The evidence behind every suggestion.

Estimating resting energy expenditure

Start from Mifflin–St Jeor for resting energy; it is the most accurate predictive equation for most adults, but it is still an estimate (often within about 10%).

Of the common predictive equations, Mifflin–St Jeor predicts measured resting metabolic rate within 10% in the largest share of non-obese and obese adults. Individual error remains, so it is a starting point that the person's own intake and weight trend should replace.

Limits: Less accurate for very muscular people, older adults and some ethnic groups.

• Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247. doi:10.1093/ajcn/51.2.241
• Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775-789. doi:10.1016/j.jada.2005.02.005

Read more: How to find your real maintenance calories

Measured maintenance beats formulas

Once there are a few weeks of food logs and weigh-ins, the maintenance implied by the person's own weight trend overrides any formula or activity multiplier.

Activity multipliers and wearable calorie estimates carry large individual errors. Energy balance means the weight trend against logged intake reveals actual expenditure; that measured number is more accurate for the individual than any population equation, as long as logging is reasonably complete. The two are combined by how precise each is: a noisy scale or patchy log keeps the estimate nearer the formula for longer.

Limits: Only as good as the food log; consistent under-logging biases it low.

• Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837. doi:10.1016/S0140-6736(11)60812-X
• Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775-789. doi:10.1016/j.jada.2005.02.005

Read more: How to find your real maintenance calories, How to tell if your fat loss has really stalled

Weight change is not linear

Treat ~7700 kcal per kg as a first approximation only: weight loss slows over time as body mass and expenditure fall, so targets are corrected from the measured trend rather than assumed.

The static "3500 kcal per pound" rule overstates long-term loss because expenditure falls as weight falls, and some adaptive thermogenesis occurs. Dynamic models fit real data much better. A closed loop that compares the planned and measured rate is the practical answer.

• Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837. doi:10.1016/S0140-6736(11)60812-X
• Trexler ET, Smith-Ryan AE, Norton LE. Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr. 2014;11:7. doi:10.1186/1550-2783-11-7

Read more: How to find your real maintenance calories, Why your weight jumps around from day to day, How to tell if your fat loss has really stalled, How fast to lose fat without losing muscle

Energy in protein, carbohydrate, fat and alcohol

Count about 4 kcal per gram of protein and of carbohydrate, 9 per gram of fat and 7 per gram of alcohol; a drink's calories are mostly its alcohol, so never rebuild them from carbohydrate and protein alone.

The general Atwater factors used by the Dietary Reference Intakes and food labels. They are averages: fibre and some proteins yield a little less, but the error is small next to portion estimates. Ethanol supplies about 7 kcal per gram, so a 500 ml lager has more energy from alcohol than from carbohydrate.

Limits: Averages across foods; labels may use specific factors.

• Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academies Press; 2005. doi:10.17226/10490

Unsupervised calorie floor

Never set a weight-loss target below about 1200 kcal/day for women or 1500 kcal/day for men without medical supervision, and never more than 30% below maintenance.

The 2013 AHA/ACC/TOS adult obesity guideline prescribes 1200–1500 kcal/day for women and 1500–1800 kcal/day for men when an individualised deficit is not used. Lower intakes (very-low-calorie diets) belong under medical supervision. Laroa adds a relative floor of 70% of maintenance so large or active people are not cut too hard.

Limits: The 30%-of-maintenance limit is Laroa's conservative policy, not a guideline number.

• Jensen MD, Ryan DH, Apovian CM, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults. Circulation. 2014;129(25 Suppl 2):S102-S138. doi:10.1161/01.cir.0000437739.71477.ee

Read more: How to tell if your fat loss has really stalled, How fast to lose fat without losing muscle

Low energy availability (REDs)

Persistent fatigue, falling performance, frequent illness or injury, or lost or irregular periods during a deficit or heavy training are warning signs of low energy availability: ease the deficit and suggest a clinician, never push harder.

Energy availability below about 30 kcal per kg of fat-free mass per day disrupts reproductive and metabolic hormones within days. The IOC consensus on Relative Energy Deficiency in Sport describes effects on bone, hormones, immunity, mood and performance, in men and women.

• Loucks AB, Thuma JR. Luteinizing hormone pulsatility is disrupted at a threshold of energy availability in regularly menstruating women. J Clin Endocrinol Metab. 2003;88(1):297-311. doi:10.1210/jc.2002-020369
• Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med. 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994

Read more: How to tell if your fat loss has really stalled, How fast to lose fat without losing muscle

Rate of fat loss

Aim to lose about 0.5–1% of bodyweight per week; slower for people who are already lean, to keep muscle and performance.

