| Hey there, Can “glute activation” exercises help you get a bigger booty faster? How does the 5:2 diet affect body composition? The answers are in this email, according to science! (Oh, and if you want to peruse the research I’m citing, you can find links to everything here: https://legionathletics.com/research-roundup-3/?he=&el=email) Glute “activation exercises” might improve muscle activation. These days, you can’t scroll more than a swipe or two without seeing someone touting the benefits of simple warm-up exercises that purportedly help a particular muscle “fire” harder during your workout. I’ve been skeptical of this theory for a couple reasons: - Why would doing easy body weight exercises before more challenging ones improve muscle activation in the latter?
- Even if it did, wouldn’t simply using heavier weights accomplish this better, and wouldn’t that extra 10-to-20 minutes of futzing around with an exercise band be better spent just doing more working sets of regular exercises?
A study conducted by scientists at the University of Southern California doesn’t definitively answer these questions but does offer some insight. In this study, the researchers hooked 12 men and women up to an EMG (which measures the electrical activity inside a muscle) and measured how active their glutes were during 3 sets of 3 reps of bodyweight squats and split squats. The participants then went home and performed “glute activation training” twice per day for a week before returning to the lab to repeat the workout. The glute activation training consisted of three exercises: Side-lying clamshells, side-lying hip abduction (lifting your leg up), and quadruped fire hydrants. The participants completed three one-minute isometric holds for each exercise and used resistance bands to make the exercises harder as necessary. After a week of this, the researchers found that participants’ glutes were 57% more active during the bodyweight squat and 53% more active during the split squat. Big numbers, to be sure, but I’m still skeptical about the practical value of such a finding. First, EMG only measures the electrical activity of a muscle, not growth. And while muscle activation is necessary for building muscle–no activation always means no growth–it isn’t the best proxy for gauging gains. For instance, the barbell hip thrust often produces more glute activation than the barbell squat, but due to a variety of factors (shorter range of motion and less stretching of the muscle fibers, mainly), research shows the squat is a better exercise for building your booty. Second, it’s possible any benefits from the glute activation exercises performed would disappear as you get stronger on exercises like the barbell squat, which will always produce high levels of glute activation. In other words, while activation exercises might help newbies better stimulate their glutes in their lower-body training, the effect might disappear as they get stronger. A reasonable counterargument, however, is that such activation exercises are simple and stressless, so there’s no downside in trying them out. TL;DR: Regularly performing easy exercises that target the glutes, such as side-lying clamshells, side-lying hip abduction, and quadruped fire hydrants, may increase muscle activation in your hard training, which could result in more muscle growth. The 5:2 diet isn’t ideal for preserving muscle while cutting. If you consistently maintain a calorie deficit, you’ll lose weight regardless of, well, anything else, but nobody wants to just lose weight. We want to lose fat and not muscle, i.e. improve our body composition, and with that crucial caveat, we have to consider more than just calories. And while most everyone agrees that protein intake must be regarded, there’s a lot of debate about meal timing, and fasting in particular is usually on the front burner. Does it help or hurt fat loss? What about muscle retention? A recent study published in the European Journal of Nutrition investigated these questions using the 5:2 intermittent fasting diet, which calls for 5 days of normal eating and 2 days of severe caloric restriction. The researchers took 17 untrained 18-to-45-year-old men and women and had them all maintain a 20% calorie deficit and eat 0.6 grams of protein per pound of body weight per day on average. (This amount of protein is less than ideal when dieting, but still enough to significantly reduce muscle loss and appetite). Although everyone ate the same amount of calories and protein, half of the participants followed a traditional, continuous diet, eating the same number of calories every day. The other half followed a 5:2 diet plan, eating at maintenance on 5 days per week and in a 70% deficit (just 30% of their TDEE) on 2 days per week. Everyone tested their bench and leg press strength at the beginning and end of the study and did three full-body strength training workouts per week. After following this regimen for 12 weeks, both groups gained about the same amount of strength, which isn’t surprising since all the participants were enjoying those celestial newbie gains. The body composition results were more interesting, though. According to the DXA results, both groups lost about the same amount of weight and retained about the same amount of muscle. However, results from the ultrasound and CT scans showed that the group that dieted continuously experienced larger increases in several measures of muscle size. While most of these measurements failed to reach statistical significance, they probably would have if the study had lasted longer than 12 weeks. And this suggests that continuous dieting may be better for maintaining muscle while cutting (or gaining muscle while losing fat if you’re new to weightlifting) than the 5:2 diet. (And if reading this has got you wondering what kind of diet is right for your circumstances and goals, then take the Legion Diet Quiz! In less than a minute, you’ll know exactly what diet is best for you.) TL;DR: If you’re cutting, you’ll probably lose just as much fat and retain more muscle with a continuous calorie deficit instead of following the 5:2 diet. When it comes to fat loss, it doesn't matter what time of day you do cardio. Nutrient timing is a bit like alchemy. People have been tinkering with it for years, it never lives up to the hype, and the general consensus among knowledgeable people who’ve studied the topic closely is “it doesn’t matter, LOL.” All the same, new research occasionally crops up that makes you take another look. For example, research published by German scientists in 2020 showed that our circadian rhythm may cause our body to burn slightly more calories digesting food we eat in the morning than in the evening. This caught the eye of some other scientists at the University of Colorado, who wondered, do we burn more calories exercising in the morning than in the evening? To answer this question, the scientists divided 33 overweight or obese 18-to-56-year old men and women into a morning cardio group (6-to-10 a.m.) and an evening cardio group (3-to-7 p.m.). The participants did 4 cardio workouts per week during their prescribed time windows, and the workouts got more difficult as the 15-week study progressed. At first blush the results seemed to show a landslide win for morning cardio. Specifically, the folks who did cardio in the morning burned 132 calories more per day on average than the folks who did cardio in the evening. Napkin math says: 132 (extra calories burned) x 7 (days per week) ÷ 3,500 (-ish calories in a pound of fat) = an extra quarter pound of fat loss per week Just from doing cardio in the morning instead of evening! Before you move your alarm back, though, let's talk about the details. For one thing, the evening cardio group actually lost more weight and fat than the morning cardio group, but this was because the morning group also ate about 120 calories more per day on average (essentially, they “ate back” the calories they burned during their workouts). What if they didn’t accidentally eat more, though? Would the morning cardio group have been the clear winner? Not necessarily. The difference in the total daily energy expenditure between the two groups wasn’t in the energy burned during their workouts but in the energy burned in non-exercise activities. Specifically, while the morning cardio crew saw a ~60-calorie decrease in daily non-exercise activity thermogenesis (or NEAT, as “calories burned through random non-exercise activity” is technically called), the evening crowd saw a ~200-calorie decrease. Hence, the morning exercisers were burning more calories on average every day than the evening cohort. And why? Did the sunup cardio session somehow stimulate more daily activity? The researchers weren’t sure. Maybe. Maybe not. Maybe the difference observed was just a statistical hiccup or experimental artifact. And even if exercising in the morning did somehow encourage slightly more non-exercise activity throughout the rest of the day, that’s mildly interesting at best to those of us who are more scrupulous than the average person about how much we move and eat. So, until further evidence emerges, my position on cardio timing remains the same: it probably doesn’t matter when you do it. TL;DR: When you do cardio probably doesn’t impact energy expenditure to a meaningful degree. Do it whenever works best for you. Alright frando, that’s it for this week. Whatcha think about these studies? Any feedback you’d like to share? Hit reply and let me know! Oh and if you’re enjoying this series, watch out for the next one, where I’ll cover new science on the “interference effect,” how much muscle you can gain while losing fat, and more. Mike | 
