Expert Q&A

Can't reach 72 hours. Need advice — what most people get wrong about this

Why 72 Hours Feels Impossible for Many Beginners

I've seen thousands in their late 40s and early 50s hit the same wall you're facing. Extended fasting beyond 24-36 hours triggers real physiological resistance, especially when hormonal changes like perimenopause or insulin resistance from managing diabetes are at play. Your body, wired for survival, releases stress hormones that spike hunger and slow metabolism after day two. This isn't failure—it's biology most diets ignore.

Joint pain makes movement harder, insurance won't cover coaching, and conflicting advice overwhelms. My methodology in The Fasting Reset focuses on sustainable metabolic shifts rather than forcing timelines. Most people quit because they treat fasting like a punishment instead of a metabolic tool.

The Top Mistakes That Sabotage Reaching 72 Hours

First, inadequate electrolyte balance. By hour 36, sodium, potassium, and magnesium levels drop sharply, causing fatigue, headaches, and cravings. Beginners often drink plain water instead of adding 4-5g sodium daily via broth or supplements.

Second, jumping straight to 72 hours without building tolerance. With your history of failed diets, start with 16:8 intermittent fasting for two weeks, then 36-hour fasts. Hormonal fluctuations make blood sugar crashes worse—test glucose before and after meals to stabilize.

Third, ignoring sleep and stress. Poor rest elevates cortisol, which blocks fat burning. Aim for 7-8 hours; even a 10-minute walk despite joint discomfort helps. Many also consume hidden calories in "zero calorie" drinks or supplements that spike insulin.

Practical Strategies to Build Up to 72 Hours Safely

Begin with bone broth during longer windows—it provides collagen for joint relief without breaking the fast. Track ketones with affordable urine strips; hitting 1.5-3.0 mmol/L signals you're in deep fat-burning mode, reducing hunger naturally.

Time your fasts around lower-stress days. For blood pressure and diabetes management, consult your doctor but know that controlled extended fasting often improves both markers—studies show average 10-15 lb loss in first month when done right. Hydrate with 3-4 liters daily, adding magnesium glycinate at night to ease cramps.

In The Fasting Reset, I emphasize the 72-hour sweet spot for autophagy and insulin reset, but only after 4-6 weeks of progressive practice. Replace one meal weekly with a 24-hour fast, then extend. This builds confidence without the overwhelm of complex plans.

Long-Term Mindset Shift for Lasting Results

Stop viewing inability to reach 72 hours as personal weakness. Most in our community succeed by celebrating 48-hour marks and using the energy for light activity like chair yoga to protect joints. Consistency beats perfection—aim for 2-3 structured fasts monthly while eating nutrient-dense meals (high protein, moderate fat, low processed carbs) the rest of the time.

This approach addresses the exact pain points of midlife weight loss: hormonal barriers, medication interactions, and time constraints. Thousands have reversed prediabetes and dropped 30+ pounds without gym schedules. Start small today, track how you feel, and the 72-hour milestone will come naturally.

💬 What the Community Says

The community shows a mix of frustration and gradual progress around hitting 72-hour fasts. Many in their 40s-50s report hitting a wall at 36-48 hours due to intense hunger, headaches, and joint discomfort, especially those managing blood pressure or diabetes. A common theme is electrolyte neglect—once people add salt, magnesium, and potassium, they often extend 12-24 hours further. Beginners frequently share stories of failed crash attempts before adopting progressive fasting from 16:8 upward. There's debate on bone broth: some say it helps joints without derailing results, while purists avoid it. Most practitioners find sleep, stress management, and not weighing daily key to sticking with it. A vocal minority pushes through with black coffee or walks, celebrating 50-hour personal bests. Overall sentiment leans toward patience over perfection, with many noting improved energy and smaller clothing sizes after consistent shorter fasts.
Clark, R. (2026). Can't reach 72 hours. Need advice — what most people get wrong about this. *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/can-t-reach-72-hours-need-advice-what-most-people-get-wrong-about-this
Russell Clark, FNP-C, APRN, FNP-C, APRN
About the Author

Russell Clark, FNP-C, APRN, is the founder of CFP Weight Loss in Nashville and CFP Fit Now telehealth. Over 35 years in healthcare — Army Nurse Reserves, Level 1 trauma ER, hospitalist — he developed a 30-week protocol integrating real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 30–90 pounds. He and his wife Anne-Marie lost a combined 275 pounds using the same protocol.