In trained people, losing about 0.5–1% of bodyweight a week preserves lean mass better than faster loss; leaner people sit at the slower end. Faster loss is reasonable only for people with a lot of fat to lose, and under supervision.

• Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014;11:20. doi:10.1186/1550-2783-11-20

Read more: Why your weight jumps around from day to day, How fast to lose fat without losing muscle

Rate of gain while building muscle

When building muscle, gain about 0.25–0.5% of bodyweight per week; beginners can sit at the top, advanced lifters at the bottom. Faster gain is mostly fat.

Muscle can only be added slowly, so a small surplus captures most of the benefit. Larger surpluses mainly add fat that later has to be lost.

• Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports. 2019;7(7):154. doi:10.3390/sports7070154

Read more: How fast to lose fat without losing muscle

Daily weight noise

Day-to-day scale changes are mostly water, glycogen and gut content; judge progress on a smoothed trend over at least two weeks, never on one weigh-in.

Each gram of stored glycogen binds roughly three grams of water, so carbohydrate, salt, training and the menstrual cycle move the scale by a kilogram or more in days without any change in fat. Trends from frequent weigh-ins filter this noise.

• Kreitzman SN, Coxon AY, Szaz KF. Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition. Am J Clin Nutr. 1992;56(1 Suppl):292S-293S. doi:10.1093/ajcn/56.1.292S
• Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837. doi:10.1016/S0140-6736(11)60812-X

Read more: How to find your real maintenance calories, Why your weight jumps around from day to day, How to tell if your fat loss has really stalled, Weekly check-in questions for personal trainers, What to track for your clients between sessions

Daily protein for people who train

For muscle gain with resistance training, about 1.6 g/kg/day captures most of the benefit and up to 2.2 g/kg/day covers nearly everyone; more is safe for healthy people but not needed.

A meta-regression of 49 trials found gains in lean mass plateau around 1.6 g/kg/day (95% CI up to about 2.2). The ISSN position stand recommends 1.4–2.0 g/kg/day for most exercising people.

Limits: People with kidney disease need their clinician's protein target.

• Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384. doi:10.1136/bjsports-2017-097608
• Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8

Read more: How much protein you need to build muscle, Gym supplements with real evidence behind them

Protein while losing fat

In a calorie deficit, keep protein high (about 1.8–2.7 g/kg bodyweight, i.e. 2.3–3.1 g/kg of fat-free mass) to protect muscle.

Lean-mass loss during a deficit is reduced by higher protein, especially for lean, trained people in larger deficits.

• Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014;11:20. doi:10.1186/1550-2783-11-20
• Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8

Read more: How much protein you need to build muscle, How fast to lose fat without losing muscle

Protein timing and distribution

Total daily protein matters far more than timing; spreading it over 3–4 meals of roughly 0.3–0.4 g/kg is sensible, but there is no narrow post-workout "anabolic window".

When total intake is matched, protein timing has little to no effect on hypertrophy. The ISSN suggests 20–40 g doses every 3–4 hours as a practical pattern; a 2023 trial showed the body uses large single doses (100 g) too, just over a longer time.

• Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013;10:53. doi:10.1186/1550-2783-10-53
• Aragon AA, Schoenfeld BJ. Nutrient timing revisited: is there a post-exercise anabolic window? J Int Soc Sports Nutr. 2013;10:5. doi:10.1186/1550-2783-10-5
• Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8
• Trommelen J, van Lieshout GAA, Nyakayiru J, et al. The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans. Cell Rep Med. 2023;4(12):101324. doi:10.1016/j.xcrm.2023.101324

Read more: How much protein you need to build muscle

Protein for older adults

Adults over 65 need at least 1.0–1.2 g/kg/day of protein, and more (≥1.2) when active, to limit age-related muscle loss.

The PROT-AGE group recommends 1.0–1.2 g/kg/day for healthy older adults and higher intakes for those who exercise or are ill, except with severe kidney disease.

• Bauer J, Biolo G, Cederholm T, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc. 2013;14(8):542-559. doi:10.1016/j.jamda.2013.05.021

Read more: How much protein you need to build muscle

Dietary fat

Keep fat between 20% and 35% of calories; going much below 20% for long periods offers no fat-loss advantage and is linked to lower testosterone in men.

