Research Chosen by Tim, Head Strength Coach

The research behind the program

Tim reads the research so the program does not have to guess. This is what it is built on, in plain words: what each study found, who was in it, how much weight it can bear, and what we do with it.

Read this first

None of these studies is about GLP-1 medication. They are about the situation a GLP-1 puts you in: eating less and losing weight, often after 40. Most are small, and many measure muscle-building over a few hours rather than muscle gained over months, which is a clue, not a result. Each card says who was studied and how strong the finding is. Nothing here is medical advice; questions about your medication, your dose or your kidneys belong with your doctor.

Jump to: Eating less · After 40 · A small appetite · The training

Eating less

A small lab study

Eating less turns down muscle-building, even with good protein.

After 10 days of eating about 20% less than they needed, muscle-building in active adults was about 19% lower than when they ate enough, even though protein was held at 1.5 g per kg of body weight the whole time.

Who: 12 physically active adults (8 men, 4 women), 10 days at each intake.
Keep in mind: Short, small and well controlled. A GLP-1 deficit is usually larger and lasts months.
In the program: Why the plan pairs a protein number with lifting from the first week: in a deficit, protein alone is not enough.

Pasiakos SM, Vislocky LM, Carbone JW, et al. Acute energy deprivation affects skeletal muscle protein synthesis and associated intracellular signaling proteins in physically active adults. J Nutr 2010;140:745–751. Read the paper →

A review of many studies

Protein plus lifting is what keeps muscle while you lose weight.

Across the studies reviewed, more protein together with resistance training preserved muscle during weight loss, and sometimes added some. When weight loss was moderate, 1.6 g of protein per kg a day preserved lean mass. When the deficit was large and the weight came off fast, protein could not fully stop the loss.

Who: A review of studies in dieting adults and athletes.
Keep in mind: Not about GLP-1s, where the weight often comes off fast. That is the case the review calls hardest.
In the program: Your daily protein target is 1.6 g per kg of body weight, capped at 160 g. The program is lifting, not cardio, because lifting is the other half.

Phillips SM. A brief review of critical processes in exercise-induced muscular hypertrophy. Sports Med 2014;44(Suppl 1):S71–S77. Read the paper →

An expert position statement

1.4 to 2.0 g of protein per kg is safe for active, healthy people.

For people who exercise, 1.4–2.0 g of protein per kg a day is safe and may improve the results of training. At those amounts, as part of a balanced diet, it was not harmful to the kidneys or bones of healthy, active people.

Who: The International Society of Sports Nutrition, reviewing the research to 2007.
Keep in mind: Healthy people only. With reduced kidney function, a protein target is a conversation with your doctor.
In the program: The 1.6 g/kg target sits inside this range, and the 160 g cap keeps heavier members from a number worked out from total weight.

Campbell B, Kreider RB, Ziegenfuss T, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr 2007;4:8. Read the paper →

After 40

A small lab study

Older muscle responds to lifting and protein more slowly.

After a leg workout and 20 g of essential amino acids, muscle-building rose within 1–3 hours in the younger men and only at 3–6 hours in the older men.

Who: 7 younger and 6 older men, ages 24 to 77, a single workout.
Keep in mind: One session, measured over hours. It shows a delay, not that older muscle cannot grow.
In the program: Why protein is spread through the day rather than squeezed into a window after training.

Drummond MJ, Dreyer HC, Pennings B, et al. Skeletal muscle protein anabolic response to resistance exercise and essential amino acids is delayed with aging. J Appl Physiol 2008;104:1452–1461. Read the paper →

A small lab study

After 50, a bigger serving of protein does more.

In middle-aged men, 170 g (6 oz) of beef, about 36 g of protein, raised muscle-building more than the smaller servings, at rest and even more after a workout.

Who: 35 men averaging 59 years old, one meal of 0, 57, 113 or 170 g of beef.
Keep in mind: One meal, men only, measured over hours.
In the program: Why your protein number is a real number, not "some protein": about 30–40 g at the meals you can manage.

Robinson MJ, Burd NA, Breen L, et al. Dose-dependent responses of myofibrillar protein synthesis with beef ingestion are enhanced with resistance exercise in middle-aged men. Appl Physiol Nutr Metab 2013;38(2):120–125. Read the paper →

A very small study

It is not too late at 70.

Men averaging 74 years old lifted three times a week for 12 weeks. Their one-rep max went up by about 52%, and the muscle fibres themselves changed.

Who: 7 healthy men averaging 74, knee-extension training at 80% of their max.
Keep in mind: Seven people and one exercise. Encouraging, not a promise.
In the program: The program is the same at 45 or 70: three short sessions, with the load going up as you get stronger.

