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 three 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 if ice baths and massage help you recover your strength faster, if the 5:2 diet is superior to regular dieting for fat loss, and if walking backward boosts your athletic performance (seriously). 

 

Ice baths and massage ease muscle aches but don’t help you recover your strength faster.

Source: “Cold-Water Immersion and Sports Massage Can Improve Pain Sensation but Not Functionality in Athletes with Delayed Onset Muscle Soreness” published on December 5, 2022 in Healthcare (Basel, Switzerland).

We weightlifters are always looking for ways to improve our recovery.

That’s because the faster we recuperate, the sooner we can train hard again and gain muscle and strength.

And while plenty of recovery options are available, two that have become particularly popular of late are ice baths and massage. 

This is largely because a 2018 meta-analysis found these recovery strategies were among the best for reducing soreness and inflammatory blood markers and making you feel subjectively better after training. 

This all good and well but there’s just one snag: Just because a recovery method helps you feel better doesn’t mean it makes you recoup your strength faster or adapt better to your training. And if a recovery technique doesn’t allow you to train harder sooner, it’s probably overrated.

Are ice baths and massage only good for helping soothe your sore muscles? Or do they help you regain your strength faster, too?

That’s what scientists at the University of Patras sought to find out with this study

The researchers split 60 amateur athletes into 4 groups. Each group performed 5 sets of 20 drop jumps from a 2-foot step, then did 1 of 4 recovery interventions:

  1. Cold Water Immersion: Athletes sat in iced water (~10°C) up to their waists for 10 minutes.
  2. Massage: Athletes received a 20-minute massage (10 minutes on each quad).
  3. Cold Water Immersion+Massage: Athletes received a 20-minute massage followed by 10 minutes of cold water immersion as described above. 
  4. Control: Athletes received no recovery intervention.

The results showed that the athletes were significantly weaker the day after the jumping workout and that all the recovery techniques improved muscle soreness faster than doing nothing, but none helped the athletes recover their strength more quickly (they all took ~4 days to get back to their pre-exercise strength).

In other words, ice baths and massage make you feel better after exercise but don’t help your strength return sooner—and that means they have less utility than many believe.

It’s also worth noting that there’s also some evidence ice baths may interfere with some of the adaptations to training and muscle growth (likely by reducing inflammation),

That isn’t to say ice baths and massage are useless; they may help you shake off soreness when you’re feeling particularly beaten up.

However, they probably aren’t as effective as doing the basics correctly, including following a well-designed training program that has you doing the right amount of volume, eating an adequate number of calories and enough protein, supplementing intelligently, and getting plenty of sleep.

If you want a training program, diet plan, and supplement regimen that covers most of these bases, check out my fitness books for men and women, Bigger Leaner Stronger and Thinner Leaner Stronger

(If you aren’t sure if Bigger Leaner Stronger or Thinner Leaner Stronger is right for you or if another strength training program might be a better fit for your circumstances and goals, take 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.)

TL;DR: Ice baths and massage can reduce soreness and markers of muscle damage after training, but they don’t help you recoup your strength faster.

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The 5:2 diet won’t help you lose fat faster than regular dieting.

Source: “Intermittent fasting and protein pacing are superior to caloric restriction for weight and visceral fat loss” published on December 27, 2022 in Obesity (Silver Spring).

The 5:2 diet involves greatly restricting your calorie intake 2 days per week and eating normally on the remaining 5 days.

Some people believe this special style of nutrient timing will help them lose weight and optimize their metabolic health.

Even weightlifters who buy into this are reluctant to give it a go, though, because it generally involves eating very little protein two days per week, which, theoretically, isn’t ideal for muscle building. 

With this in mind, scientists at Skidmore College conducted a study to determine whether you can nullify the downsides of eating a low-protein diet 2 days per week by being very particular about how you consume protein on the other 5 days.

The researchers split 39 overweight and inactive people into two groups.

The first group followed a regular calorie-controlled diet, eating 1,200-to-1,500 calories per day, with 50-to-60% of calories from carbs, <35% from fat, and the rest from protein. 

The second group followed a diet that involved eating regularly 5-to-6 days per week (feeding days) and fasting 1-to-2 days per week (fasting days).

On feeding days, the dieters got 35% of their calories from protein, 35% from carbs, and 30% from fat. They also followed a “protein pacing” strategy, which involved eating 20-to-40 grams of protein in 4-to-5 meals spread evenly throughout the day.

On fasting days, they ate 400-to-500 calories and very little protein.

After 8 weeks, there were some surprising changes in the dieters’ body compositions.

The fasting group reduced their body weight (~18 lb vs.~11 lb), body fat (~13 lb vs. ~8 lb), body fat percentage (-3.4% vs. 1.8%), abdominal fat (~2 lb vs. ~1 lb), and visceral fat (~1.3 lb vs. ~0.7 lb) significantly more than the regular diet group. The fasters also lost a little more muscle than the regular dieters, though the difference wasn’t statistically significant.

Even more surprising was that these changes occurred despite both groups ostensibly doing similar amounts of physical activity and eating the same number of calories per week. The only notable difference between the diets was that the fasting group ate significantly more protein on average (125 g per day vs. 72 g per day).