The acceptable macronutrient distribution range for fat is 20–35% of energy. Intervention studies show low-fat diets modestly lower testosterone in men compared with higher-fat diets.

• Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academies Press; 2005. doi:10.17226/10490
• Whittaker J, Wu K. Low-fat diets and testosterone in men: systematic review and meta-analysis of intervention studies. J Steroid Biochem Mol Biol. 2021;210:105878. doi:10.1016/j.jsbmb.2021.105878

Carbohydrate

Carbohydrate fuels hard and long training: roughly 3–5 g/kg/day for moderate training and 5–7 g/kg/day for about an hour a day of moderate-to-hard work; with calories and protein equal, low-carb diets give no extra fat loss.

The ACSM/AND/DC position scales carbohydrate with training load, up to 8–12 g/kg/day for very high endurance volume. Controlled feeding studies show no meaningful fat-loss advantage of low-carbohydrate diets when calories and protein are matched.

• Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine joint position statement: nutrition and athletic performance. Med Sci Sports Exerc. 2016;48(3):543-568. doi:10.1249/MSS.0000000000000852
• Hall KD, Guo J. Obesity energetics: body weight regulation and the effects of diet composition. Gastroenterology. 2017;152(7):1718-1727. doi:10.1053/j.gastro.2017.01.052

Fibre

Aim for about 14 g of fibre per 1000 kcal (roughly 25–35 g/day) from whole grains, legumes, fruit and vegetables.

Higher fibre intakes (25–29 g/day or more) are associated with lower all-cause mortality, heart disease, type 2 diabetes and colorectal cancer, with dose-response benefits.

• Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academies Press; 2005. doi:10.17226/10490
• Reynolds A, Mann J, Cummings J, et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019;393(10170):434-445. doi:10.1016/S0140-6736(18)31809-9

Overall eating pattern

Favour a Mediterranean-style pattern (vegetables, fruit, legumes, whole grains, nuts, olive oil, fish) built on mostly minimally processed foods; no single food is required or forbidden.

A Mediterranean-style diet has randomised-trial evidence for fewer cardiovascular events. An inpatient trial found ultra-processed diets led people to eat about 500 kcal/day more than minimally processed diets matched for presented nutrients.

• Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts. N Engl J Med. 2018;378(25):e34. doi:10.1056/NEJMoa1800389
• Hall KD, Ayuketah A, Brychta R, et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab. 2019;30(1):67-77. doi:10.1016/j.cmet.2019.05.008

Meal frequency

Meal frequency does not change fat loss when calories are equal; choose the number of meals that makes intake and protein easiest to hit.

A meta-analysis found no meaningful effect of meal frequency on weight or body composition once energy intake is controlled.

• Schoenfeld BJ, Aragon AA, Krieger JW. Effects of meal frequency on weight loss and body composition: a meta-analysis. Nutr Rev. 2015;73(2):69-82. doi:10.1093/nutrit/nuu017

Hydration

Drink to limit sweat losses to under about 2% of bodyweight in long or hot sessions, but do not overdrink: gaining weight during exercise risks hyponatraemia.

Fluid deficits over about 2% of bodyweight impair endurance performance in the heat. Replacing more than is lost can dilute blood sodium; the ACSM recommends individualised plans based on sweat rate.

• Sawka MN, Burke LM, Eichner ER, et al. American College of Sports Medicine position stand: exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377-390. doi:10.1249/mss.0b013e31802ca597

Training volume

Muscle growth rises with weekly hard sets per muscle (about 10+ beats under 5), with diminishing returns; add sets only when recovery and progress allow.

A dose-response meta-analysis found higher weekly set volumes produced more hypertrophy, with 10 or more sets per muscle per week outperforming fewer than 5. Gains taper at higher volumes and individual tolerance varies, so volume should be added gradually and pulled back when performance stalls.

• Schoenfeld BJ, Ogborn D, Krieger JW. Dose-response relationship between weekly resistance training volume and increases in muscle mass: a systematic review and meta-analysis. J Sports Sci. 2017;35(11):1073-1082. doi:10.1080/02640414.2016.1210197
• American College of Sports Medicine. Position stand: progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708. doi:10.1249/MSS.0b013e3181915670

Read more: How many sets per muscle per week to grow

Load and rep range

Muscle grows similarly across a wide rep range (about 5–30 reps) when sets are taken close to failure; heavier loads (about 1–6 reps) are better for maximal strength.

