It’s estimated that there are over 2+ million scientific papers published each year, and this firehose only seems to intensify.

Even if you narrow your focus to fitness research, it would take several lifetimes to unravel the hairball of studies on nutrition, training, supplementation, and related fields.

This is why my team and I spend thousands of hours each year dissecting and describing scientific studies in articles, podcasts, and books and using the results to formulate our 100% all-natural sports supplements and inform our coaching services. 

And while the principles of proper eating and exercising are simple and somewhat immutable, reviewing new research can reinforce or reshape how we eat, train, and live for the better. 

Thus, each week, I’m going to share five scientific studies on diet, exercise, supplementation, mindset, and lifestyle that will help you gain muscle and strength, lose fat, perform and feel better, live longer, and get and stay healthier. 

This week, you’ll learn how to train to gain muscle and strength in just 30 minutes per week, how foam rolling affects recovery, how well wearable activity trackers measure calorie burning, and more. 

You can gain muscle and strength training just 30 minutes per week.

Source: “No Time to Lift? Designing Time-Efficient Training Programs for Strength and Hypertrophy: A Narrative Review” published on June 14, 2021, in Sports medicine (Auckland, N.Z.).

By far the number one excuse for not exercising is “I don’t have time.” Unfortunately for procrastinators everywhere, researchers at Norwegian University of Science and Technology decided to torpedo this idea with some science.

Specifically, they performed a narrative review (the researchers compiled evidence around a topic and shared their opinions about what it means) to identify the most time-efficient way to train.

Based on their reading of the data, here’s what they recommend:

  • Volume and frequency: Do at least one workout per week with a minimum of four sets per major muscle group. To maintain rather than gain muscle, it’s sufficient to do three sets per major muscle group per week.
  • Intensity: Do most of your sets in the 6-to-12 rep range (also what I recommend in Bigger Leaner Stronger and Thinner Leaner Stronger)
  • Exercise type: Prioritize compound barbell exercises that train your body bilaterally (both sides at a time). No surprises here.
  • Exercise selection: Do at least one pushing exercise (e.g. bench press), one upper-body pulling exercise (e.g. pull-up), and one leg pressing exercise (e.g. squat), each week. Push pull legs, basically.
  • Rest intervals: If you’ve been training for less than 12 months, rest one-to-two minutes between sets, and if you’ve been training for longer, rest at least two minutes. (My advice would be to rest as long as you need to feel ready for the next set, but that’ll work out to about what the researchers recommended for most people).
  • Advanced training methods: Incorporate supersets, drop sets, and rest-pause sets into your training where possible and practical.
  • Warming up: Do exercise-specific warm-ups only. (Don’t do long, complicated warm ups with exercise bands, plyometrics, and other faff). 
  • Stretching: Don’t spend time stretching unless you want to improve your flexibility.

Basically, they recommend you stick to traditional strength training fundamentals except with a slightly lower frequency and volume than what you might use if you were trying to maximize muscle and strength gain. My only quibble would be that I think drop sets probably aren’t the best use of time and rest-pause sets can be difficult to do with compound exercises, but that’s splitting hairs.

The key takeaway is that you just don’t need that much time to get fitter and stronger, and even less to stay fit and strong.

Of course, following these recommendations won’t help you maximize muscle and strength gain. For that, you’ll need to do more workouts, exercises, sets, and reps each week.

If you’d like specific advice about which training program you should follow to reach your health and fitness goals as quickly as possible, take the Legion Strength Training Quiz, and in less than a minute, you’ll know the perfect strength training program for you. Click here to check it out.

But if you only have 30 minutes or less to dedicate to exercise each week, you can use these findings to create a bare-bones approach to training that’ll still help you get fitter, stronger, and healthier with a single weekly workout. Here’s an example:

Tip: To make it even more time-efficient, you could alternate between sets of the bench press and pull-up, resting one minute between each set.

TL;DR: You can gain muscle and strength with just one 30-minute strength training workout per week (and maintain it with even less). 

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Whey protein won’t help you sleep better.

Source: “Evening Whey Protein Intake, Rich in Tryptophan, and Sleep in Elite Male Australian Rules Football Players on Training and Nontraining Days” published on December 7, 2021 in International Journal of Sport Nutrition and Exercise Metabolism.

Some supplement aficionados and “functional food” gurus believe that eating protein-rich foods before bed will help you sleep better because many of them contain an amino acid called tryptophan, a precursor to the “sleep hormones” melatonin and serotonin. 

The logic looks like this: protein -> tryptophan -> melatonin/serotonin = better, deeper, more restful sleep.