Many fasting tub-thumpers took these results as proof that fasting is superior to conventional dieting for fat loss because both groups ate and exercised the same amount yet the fasters lost more fat.

Yeah . . . not so fast.

First, the fasting group ate almost twice as much protein as the regular dieters. This is significant because protein helps you retain muscle and has a higher thermic effect than carbs and fat, which could increase overall energy expenditure and, thus, fat loss. 

Second, the researchers measured physical activity using accelerometers for just 6 days during the study. The problems with this are that accelerometers aren’t particularly accurate, and the dieters’ activity on the 6 days they measured physical activity may not have indicated how active they were over the entire 8 weeks.

Third, the dieters prepared many of their own meals, self-reported what they ate, and only tracked their diets for 6 days, which means it’s likely they didn’t track accurately.

Fourth, one of the participants in the fasting group lost significantly more weight than everyone else (~55 lb), which greatly impacted the average weight loss numbers. If you remove this person’s data from the results, you largely wipe out the difference.

Fifth, a supplement company funded the research and provided the fasters with several of their own supplements. While we can’t say for sure that financial interest colored the results, it seems convenient that those who used the supplements had exceptional results, while those who didn’t lost a lot less weight.

(Another suspicious detail was that the researchers measured the dieters’ body composition changes using DXA but decided against reporting the data in the write-up. Again, it would be unfair to assume that the study’s benefactor pulled this data because it didn’t paint their supplements in a perfect light, but it’s possible.)

And finally, most other research shows that when calorie intake is the same, fasting is no more effective than regular dieting for weight loss. 

Regardless of what many media outlets and diet “gurus” have claimed since this study’s publication, I don’t think we should rethink our stance on fasting or the 5:2 diet specifically.

Fasting may help you lose weight by making it easier to consume fewer calories. It’s likely no more effective than regular dieting, though, so if you find forgoing food for long periods unpleasant, don’t feel like you have to persist. A more traditional meal schedule is probably a better fit for you.

(And if you’d like specific advice about what diet to follow to reach your fitness 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: Fasting can help some people lose weight but it probably isn’t more effective than regular calorie-controlled dieting.

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Backward walking may boost athletic performance (yes, seriously).

Source: “Retrograde Training: Effects on Lower Body Strength and Power” published on December 1, 2022 in International Journal of Sports Medicine.

Walking backward is experiencing a boom.

This is primarily thanks to Ben Patrick (a.k.a, Knees Over Toes Guy), who’s spent the last few years banging the drum for backward walking (among other techniques) as a way for athletes to maximize joint longevity, prevent injuries, strengthen the quads, and improve balance.

And while there are mountains of anecdotal evidence that what Mr. Patrick preaches produces good results, scientific evidence is lacking.

The only research we have on backward walking shows that it can improve balance and gait in the elderly and infirm, but it’s probably not sensible to extrapolate these findings to healthy people who regularly exercise.

That’s because inactive people generally make big improvements when they start doing physical activity of any kind. For those of us who lift weights, do cardio, play sports, practice martial arts, and are generally active, though, simple exercises that greatly benefit sedentary, elderly, or disabled people rarely produce similar results. 

But could they in this case?

That’s why researchers at Avera McKennan Hospital and University Health Center conducted this study investigating the effects of backward walking (which they call “retrograde training”) on 37 healthy people who regularly lift weights and do cardiovascular exercise. 

The researchers split the people into a control group and a backward-walking group.

The control group continued to train as normal for 6 weeks. The backward-walking group replaced all of their regular lower-body training with a 6-week backward walking program that involved 3 backward-walking workouts weekly.

In each backward-walking workout, the walkers did a series of 10 and 30 second intervals of backward walking on a treadmill interspersed with at least 2 minutes of rest. Throughout the study, the researchers increased the speed and incline of the intervals to make the workouts more challenging.

The results showed that the backward-walking group increased their jump height by ~4%, jump length by ~7%, and leg press strength by ~10-to-11%. In contrast, the control group saw no improvement in these metrics.  

As impressive as these results are, it’s still probably too early to recommend backward walking to all weightlifters. There are too many hanging questions for that.

For example, in this study, the participants stopped training their lower body while performing their backward-walking workouts. As such, we don’t know whether you’d get the same benefit from backward walking if you also trained your legs

We also don’t know whether adding backward walking to your program would impact your recovery and hamper your performance in your lower-body weightlifting workouts. If it did, you may have to limit your weightlifting volume to accommodate backward walking.

Furthermore, it’s unclear whether backward walking helps you build muscle. If not, people with purely aesthetic goals would have little use for it. 

Finally, this study only investigated interval-style backward walking. It also used inclines that few commercial gym treadmills go up to. This leaves two unanswered questions: Would you get the same benefits from lower-intensity, longer-duration backward walking? And would you see similar results if you did your backward-walking workouts at a lower incline?

With so many holes in our knowledge, it’s too early to get excited about backward walking. That said, the early signs are promising, and I won’t be at all surprised if future research is positive.

TL;DR: Interval-style backward walking on an incline may boost jump height and distance and leg strength.

+ Scientific References