Low- and high-load training produce similar hypertrophy when effort is high, while high loads produce greater one-rep-max gains. Rep ranges are tools for comfort, joint tolerance and strength specificity, not magic zones.

• Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training: a systematic review and meta-analysis. J Strength Cond Res. 2017;31(12):3508-3523. doi:10.1519/JSC.0000000000002200
• Lopez P, Radaelli R, Taaffe DR, et al. Resistance training load effects on muscle hypertrophy and strength gain: systematic review and network meta-analysis. Med Sci Sports Exerc. 2021;53(6):1206-1216. doi:10.1249/MSS.0000000000002585

Read more: How many sets per muscle per week to grow

Effort and proximity to failure

Train most working sets about 0–3 reps from failure; going to absolute failure every set adds fatigue for little extra growth, and strength gains need even less proximity.

Hypertrophy is greater as sets end closer to failure, but the difference between stopping 1–2 reps short and true failure is small while fatigue is higher. Reps in reserve (RIR) is a practical, validated way to rate this.

• Refalo MC, Helms ER, Trexler ET, Hamilton DL, Fyfe JJ. Influence of resistance training proximity-to-failure on skeletal muscle hypertrophy: a systematic review with meta-analysis. Sports Med. 2023;53(3):649-665. doi:10.1007/s40279-022-01784-y
• Helms ER, Cronin J, Storey A, Zourdos MC. Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Strength Cond J. 2016;38(4):42-49. doi:10.1519/SSC.0000000000000218

Read more: How many sets per muscle per week to grow, When to deload, and how to tell you need one, What to track for your clients between sessions

Training frequency

With weekly volume equal, training a muscle 1 or 3 times a week gives similar results; about twice a week is a practical way to spread the sets.

Meta-analyses show frequency has little independent effect on hypertrophy or strength once total volume is equated; higher frequency mainly helps to fit more quality volume.

• Schoenfeld BJ, Ogborn D, Krieger JW. Effects of resistance training frequency on measures of muscle hypertrophy: a systematic review and meta-analysis. Sports Med. 2016;46(11):1689-1697. doi:10.1007/s40279-016-0543-8
• Grgic J, Schoenfeld BJ, Davies TB, et al. Effect of resistance training frequency on gains in muscular strength: a systematic review and meta-analysis. Sports Med. 2018;48(5):1207-1220. doi:10.1007/s40279-018-0872-x

Read more: How many sets per muscle per week to grow

Progression

Progress gradually: add reps first, then load in small steps (about 2–10%) once the top of the rep range is reached at the target effort.

The ACSM recommends increasing load by 2–10% when a person can perform the current workload for one to two reps beyond the target on consecutive sessions. Double progression implements this.

• American College of Sports Medicine. Position stand: progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708. doi:10.1249/MSS.0b013e3181915670

Read more: How to track progressive overload week to week, What to track for your clients between sessions

Rest between sets

Rest about 2–3 minutes or more on heavy compound lifts; very short rests reduce the work you can do and the gains that follow.

In trained men, 3-minute rests produced more strength and hypertrophy than 1-minute rests. Shorter rests suit isolation and conditioning work.

• Schoenfeld BJ, Pope ZK, Benik FM, et al. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. J Strength Cond Res. 2016;30(7):1805-1812. doi:10.1519/JSC.0000000000001272
• American College of Sports Medicine. Position stand: progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708. doi:10.1249/MSS.0b013e3181915670

Read more: How many sets per muscle per week to grow

Exercise variation

Keep main lifts long enough to progress them; constantly changing exercises ("muscle confusion") adds nothing, while some variation for weak points or joints is fine.

Systematic review evidence shows moderate, planned variation can help regional growth, but excessive or random rotation impairs strength progress.

• Kassiano W, Nunes JP, Costa B, et al. Does varying resistance exercises promote superior muscle hypertrophy and strength gains? A systematic review. J Strength Cond Res. 2022;36(6):1753-1762. doi:10.1519/JSC.0000000000004258

Read more: How to track progressive overload week to week

Deloads and lighter weeks

Reduce volume or intensity for a week when performance, readiness and effort ratings say fatigue has built up; deload timing is expert practice, not a fixed rule backed by trials.

Varying training stress is a core principle of the ACSM progression models, and short reductions in volume are widely used to dissipate fatigue. Controlled trials of deload timing are few, so Laroa triggers lighter weeks from the person's own signals rather than a calendar.