To test this idea, scientists at Deakin University had 15 elite male Australian Football League athletes consume a protein supplement or placebo 3 hours before bedtime in 4 different conditions:

  1. Whey protein supplement on a training day
  2. Placebo on a training day
  3. Whey protein supplement on a non-training day
  4. Placebo on a non-training day

(The whey protein supplements contained 55 grams of protein and 1 gram of tryptophan, and the calorie-matched and similar tasting placebo contained 6.5 grams of protein and 0.1 grams of tryptophan.)

For 5 days before each condition, the researchers tracked the athletes’ habitual diets using a smartphone application and sleep behaviors using a wrist activity monitor and a sleep diary. 

The researchers used the diet data they collected to provide the participants with a meal the night before each experimental condition and meals the day after each experimental condition that were typical of the athletes’ regular eating habits (this ensured the athletes didn’t skew the results by eating an unusually large or small amount of protein during the study).

During each condition, the researchers tracked just about every sleep-related measure you can think of, including  bedtime, wakeup time, time in bed, sleep onset latency (the time between going to bed and falling asleep), sleep duration, sleep efficiency (the percentage of time in bed spent sleeping), wake after sleep onset (the total time spent awake during the time in bed), and time moving (the time spent moving during sleep).

The results showed that consuming protein before bed made no difference in any of the variables the researchers measured, regardless of whether it was a training or non-training day.

While these results may seem blasé, they add to the growing body of evidence showing that pre-bed protein probably isn’t that important.

A common bodybuilding piety is that pre-bed protein prevents muscle breakdown during the night, but research shows this isn’t the case as long as your total daily protein intake is sufficient. You also don’t need to worry about consuming a slow-digesting protein like casein before bed, either, and can just focus on eating a sufficient amount of whatever type of protein you like throughout the day.

(And if you feel confused about how much of each macronutrient, how many calories, and which foods you should eat to reach your goals, take the Legion Diet Quiz, and in less than a minute, you’ll know exactly what diet is right for you. Click here to check it out.)

TL;DR: Don’t worry about eating pre-bed protein (whey, casein, or otherwise). It probably won’t help you sleep better or help prevent muscle loss.

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Partial range-of-motion deadlifts may help you get stronger.

Source: “The Efficacy of Partial Range of Motion Deadlift Training: A Pilot Study” published on February 22, 2022 in International Journal of Sports Science.

Among strength coaches, it’s axiomatic that exercises that use a full range of motion (ROM) are always better than exercises that use a partial ROM, but this study shows this might not be the case.

This study, conducted by scientists at Southwest Minnesota State University, split 19 college wrestlers with at least one year of weightlifting experience into two groups: a full-ROM deadlift group and a partial-ROM deadlift group.

Both groups followed the same 3-day training routine that included the bench press, hang clean, and back squat. The only difference was that the full-ROM group did two sets of three-to-five reps of full-ROM deadlifts, whereas the partial-ROM group did one set of three-to-five reps of full-ROM deadlifts and three sets of heavy partial-ROM deadlifts for a single rep. 

The partial-ROM deadlifts started with the bar resting on the safety pins of a squat rack one inch above knee height. In other words, one group just did normal deadlifts, and the other group split their sets between normal deadlifts and heavy rack pulls.

The researchers measured full- and partial-ROM deadlift one-rep max strength at the beginning and end of the six-week study, and found that neither group significantly increased their full-ROM deadlift one-rep max. However, despite not being statistically significant, the full-ROM group experienced a small decrease in one-rep max strength (-12 pounds) and the partial-ROM group experienced a small increase in one-rep max strength (+10 pounds).

The partial-ROM group also significantly increased their partial-ROM deadlift one-rep max (~100 pounds), while the full-ROM group didn’t increase their partial-ROM deadlift significantly (~26 pounds).

On the face of it, one might conclude that doing a mix of full- and partial-ROM training is better than full-ROM training for gaining strength, but that would be getting hasty, Master Meriadoc. After all, the only significant difference between the groups in this study was partial-ROM deadlift strength.

What this study does suggest, though, is that using partial-ROM exercises don’t just boost your ego—they may help you gain strength, too, especially if they help you train a part of a lift that you find difficult.

For example, if you struggle to lock out a deadlift, try the rack pull; if you grind through the last few inches of a bench or overhead press, use the pin press; and if you find it difficult to get “out of the hole” in the squat, do the pin squat (or pause squat). Partial-ROM exercises like these help you build strength where you’re weakest, which could help you lift more weight when you go back to full-ROM lifting. 

TL;DR: Incorporating some partial-range-of-motion exercises into your weightlifting routine may help you gain more strength than only using full-range-of-motion exercises (though they should be used sparingly and as-needed). 

Foam rolling doesn’t help you recover faster (though it may help you stay more agile).

