How to Spot Bad Fitness Advice (5-Step Framework & Red Flags)

You see one fitness influencer swear that fasted cardio burns more fat. Another says it makes no difference. A third claims it destroys muscle. All three have six-packs and hundreds of thousands of followers.

Who's right?

This scenario plays out every day in fitness. Everyone sounds confident, but they can't all be correct. Research from Flinders University found that more than 60% of fitness content on TikTok contains incorrect or harmful information. The study examined 200 popular videos and found that much of the misleading content came from fitness influencers with little to no formal training in health or exercise science.

You deserve better than guesswork. This guide gives you a framework to evaluate any fitness advice before you waste months following the wrong plan.

Why fitness advice feels so confusing

The fitness industry has an information problem, not an information shortage.

Every day, thousands of new workout videos, blog posts, and training programs flood social media. Most of it contradicts something else you saw yesterday. The problem isn't that you're missing the secret formula. The problem is too many people selling different formulas with the same level of confidence.

Fitness results take weeks or months to show up. By the time you realize advice was trash, you've wasted months of training. You can't test fitness claims the way you test whether your coffee tastes good.

The credential gap makes this worse. A University of Glasgow study examined nine top UK fitness bloggers and found only one could back up their claims with evidence. Just one. The rest built audiences of hundreds of thousands by sounding authoritative, not by knowing what they're talking about.

Blake Baxter, a performance coach at Banner Sports Medicine, doesn't sugarcoat it: "Many of these influencers don't have any formal education and aren't equipped to give information or advice regarding exercise or fitness."

But follower count and credentials don't always correlate. Some of the most qualified trainers have small audiences, while some of the least qualified have millions. Your Instagram feed won't tell you who to trust.

What good fitness advice looks like

Good fitness guidance has five characteristics.

It's evidence-based

The person can point to research, studies, or established training principles. They don't just say "trust me" or "this worked for me." They explain why something works based on how your body functions.

It's personalized to context

Good trainers ask questions before prescribing solutions. Your training age, injury history, schedule, and goals all matter. Anyone giving blanket advice to everyone is oversimplifying.

It stays within scope

Certified trainers can design workout programs. They cannot diagnose injuries, prescribe meal plans (unless they're also registered dietitians), or treat medical conditions. Quality professionals know their boundaries.

It's realistic about timelines

Muscle growth happens slowly. Fat loss happens slowly. Research shows that beginners can expect about 1-2 pounds of muscle gain per month, while sustainable fat loss is 0.5-1% of body weight per week. Visible muscle growth typically takes 4-12 weeks. Anyone promising dramatic results in unrealistic timeframes is lying to you.

It cites sources

Credible trainers reference research to back up their methods. They don't just say "this worked for me." They explain why it works and point to evidence.

If you want guidance that follows these principles, Forge uses evidence-based training principles to create personalized programs that adapt to your progress.

Decoding fitness credentials

Not all certifications carry the same weight. Some are legitimate, respected qualifications that require real study. Others are weekend courses that hand out certificates like participation trophies.

The gold standard is NCCA accreditation. The National Commission for Certifying Agencies evaluates certification programs to ensure they meet professional standards. If a certification isn't NCCA-accredited, it's not worth much.

The "Big Four" NCCA-accredited certifications

• NASM (National Academy of Sports Medicine) - Focuses on corrective exercise and movement assessment
• ACE (American Council on Exercise) - Broad, accessible, covers general population training
• ACSM (American College of Sports Medicine) - Strong scientific foundation, respected in clinical settings
• NSCA (National Strength and Conditioning Association) - Strength and conditioning focus, popular among performance coaches

These certifications require actual study, passing comprehensive exams, and continuing education to maintain. They're not perfect, but they establish a baseline of competence.

Degrees in exercise science, kinesiology, or related fields add credibility, especially when combined with practical experience. But education alone doesn't make someone a good coach. You want someone who has both knowledge and the ability to apply it.

10 red flags that scream "ignore this advice"

1. Guaranteed results in specific timeframes

"Lose 20 pounds in 30 days" or "add 2 inches to your arms in 6 weeks" are marketing lies. Your body doesn't work on a promotional calendar.

2. One-size-fits-all programming

If they're giving identical advice to a 22-year-old athlete and a 55-year-old beginner, they're not coaching. They're copy-pasting.