• American College of Sports Medicine. Position stand: progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708. doi:10.1249/MSS.0b013e3181915670

Read more: When to deload, and how to tell you need one

Estimated one-rep max

Estimated 1RM from rep maxes (e.g. Epley) is reliable for sets of about 10 reps or fewer and increasingly inaccurate above that; treat it as a trend, not an exact max.

Validation studies show prediction equations track true 1RM well at low reps, with errors growing with rep count and differing between lifts.

• LeSuer DA, McCormick JH, Mayhew JL, Wasserstein RL, Arnold MD. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. J Strength Cond Res. 1997;11(4):211-213. doi:10.1519/00124278-199711000-00001

Read more: How to track progressive overload week to week

Sudden load increases

A sudden jump in weekly training load compared with the recent habit is worth a caution, but workload ratios are not validated injury predictors; never claim they predict injury.

Rapid increases in load relative to what an athlete is prepared for are associated with injury in some cohorts, but the acute:chronic workload ratio has statistical flaws and should not be used to forecast an individual's risk.

• Gabbett TJ. The training-injury prevention paradox: should athletes be training smarter and harder? Br J Sports Med. 2016;50(5):273-280. doi:10.1136/bjsports-2015-095788
• Impellizzeri FM, Tenan MS, Kempton T, Novak A, Coutts AJ. Acute:chronic workload ratio: conceptual issues and fundamental pitfalls. Int J Sports Physiol Perform. 2020;15(6):907-913. doi:10.1123/ijspp.2019-0864

Injury prevention

Strength training is the best-supported exercise for reducing sports injuries; static stretching before exercise has not been shown to prevent them.

A meta-analysis of randomised trials found strength training cut sports injuries to under a third, proprioception training roughly halved them, and stretching showed no protective effect.

• Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. Br J Sports Med. 2014;48(11):871-877. doi:10.1136/bjsports-2013-092538

Activity for health

For health, adults should get 150–300 min of moderate or 75–150 min of vigorous aerobic activity a week, plus muscle strengthening on at least 2 days.

The WHO 2020 guidelines; more activity gives additional benefit and any amount is better than none. Reducing sedentary time is also recommended.

• Bull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med. 2020;54(24):1451-1462. doi:10.1136/bjsports-2020-102955

Fasted cardio

Fasted cardio does not cause more fat loss than fed cardio when daily calories are equal; do it fasted or fed by preference and performance.

A trial in women on a matched deficit found no difference in fat loss between fasted and fed aerobic training.

• Schoenfeld BJ, Aragon AA, Wilborn CD, et al. Body composition changes associated with fasted versus non-fasted aerobic exercise. J Int Soc Sports Nutr. 2014;11:54. doi:10.1186/s12970-014-0054-7

Sleep

Adults need at least 7 hours of sleep a night regularly; consistent short sleep is a reason to ease training stress, not to push through.

The AASM and Sleep Research Society recommend 7 or more hours for adults; regular short sleep is associated with poorer health, performance and recovery.

• Watson NF, Badr MS, Belenky G, et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep. 2015;38(6):843-844. doi:10.5665/sleep.4716

Read more: Low HRV today? When to train and when to ease off

HRV and resting heart rate

Read HRV and resting heart rate against the person's own rolling baseline over several days; single readings are noisy and should not change training alone.

Rolling averages of HRV relative to an individual baseline track adaptation and fatigue better than single-day values, which vary with sleep, alcohol, illness and measurement conditions.

• Plews DJ, Laursen PB, Stanley J, Kilding AE, Buchheit M. Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring. Sports Med. 2013;43(9):773-781. doi:10.1007/s40279-013-0071-8

Read more: When to deload, and how to tell you need one, Low HRV today? When to train and when to ease off

How you feel before training

Simple self-ratings of sleep, soreness and energy reflect how someone is coping with training at least as well as objective markers; on a day they are poor, keeping sets a rep further from failure is a low-cost way to ease off.

A systematic review of 56 studies found self-reported wellbeing responded to acute and chronic training load, often more sensitively than blood markers, heart rate or performance tests. Stopping a rep or two short of failure costs little growth while lowering fatigue (training.proximity_to_failure).

Limits: Which ratings to ask and the one-extra-rep adjustment are Laroa's practical choice; the review does not set cut-offs.

