The Dr. Shannon Show

Episode: Body Recomposition Capsule #3: How Heavy to Lift
Host: Dr. Shannon Ritchey, PT, DPT
Date: January 3, 2026

Episode Overview

In this third installment of the Body Recomposition Capsule series, Dr. Shannon Ritchey discusses a nuanced and science-based answer to the popular question: “How heavy do I need to lift to build muscle?” The episode dismantles common myths about “lifting heavy,” explains how to tell if you’re truly challenging your muscles, and provides clear, actionable guidelines for choosing the right load and rep range—regardless of your equipment, experience, or age.

Key Discussion Points & Insights

1. Defining Mechanical Muscle Failure

• Mechanical muscle failure is reached when your muscle can’t complete another rep with good form, even with maximal effort (03:26).

• It’s not always necessary to train to absolute failure; stopping 1–3 reps shy can yield the same muscle growth (“hypertrophy”).

  Shannon (03:59): “Studies show that you don’t have to train all the way to that point. You can actually stop anywhere from one rep shy of true failure all the way up to about three reps shy of true failure and see the exact same hypertrophy or muscle gain.”

2. How to Know If You’re Close Enough to Failure

• Slowing rep speed: If your reps are still quick at the end, you’re probably not near failure.

• Feeling “stuck”: Reps feel slow/grinding at the hardest part; this indicates proximity to failure.

• The “Rest Test”: Pause five seconds after your last rep and try again; if you can do 3+ reps easily, you weren’t near failure.

  Shannon (06:05): “If you can immediately do three reps or more, you were not close enough to failure… training close to failure means that you recruit a high percentage of your muscle, including your type 2 muscle fibers.”

3. The Stimulating Reps Model

• The last few reps near failure generate the greatest growth stimulus.

• If you stop too early, you miss targeting large, growth-prone fibers.

  Shannon (07:13): “If you stop shy of those last few reps, you never tap into those larger muscle fibers, and therefore the set isn’t very effective for muscle growth.”

4. Common Mistakes Hindering Muscle Growth

a) Breaking Mid-Set (08:11)

• Shaking out or resting mid-set delays muscle fiber recruitment and reduces effectiveness.

• Instead of pausing, end the set when you feel the urge to stop.

  Shannon (09:14): “Think of those last few reps as the ones that turn the key… every time you break, you’re essentially hitting the reset button.”

b) Confusing Mental with Muscular Fatigue (10:09)

• Burn or discomfort is not the same as reaching muscle failure; many group classes are hard but not effective for muscle gain because sets are abandoned at the burn, not true fatigue.

  Shannon (11:00): “You stop because of the discomfort of the burn, so you stop long before the muscle is actually near its limit.”

c) Predetermining Rep or Set Counts (12:21)

• Rigidly sticking to numbers like “3 sets of 10” results in picking weights that are too light.

• Instead, select a challenging weight and aim for failure, not a specific count.

  Shannon (13:51): “It’s not about hitting a certain number of reps perfectly. It’s about getting close to your muscle failure.”

d) Choosing Weights Too Light (15:00)

• If you can do 30+ reps with a load, it’s too light to spark muscle growth—aim for failure under 30 reps.

5. So, How Heavy Do You Need to Lift?

• You do NOT need to lift stereotypically “heavy” weights. Bodyweight and lighter loads can work if you reach failure within 4–30 reps.

• The “strength-hypertrophy-endurance continuum” is outdated: muscle can grow across a broad rep range, not just 8–12 reps.

  Shannon (16:34): “We now know that you can build muscle anywhere from about 4ish reps all the way up to about 30 reps, as long as you take that set close to failure.”

• Time under tension matters: Growth is maximized when a set lasts between 20–70 seconds before reaching failure.

6. Choosing Rep Ranges: Pros & Cons

• Low reps (4–7): Good for advanced lifters, time-pressed workouts, and maximal strength. Mental fatigue/burn is minimized.

• Moderate reps (8–15): The “sweet spot” for most people; balance of challenge, safety, and results.

• High reps (15–30): Ideal for beginners or those limited to lighter equipment, but risk of “burning out” mentally before actual muscle failure.

  Shannon (20:26): “Unless you’re in a lifting competition… what we care about is that [higher reps taken close to failure will] build enough strength that will be meaningfully impactful to your daily life and longevity.”

• If you can do more than 30 reps or hold an exercise for over 70 seconds, the load is too light for meaningful muscle growth.

7. Guidance for Midlife & Menopausal Women (22:20)

• Ignore blanket rules requiring “super heavy” weights—anyone can build muscle in the 4–30 rep range if they push close to failure, regardless of age or hormonal status.

  Shannon (22:44): “As long as your sets are challenging enough, those can build muscle—even if you are perimenopause, post-menopause.”

8. Choosing the Best Exercises

• Isolation over combination: Focus on one muscle group per movement for maximum load and safety. Bootcamp-style combos (e.g., lunge + curl) compromise stimulus.

• Stable set-ups = more effective training: Use the floor, wall, bench, or chair. Stability enables you to target the true muscle limit without balance or coordination as limiting factors.

  Shannon (25:55): “Stability and using the floor, using a wall, using a bench—it’s not cheating. It actually makes the lift more effective and can give you better strength carryover.”

Memorable Quotes

• On lifting for muscle gain

  “It’s not the weight you’re holding—it’s the effort and proximity to failure that counts.” (28:10)

• On stable exercises

  “Your brain isn’t bouncing all over the place trying to coordinate your movement… you’re able to recruit more motor units and take the muscle closer to failure.” (26:40)

• On breaking during sets

  “Every time you break, you’re essentially hitting the reset button, so you never quite reach the zone that stimulates change.” (09:17)

Timestamps for Key Segments

• [03:26] Mechanical muscle failure explained
• [06:05] The “rest test” for failure
• [07:13] The stimulating reps concept
• [08:11] Breaking mid-set: why it’s counterproductive
• [10:09] Distinguishing mental vs. muscular fatigue
• [12:21] The problem with predetermined rep/set goals
• [15:00] Using loads that are too light
• [16:34] Debunking the “hypertrophy range” myth
• [20:26] Choosing your rep range: what really matters
• [22:20] Advice for women 40+ and during menopause
• [24:43] Importance of isolation and stability in exercise selection
• [25:55] Stable set-ups boost effectiveness
• [28:10] Recap and final advice

Takeaway Summary

• You do not need to lift “heavy” to build muscle—train any movement to near failure in the 4–30 rep range, focusing on effort, not absolute weight.
• Avoid common pitfalls: don’t break mid-set, don’t let discomfort or boredom end a set too soon, and don’t be bound by arbitrary rep counts.
• Strength and muscle growth are stimulated by pushing close to true muscular fatigue, not mental fatigue or burn.
• Prioritize stable, single-muscle-group exercises for the safest and most effective results.

Up Next:
The series continues with a capsule on training frequency, set recommendations, and finding your minimum effective dose for lasting results.