Source: “The Influence of Foam Rolling on Recovery from Exercise-Induced Muscle Damage” published in September, 2019 in Journal of Strength and Conditioning Research.

Many people think foam rolling helps your muscles recover after training by squishing out all of the ooey-gooey metabolites and acids and stuff that accumulates and breaking up all of the adhesions and trigger points and . . . other bad things that hinder recovery . . . or something. 

As you can probably tell, I’m not sold on this idea, and this study backs up my skepticism. 

The researchers split 37 men who hadn’t foam rolled in 30 days into 2 groups: a foam-rolling group and a non-foam-rolling group. 

On the first day of the experiment, the researchers gathered baseline data by measuring the participants’ hip abduction range of motion (how far they could move their thigh out to the side, away from their body’s centerline), hamstring muscle length, agility, and muscle soreness in their quads, hamstrings, glutes, and calves.

After both groups warmed up, the foam-rolling group performed six foam rolling exercises targeting the quads, hamstrings, glutes, and calves using a high-density foam roller on both legs for two 60-second bouts each, and the non-foam-rolling group did nothing.

Both groups then completed a sprint workout consisting of forty 15-meter sprints (gee willikers that sucks), before the foam-rolling group performed the same foam rolling protocol as before, and the non-foam-rolling group again did nothing.

To finish the first day of the study, the researchers assessed the participants’ recovery using the same protocol that they used to gather baseline data, and then took the same measurements again every day over the next four days. The foam-rolling group also performed the same foam-rolling protocol before each of these visits.

And how much did mashing and mauling their legs with a foam roller improve recovery?

It didn’t. At all. 

The results showed that the participants in the foam-rolling group didn’t improve measures of muscle soreness, hamstring muscle length, hip abduction range of motion, or vertical jump performance more than those in the non-foam-rolling group. 

The one exception was that foam rolling seemed to help maintain agility slightly better than doing nothing. Of course, one has to wonder if you could get similar benefits from other interventions like doing some leg swings, a recovery workout or two, a few minutes of yoga, and so on, or if the benefits were really unique to foam rolling.

At any rate, if your main concern is recovering as fast as possible from your workouts, you can ditch the foam roller—getting a massage, going for a gentle bike ride or walk, and taking supplements such as creatine and protein are going to offer more bounce for the ounce. 

TL;DR: Foam rolling after a workout doesn’t help you recover from exercise, but it might help you stay a little more agile (though even then, the jury is still out).

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Activity trackers aren’t a good way to measure your calorie burn.

Source: “Wrist-worn devices for the measurement of heart rate and energy expenditure: A validation study for the Apple Watch 6, Polar Vantage V and Fitbit Sense” published on January 21, 2022 in European Journal of Sports Science.

One of the main draws of activity trackers like the Apple Watch, Whoop, and Fitbit is that they claim to accurately measure the calories you burn throughout the day—and from exercise in particular.

Are they accurate, though?  

Scientists at the University of Quebec in Montreal attempted to answer this question by testing the accuracy of three popular “wearables:” the Apple Watch 6, the Polar Vantage V, and the Fitbit Sense. 

The researchers had 30 men and 30 women sit, walk, run, lift weights, and cycle for 10 minutes while they wore each of these devices. 

To calibrate the accuracy of these activity trackers, the researchers also had the participants wear medical devices proven to accurately measure heart rate and energy expenditure.

Long story short, the wearables were about as accurate as Al Gore’s climate change predictions.

Not only did they wildly miss the mark, they were also inconsistent and unreliable. 

This distinction between consistency and accuracy is an important one. If, say, the Fitbit consistently underpredicted your calorie burn by 100 calories from every workout, that could still help you establish a baseline from which you could modify your eating and exercise habits, even though the number isn’t perfectly accurate. Basically, inaccurate data can still be useful if it’s consistently inaccurate. 

Instead, these devices were inconsistent and inaccurate, over- and underpredicting calories in haphazard fashion.

One exception is that the Apple Watch was fairly accurate at measuring heart rate, which is useful if you use this to track the intensity of your cardio workouts. It still didn’t accurately or reliably measure calorie burn, though. 

This study isn’t the first to show that commercially available activity trackers don’t accurately measure calorie burn. While their accuracy will probably improve over time, this is something of a moot point, since a much better way to control your weight is to track your “calories in” and adjust based on how your body responds, and not trying to track “calories out.” 

If you’d like to calculate how many calories you should eat to lose fat, build muscle, or maintain your weight, take the Legion Diet Quiz, and it’ll tell you exactly how many calories and grams of protein, carbs, and fat you should be eating.

TL;DR: Don’t trust the calorie burn estimates you get from activity trackers like the Fitbit, Apple Watch, or Polar Vantage—they aren’t accurate or consistent.

+ Scientific References