• Saw AE, Main LC, Gastin PB. Monitoring the athlete training response: subjective self-reported measures trump commonly used objective measures: a systematic review. Br J Sports Med. 2016;50(5):281-291. doi:10.1136/bjsports-2015-094758
• Refalo MC, Helms ER, Trexler ET, Hamilton DL, Fyfe JJ. Influence of resistance training proximity-to-failure on skeletal muscle hypertrophy: a systematic review with meta-analysis. Sports Med. 2023;53(3):649-665. doi:10.1007/s40279-022-01784-y

Read more: When to deload, and how to tell you need one, Low HRV today? When to train and when to ease off, Weekly check-in questions for personal trainers, What to track for your clients between sessions

Training with pain

Mild discomfort that settles by the next day can be acceptable in rehab-style training; sharp, worsening or lingering pain means stop that movement and see a clinician. Laroa holds loading from 4/10 pain.

In chronic musculoskeletal pain, exercise that allows some pain has small short-term benefits over pain-free exercise, which is why pain-monitoring models tolerate mild symptoms. Acute, sharp or escalating pain is different and needs assessment.

Limits: The 4/10 hold line is Laroa's conservative policy.

• Smith BE, Hendrick P, Smith TO, et al. Should exercises be painful in the management of chronic musculoskeletal pain? A systematic review and meta-analysis. Br J Sports Med. 2017;51(23):1679-1687. doi:10.1136/bjsports-2016-097383

Read more: Low HRV today? When to train and when to ease off, Weekly check-in questions for personal trainers, What to track for your clients between sessions

Creatine

Creatine monohydrate (3–5 g/day) is the best-supported supplement for strength and muscle gain and is safe for healthy people; loading is optional.

The ISSN position stand reviews hundreds of studies showing improved high-intensity performance and training adaptations, with no adverse effects in healthy people at recommended doses.

Limits: People with kidney disease should ask their clinician first.

• Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. doi:10.1186/s12970-017-0173-z

Read more: Gym supplements with real evidence behind them

Caffeine

Caffeine (about 3–6 mg/kg, roughly 60 minutes before) reliably improves performance; avoid it late in the day if it disturbs sleep.

The ISSN position stand finds consistent ergogenic effects across endurance, strength and power at moderate doses, with large individual variation and side effects at high doses.

Limits: Pregnancy, heart conditions and some medications need lower limits or a clinician's advice.

• Guest NS, VanDusseldorp TA, Nelson MT, et al. International Society of Sports Nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18:1. doi:10.1186/s12970-020-00383-4

Read more: Gym supplements with real evidence behind them

Other supplements

Beyond protein powder for convenience, creatine and caffeine, most supplements (test boosters, fat burners, BCAAs with adequate protein) lack good evidence; food first.

The ISSN review grades most marketed supplements as having little or no evidence of benefit. BCAAs add nothing when daily protein is adequate.

• Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. doi:10.1186/s12970-018-0242-y

Read more: Gym supplements with real evidence behind them

Symptoms that need a clinician

Chest pain or pressure, fainting, unusual breathlessness, palpitations or dizziness during exercise mean stop and get medical advice before training again.

ACSM pre-participation screening asks anyone with signs or symptoms of cardiovascular, metabolic or renal disease to get medical clearance before continuing or starting exercise.

• Riebe D, Franklin BA, Thompson PD, et al. Updating ACSM's recommendations for exercise preparticipation health screening. Med Sci Sports Exerc. 2015;47(11):2473-2479. doi:10.1249/MSS.0000000000000664

Read more: Low HRV today? When to train and when to ease off, Weekly check-in questions for personal trainers

“You must have protein within 30–60 minutes after training or you lose the gains.”

Total daily protein matters most; with normal meals before and after training the timing effect is negligible.

The evidence: Protein timing and distribution

• Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013;10:53. doi:10.1186/1550-2783-10-53
• Aragon AA, Schoenfeld BJ. Nutrient timing revisited: is there a post-exercise anabolic window? J Int Soc Sports Nutr. 2013;10:5. doi:10.1186/1550-2783-10-5

“The body can only use about 30 g of protein per meal.”

Larger doses are used too, just over a longer period; spreading protein is convenient, not required.

The evidence: Protein timing and distribution

• Trommelen J, van Lieshout GAA, Nyakayiru J, et al. The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans. Cell Rep Med. 2023;4(12):101324. doi:10.1016/j.xcrm.2023.101324
• Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8

“Training a body part (e.g. crunches for belly fat) burns the fat there.”