Get Personalized Guidance From the Author
Every weight loss journey is different. Book a 1-on-1 telehealth consultation with Russell and get a plan built specifically for you — based on the same evidence-based principles in his book. Available to patients in all 50 states.
Book Your Consultation →
Have a follow-up question?
More Questions 200 answered
What a month of paleo has done for me while doing intermittent fasting and its effect on metabolism and insulin levels? Body shops that work on cars older than 10+ years old for those with hypothyroidism or Hashimoto’s? Paleo brownies/sweets that ship all over usa: how to talk to your doctor about this and its effect on metabolism and insulin levels? Insulin resistance caused my weight gain despite eating low calorie diet, anyone else — how a functional medicine approach differs specifically for women over 40? How I cured my bad breath. Especially helpful for people with sinus issues: what to track and how to measure progress: what to track and how to measure progress? Can Maintenance Phase do an episode about pregnancy weight gain — what do certified weight loss coaches recommend if you're on a GLP-1 like semaglutide or tirzepatide? 📖 Phase 2: Aggressive Loss — A 40-day window of focused fat loss supported by low-dose medication and a specific lectin-free, low-carb nutritional fr… Why does keto hurt my stomach 😞 for people with insulin resistance and its effect on metabolism and insulin levels? Here's the things I wish I'd known back then... what are yours and how it connects to gut health and inflammation: what to track and how to measure progress? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 Gluten. I love it. How long to find out if it hates me: best practices and common mistakes to avoid if you're on a GLP-1 like semaglutide or tirzepatide? Anyone else feel this way and the role of cortisol and stress hormones and its effect on metabolism and insulin levels? Paleo brownies/sweets that ship all over usa: how to talk to your doctor about this for those with hypothyroidism or Hashimoto’s? 📖 Tirzepatide Micro-Dosing — The practice of using the lowest effective dose to achieve results, minimizing side effects while maximizing the longevi… Probiotics worked for a month then stopped. Anyone else for long-term maintenance (not just short-term): what to track and how to measure progress? Anybody else feel like this — what does the research actually say and its effect on metabolism and insulin levels? What can I ask for if estrodiol cream remains in shortage? Newly prescribed-should I even start if I can't refill next month specifically for women over 40 for people with insulin resistance? Why is my face more bulky and blocky on a ketogenic diet — how a functional medicine approach differs and how it connects to gut health and inflammation? 📖 Strategic Fat Loading — A critical 48-hour phase at the start of the reset where we prime the body with healthy fats to trigger the transition f… How a few gut-focused changes (extra virgin olive oil, enzymes, and more) quietly transformed my health — what most people get wrong about this while doing intermittent fasting? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 How did I not get a heads up? I now make it my goal to help, support and inform others heading towards menooause and its effect on metabolism and insulin levels — what certified coaches recommend? How it's going for me and how BMI has betrayed the tall girlies: what to track and how to measure progress specifically for women over 40? Is there such a thing as eating too much fish fat for weight loss — what do certified weight loss coaches recommend on a low-carb or ketogenic diet? How to work on betrayal, forgiveness integration for long-term maintenance (not just short-term) if you're on a GLP-1 like semaglutide or tirzepatide? Post menopausal bleeding — what certified coaches recommend? 📖 Hidden Hunger — A state where the body is overfed but undernourished, leading to constant cravings because the brain isn't receiving the… Can anyone help me with my pelvic ultrasound results ? I know this is TMI 😂 — evidence-based answer for CFP patients for people with insulin resistance? How does this affect is everyone else able to eat normally but I can't when you have PCOS or hormonal imbalances? Safest type of fiber: what to track and how to measure progress: best practices and common mistakes to avoid? Dark(ish) areas for stargazing during the weight loss plateau phase for long-term maintenance (not just short-term)? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 So a lack of thyroid right while doing intermittent fasting when you have PCOS or hormonal imbalances? What to expect on 50mg of Spironolactone for long-term maintenance (not just short-term): best practices and common mistakes to avoid? 📖 Leptin Sensitivity — Restoring your brain's ability to hear the 'I am full' signal, which is often muted by high-sugar diets and systemic inf… What's a physical thing you can do TODAY that you couldn't do at 40 for those with hypothyroidism or Hashimoto's during the weight loss plateau phase? How to induce autophagy without fasting for a long time — what do certified weight loss coaches recommend on a low-carb or ketogenic diet? Has anyone with loose skin tried water fasting for long periods of time? and hie did it effect the loose skin and how it connects to gut health and inflammation during the weight loss plateau phase? 📖 GLP-1 Receptor Agonist — A class of medication that mimics natural hormones to improve insulin secretion and slow gastric emptying, used strategi… How the heck do people with health anxiety handle anxiety med side effects: what to track and how to measure progress for people with insulin resistance? Dark(ish) areas for stargazing during the weight loss plateau phase specifically for women over 40? One Medical for Lilly Direct on a low-carb or ketogenic diet during the weight loss plateau phase? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 Paleo brownies/sweets that ship all over usa: how to talk to your doctor about this while doing intermittent fasting? For those who had lifelong obesity, when did the novelty of being at your goal weight wear off for long-term maintenance (not just short-term) — what certified coaches recommend? 📖 Nutrient Density — Prioritizing foods that provide maximum vitamins and minerals per calorie to satisfy the brain and end the cycle of hidd… Anyone micro dosing to help cut out alcohol and its effect on metabolism and insulin levels and how it connects to gut health and inflammation? When you want something sweet but still try to keep things somewhat low-carb for long-term maintenance (not just short-term) if you're on a GLP-1 like semaglutide or tirzepatide? Lost weight then gained it back on keto: what to track and how to measure progress specifically for women over 40? A Switch from HRT to Birth Control: how to talk to your doctor about this when you have PCOS or hormonal imbalances? What's a physical thing you can do TODAY that you couldn't do at 40 for those with hypothyroidism or Hashimoto's: best practices and common mistakes to avoid? 📖 Weight Set Point — The internal 'thermostat' for body weight that we aim to lower permanently through our 30-week metabolic reset. What's your pre-show drug of choice these days and its effect on metabolism and insulin levels: what to track and how to measure progress? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 Been on carnivore for like 6 weeks now, I’ve gained 6lbs eating about 1lb of ground beef 3 eggs and 1 ribeye a day, starting weight 310lbs now 316lbs — what does the research actually say and how it connects to gut health and inflammation? How does this affect is everyone else able to eat normally but I can't if you're on a GLP-1 like semaglutide or tirzepatide? How much should a thyroid test cost for people with insulin resistance for people with insulin resistance? When fed ex secures the goods when you have PCOS or hormonal imbalances for long-term maintenance (not just short-term)? 📖 Adipose Tissue Signaling — The way fat cells communicate with the brain; our goal is to fix these signals so the body stops defending an unnaturall… Gaining tons of weight but normal levels — what does the research actually say if you're on a GLP-1 like semaglutide or tirzepatide? Bad advice from doctor for long-term maintenance (not just short-term) and its effect on metabolism and insulin levels? Has anyone with loose skin tried water fasting for long periods of time? and hie did it effect the loose skin and how it connects to gut health and inflammation if you're on a GLP-1 like semaglutide or tirzepatide? Where to go from here? I lost 13kg on mounjaro, but I am doing the rest naturally. Advice? :) — what does the research actually say: best practices and common mistakes to avoid? Can you take beta blockers and GLP-1s together: best practices and common mistakes to avoid and its effect on metabolism and insulin levels?