2. Lengthened-Bias Training: Overhyped?

The current trend in fitness is “lengthened-bias training”—choosing exercises or machines that are hardest when the muscle is stretched. While it’s popular, a new study using gold-standard MRI showed no significant difference in muscle growth between lengthened-bias and shortened-bias training for muscle groups like the delts, pecs, and glutes.

The Takeaway: Instead of obsessing over specific tension curves, focus on training through a full range of motion. That is a much more reliable way to stimulate growth than trying to “hack” the tension at one specific point. Our article on lifting technique covers the fundamentals that actually matter.

3. Eccentric Training Isn’t the Enemy

It’s a long-held belief that the “eccentric” (lowering) phase of a lift causes significantly more muscle damage and soreness than the “concentric” (lifting) phase. New research suggests this isn’t necessarily true.

When researchers looked at lifters who were equally unfamiliar with both types of movement, they found no significant difference in muscle soreness or recovery time. The “damage” people feel is often just a result of performing a movement they aren’t used to.

The Takeaway: Don’t fear slow eccentrics or negatives. The soreness you experience from new movements typically decreases as your body adapts—it’s not an indicator of excessive damage.

4. Rethink Your Calorie Tracker

If you use MyFitnessPal, you might be getting inaccurate data. A study comparing popular apps to official nutrient databases found that MyFitnessPal often provides low reliability because of inconsistent user-generated entries. In some cases, the error margin for daily calories was as high as 700+ calories.

The Takeaway: For better accuracy, consider using apps like Cronometer or MyNetDiary, which rely on verified official databases rather than crowdsourced (and often inaccurate) information.

5. Don’t Trust AI to Count Your Macros

We all want to just snap a photo of our meal and have AI tell us the macros. Unfortunately, the tech isn’t there yet. Research on models like GPT-4 and Gemini 1.5 Pro showed a mean error rate of 36% for daily calorie intake.

The biggest culprit? Hidden calories. AI cannot “see” the two tablespoons of oil or butter used in a restaurant meal, which can easily add 200+ calories to your total.

The Takeaway: Stick to weighing your food for the best results. While less convenient, manual tracking remains far more accurate than current AI solutions.

6. The 6-Hour Prime: Potentiating Your Performance

Did you know a heavy morning workout could actually make you more athletic in the afternoon? A new study found that 6 hours after a heavy squat session (4 sets of 5 at 85% 1RM), men were actually able to sprint faster and jump higher.

This is due to a “priming” effect where the nervous system is potentiated for high performance once the initial fatigue wears off.

The Takeaway: If you train in the morning and compete or play sports in the afternoon, your morning session might actually enhance your later performance rather than hinder it.

7. Stop Wasting Time on Post-Workout Stretching

If you’re stretching after your lift to prevent soreness or reduce injury risk, you can stop. A meta-analysis of 15 studies concluded that post-workout stretching has no significant effect on muscle soreness or recovery.

Stretching mostly just makes you better at stretching by teaching your nervous system to relax; it doesn’t actually change the physical length of your muscle tissue.

The Takeaway: Reclaim those 10-15 minutes of stretching and use them for additional training volume or simply get home faster. Your recovery won’t suffer.

Bonus: Use Super-Sets for Time Efficiency

To maximize your time in the gym, use agonist-antagonist super-sets (e.g., pairing Bench Press with Rows). Research shows these do not impair muscle growth or strength and allow you to fit more volume into a shorter window.

This technique pairs well with the guidance in our rest between sets guide—strategic rest management can dramatically improve your training efficiency without sacrificing gains.

SetsApart makes tracking super-sets simple. Log your hard sets as you complete them, and the app calculates your weekly volume per muscle group automatically. No complex spreadsheets required.

The Bottom Line

These seven findings share a common theme: focus on the fundamentals that actually drive muscle growth—sufficient volume, progressive overload, and consistent effort—rather than chasing the latest training “hack.”

Track what matters, train hard, and let the science guide your decisions.

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Source

This article was inspired by and summarizes key insights from the following video. Check out the video for more detail and subscribe to the channel—it’s a great resource for evidence-based training.

Watch the full video: 7 Dazzling New Studies For Serious Lifters (2025)