Williamson DL, Godard MP, Porter DA, Costill DL, Trappe SW. Progressive resistance training reduces myosin heavy chain coexpression in single muscle fibers from older men. J Appl Physiol 2000;88:627–633. Read the paper →

A small appetite

An expert opinion paper

There is no hard limit of 20–30 g of protein per meal.

The idea that anything over 20–30 g at a meal is wasted looks only at muscle-building. Counting muscle breakdown too, the net gain kept rising with more protein, with no practical upper limit at a meal.

Who: An opinion paper by two protein researchers, re-reading the evidence.
Keep in mind: An argument from existing studies, not a new experiment.
In the program: If you can only face one real meal, make it protein-heavy. It is not wasted.

Deutz NEP, Wolfe RR. Is there a maximal anabolic response to protein intake with a meal?. Clin Nutr 2013;32(2):309–313. Read the paper →

A randomised trial

Most of the day’s protein in one meal can still build lean mass.

Older patients who ate about 72% of their day’s protein at lunch gained lean mass over 6 weeks, while those who spread the same protein over four meals did not. Grip strength did not differ.

Who: 66 malnourished or at-risk patients in a hospital rehabilitation unit, randomised.
Keep in mind: A very different group: older, in hospital, under-nourished. It shows one big protein meal can work, not that it beats spreading it out for you.
In the program: Hitting the daily total matters most. Spread it if you can; if you cannot, put it where your appetite is.

Bouillanne O, Curis E, Hamon-Vilcot B, et al. Impact of protein pulse feeding on lean mass in malnourished and at-risk hospitalized elderly patients: a randomized controlled trial. Clin Nutr 2013;32(2):186–192. Read the paper →

A review of many studies

Protein before bed is used overnight.

Protein eaten before sleep is digested and used to build muscle overnight; about 40 g gave a clear effect. In a 12-week study, young men who lifted and had 27.5 g of protein before bed gained more muscle and strength than men who had a placebo.

Who: A review by the research group that ran most of these studies.
Keep in mind: The protein was compared with nothing, not with the same protein earlier in the day, so the benefit may be the extra protein, not the timing.
In the program: If you are short of your protein number, an evening protein snack is a reasonable place to find it. Not a rule.

Trommelen J, van Loon LJC. Pre-sleep protein ingestion to improve the skeletal muscle adaptive response to exercise training. Nutrients 2016;8(12):763. Read the paper →

The training

A small lab study

Lighter weights work, if you take the set close to failure.

Sets at 30% of max taken to failure raised muscle-building as much as sets at 90% of max taken to failure, and it stayed raised longer. Light sets that stopped well short of failure did less.

Who: 15 young men, one leg workout, measured over 24 hours.
Keep in mind: Young men and one session. Effort near the end of the set is the point, not the exact weight.
In the program: Why the program says "heavy-ish" and leaves a few reps in the tank: effort matters more than the number on the dumbbell, which is good news for joints.

Burd NA, West DWD, Staples AW, et al. Low-load high volume resistance exercise stimulates muscle protein synthesis more than high-load low volume resistance exercise in young men. PLoS ONE 2010;5(8):e12033. Read the paper →

A review of many studies

Beginners respond the most.

In people new to lifting, muscle-building after a workout is larger and lasts longer than in trained people; the response gets smaller as training goes on. The review also warns that these short-term measurements do not reliably predict how much muscle someone gains over months.

Who: A review of the studies measuring this across a training program.
Keep in mind: The warning in it applies to most of this page: hours of muscle-building are a clue, not a result.
In the program: Why the first weeks matter so much, and why progress is checked with real measurements in the app, not promised.

Damas F, Phillips S, Vechin FC, Ugrinowitsch C. A review of resistance training-induced changes in skeletal muscle protein synthesis and their contribution to hypertrophy. Sports Med 2015;45(6):801–807. Read the paper →

A small lab study

Lift first, walk after.

Doing cardio and lifting back to back changed how the muscle responded depending on the order. When cycling came first, a muscle-growth signal (IGF-I) dropped by about 42%.

Who: 8 young, fit men, each doing both orders.
Keep in mind: Gene signals measured over 3 hours, not muscle gained. A small nudge, not a rule to stress over.
In the program: When a session includes a walk, it comes after the lifting.

Coffey VG, Pilegaard H, Garnham AP, O’Brien BJ, Hawley JA. Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle. J Appl Physiol 2009;106:1187–1197. Read the paper →

More in plain words on the Greatest Workout blog. Links go to each paper's publisher page; some are free to read, some are not.