3. No warm-up or mobility work

Greg Robins, a strength and conditioning coach, says: "If a trainer doesn't assess you from the start, don't hire him." Programs that skip warm-ups or don't address mobility are incomplete at best, dangerous at worst.

4. Prescribing specific meal plans without RD credentials

Personal trainers can offer general nutrition guidance. They cannot create detailed meal plans, recommend supplements as treatment, or provide medical nutrition therapy unless they're also registered dietitians. This is both a legal and safety issue.

5. Extreme approaches

Cutting out entire food groups, training twice a day every day, or drastically slashing calories aren't sustainable. Extreme approaches work briefly, then fail spectacularly. Good trainers build sustainable habits.

6. Dismissing basic principles

Progressive overload, adequate recovery, and proper nutrition aren't optional. Anyone claiming you don't need these fundamentals is wrong.

7. No discussion of form or technique

If someone demonstrates an exercise without explaining setup, execution, or common mistakes, they're teaching you to move, not teaching you to move well. Form matters.

8. Selling supplements as requirements

Supplements are optional additions to a solid foundation. If someone's entire program revolves around buying their supplement stack, they're salespeople first, trainers second.

9. Before-and-after photos as primary evidence

Photos prove nothing about method quality. Lighting, angles, timing, and individual genetics create dramatic transformations that may have little to do with the program itself. Photos sell, but they don't validate.

10. Defensive responses to questions

Good trainers welcome questions and explain their reasoning. If someone gets defensive, dismissive, or aggressive when you ask why they recommend something, that's a character problem that predicts future issues.

When experts contradict each other

Sometimes qualified experts genuinely disagree. This doesn't mean one is wrong and one is right. It often means both approaches work, just differently.

Take training frequency. Some respected coaches program full-body workouts three times per week. Others prefer body-part splits with five or six training days. Both approaches build muscle when executed properly. The "best" choice depends on your schedule, recovery capacity, and preferences.

The contradiction becomes a red flag when it involves established fundamentals. No legitimate expert argues against progressive overload. None claim you can out-train a terrible diet. None recommend skipping recovery entirely. When someone contradicts bedrock principles, they're either ignorant or selling something.

Context matters too. A recommendation that works for competitive athletes might be terrible for beginners. Advice optimized for fat loss differs from advice for muscle gain. If experts contradict each other but are addressing different populations or goals, that's not really a contradiction.

Your 5-step framework to evaluate any advice

Stop guessing. Use this systematic approach.

Step 1: Check credentials

Look for NCCA-accredited certifications or relevant degrees. Search their background. If you can't find any credentials, proceed with extreme caution. Learn how to find a qualified trainer.

Step 2: Evaluate the claim

Does it promise unrealistic results? Does it contradict established principles? Does it sound too good to be true? If yes to any of these, you already have your answer.

Step 3: Look for red flags

Review the 10 warning signs above. One red flag might be forgivable. Multiple red flags mean walk away.

Step 4: Check scope

Is this person qualified to give this specific advice? A great strength coach might give terrible nutrition advice. A skilled yoga instructor might know nothing about powerlifting programming. Match the advisor to the advice type.

Step 5: Cross-reference

See what other credible sources say about the same topic. Consensus among qualified professionals means something. One person with a revolutionary approach that contradicts everyone else is usually wrong, not enlightened.

This framework works whether you're evaluating an Instagram fitness influencer, a local gym trainer, or an expensive online program.

Trust the process, question the source

You shouldn't need a PhD in exercise science to figure out who to trust. But you do need standards.

The fitness industry makes money from confusion. Contradicting advice keeps you buying new programs, trying new methods, and second-guessing yourself. Breaking this cycle starts with learning to evaluate sources instead of just consuming content.

Check credentials. Watch for red flags. Demand evidence. Ask questions. These habits protect you from wasting months on programs that were never going to work.

Still deciding if you need a personal trainer? If you're tired of sorting through contradicting advice and want a training approach built on evidence instead of hype, Forge offers AI-powered personal training that adapts to your progress and follows proven principles. No gimmicks, no unrealistic promises, just intelligent programming that meets you where you are.

Your time and effort matter too much to waste on bad guidance. Use this framework. Protect your progress. Train smarter.