Fat is lost across the body through an energy deficit; local exercise does not reduce local fat.

• Vispute SS, Smith JD, LeCheminant JD, Hurley KS. The effect of abdominal exercise on abdominal fat. J Strength Cond Res. 2011;25(9):2559-2564. doi:10.1519/JSC.0b013e3181fb4a46

“Light weights and high reps "tone", heavy weights "bulk".”

"Toning" is building muscle and losing fat; both light and heavy loads build muscle when sets are hard, and bulk depends on surplus and years of training.

The evidence: Load and rep range

• Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training: a systematic review and meta-analysis. J Strength Cond Res. 2017;31(12):3508-3523. doi:10.1519/JSC.0000000000002200
• Lopez P, Radaelli R, Taaffe DR, et al. Resistance training load effects on muscle hypertrophy and strength gain: systematic review and network meta-analysis. Med Sci Sports Exerc. 2021;53(6):1206-1216. doi:10.1249/MSS.0000000000002585

“You must constantly change exercises to "confuse" or "shock" the muscle.”

Progress comes from progressive overload on consistent exercises; random rotation makes progress harder to track and achieve.

The evidence: Exercise variation

• Kassiano W, Nunes JP, Costa B, et al. Does varying resistance exercises promote superior muscle hypertrophy and strength gains? A systematic review. J Strength Cond Res. 2022;36(6):1753-1762. doi:10.1519/JSC.0000000000004258
• American College of Sports Medicine. Position stand: progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708. doi:10.1249/MSS.0b013e3181915670

“No pain, no gain: every set should go to total failure.”

Stopping about 0–3 reps short gives nearly all the growth with less fatigue; pain is a signal, not a goal.

The evidence: Effort and proximity to failure

• Refalo MC, Helms ER, Trexler ET, Hamilton DL, Fyfe JJ. Influence of resistance training proximity-to-failure on skeletal muscle hypertrophy: a systematic review with meta-analysis. Sports Med. 2023;53(3):649-665. doi:10.1007/s40279-022-01784-y

“"Starvation mode" stops fat loss when you eat too little.”

Metabolic adaptation is real but modest; it slows loss, it does not stop it in a true deficit. Stalls are usually logging gaps or water.

The evidence: Weight change is not linear

• Trexler ET, Smith-Ryan AE, Norton LE. Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr. 2014;11:7. doi:10.1186/1550-2783-11-7
• Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837. doi:10.1016/S0140-6736(11)60812-X

“Carbs (especially at night) make you fat.”

Fat gain follows the total energy balance; when calories and protein are equal, carbohydrate amount and timing do not change fat loss.

The evidence: Carbohydrate

• Hall KD, Guo J. Obesity energetics: body weight regulation and the effects of diet composition. Gastroenterology. 2017;152(7):1718-1727. doi:10.1053/j.gastro.2017.01.052

“Eating 6 small meals "stokes the metabolism".”

Meal frequency does not change fat loss when daily calories are equal.

The evidence: Meal frequency

• Schoenfeld BJ, Aragon AA, Krieger JW. Effects of meal frequency on weight loss and body composition: a meta-analysis. Nutr Rev. 2015;73(2):69-82. doi:10.1093/nutrit/nuu017

“Fasted cardio burns more fat.”

It burns more fat during the session but not more fat over the day or the diet when calories are matched.

The evidence: Fasted cardio

• Schoenfeld BJ, Aragon AA, Wilborn CD, et al. Body composition changes associated with fasted versus non-fasted aerobic exercise. J Int Soc Sports Nutr. 2014;11:54. doi:10.1186/s12970-014-0054-7

“Detoxes, cleanses or fat-burner supplements speed up fat loss.”

The liver and kidneys clear waste; no detox product or fat burner has good evidence for meaningful fat loss.

The evidence: Other supplements

• Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. doi:10.1186/s12970-018-0242-y

“Sweating more means burning more fat.”

Sweat is water lost for cooling; it comes back when you drink.

The evidence: Hydration

• Sawka MN, Burke LM, Eichner ER, et al. American College of Sports Medicine position stand: exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377-390. doi:10.1249/mss.0b013e31802ca597

“Stretching before training prevents injuries.”

Strength and balance training reduce injuries; static stretching has not been shown to.

The evidence: Injury prevention

• Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. Br J Sports Med. 2014;48(11):871-877. doi:10.1136/bjsports-2013-092538