Exercise scientist answers the web’s 6 most searched questions

Categories: Videos & podcasts


00:00 1. Which exercises help with weight loss?

01:29 2. How to get bigger arms?

03:44 3. What are the best high intensity interval training workouts?

05:20 4. How many times a week should I exercise?

08:13 5. How to build muscle?

08:43 6. What time of day should I exercise?

10:13 Conclusion


Question one: Which exercises help with weight loss?

Well, all exercises help with weight loss to the extent that they help put you in energy deficit. Weight loss, or rather fat loss, that should be the goal, not losing muscle, is all about creating energy deficit and being there for a prolonged period of time. If you are in energy deficit, the body burns more calories than it consumes and it is forced to make up the difference by burning some of its own tissues. If you are doing strength training or some type of physical activity that helps you maintain muscle mass, the end result is that your body should be burning fat, not muscle, and that is what we want. Exercises are not that different in how much energy they burn. Different types of exercise can burn different amounts of energy, but by and large, it’s just a matter of how effortful you’re training, not so much exactly what type of exercise you’re doing. Moreover, most people significantly overestimate the the number of calories that they burn with exercise. So most people are best off doing their training for muscle growth, strength, development, sports, or whatever fitness goals you have, and letting the diet take care of the fat loss. Whether you eat less or you exercise more does not impact the efficacy of your fat loss approach. You’ll get the exact same results from eating 500 calories fewer or burning 500 more calories. So let your training take care of your fitness goals and let your diet take care of getting abs. Abs are made in the kitchen, as the cliche goes. So in terms of what physical activity is best to lose fat, it’s pretty much anything goes. Know what I’m sayin’?

Question two: How to get bigger arms?

Getting bigger arms is the same as getting bigger anything else. Any other muscle group that you want to get bigger? It all comes down to the same thing. I researched where different muscle groups based on the currently available data differ in terms of their frequency and volume that they respond best to and there was no difference. If anything, there was a marginal trend for the arms to respond a little bit better, specifically the biceps, to lower training volumes. But I wouldn’t put any stock into that based on what we know, all muscle groups respond the same. So you need sufficient mechanical tension, you need to train hard in a gym or with weights in general, with resistance, and you need to have sufficient time under tension, which mostly comes down to the number of sets per week per muscle group that you end up doing. In terms of specific exercises that I like for the arms I’m a big fan of Bayesian curls. Of course I am because I coined the exercise, but it’s also very efficient exercise because it subjects the biceps to very high stretch and it subjects the biceps to very high tension in the lengthened position as well as in the shortened position. Most traditional dumbbell and barbell exercises do not stimulate the biceps in its lengthened position, which is actually the position where you get the most active and passive mechanical tension. And research has found that these types of exercises cause more biceps growth. I’m also a big fan of leaning concentration curls. These are very similar to preacher curls, but they are a little bit more flexible and you can alter the angle of your arm, which changes exactly how much resistance you get in the top versus middle versus bottom position. So both of these exercises have the advantage that with a little bit of body movement you can get very high tension throughout the entire range of motion. For the triceps research has found, similarly, that we want to subject it to high tension in long length positions, which means for too long head specifically, which is the big part on the back, you want to do overhead extensions. And research has found that overhead triceps extensions stimulate more muscle growth than triceps pushups, which are a lot more popular. So I’m a big fan of most overhead triceps exercises. If you have issues with your elbows, then skull crushers are often a problem and I like doing skull overs which are a variation of skull crushers where you let your elbows come back a little bit, which has the advantage of A) stretching that long head a little bit more and B) also taking some of the stress off the elbows. Most people tolerate this exercise a whole lot better than they do skull crushers.

Question three: What are the best high intensity interval training workouts?

Well, I think the better question here is what is the best type of cardio? And as I discussed earlier, the type of exercise that you’re doing doesn’t influence your fat loss results. So in research, very clearly, low intensity steady state cardio and high intensity interval training have the exact same effect on fat loss given the same total energy expenditure. Now, of course, high intensity interval training is very time effective, but it also takes up more recovery resources. And the current data show that high intensity interval training also tends to create a bigger interference effect with your strength training. So if in the same program you are trying to gain muscle or build strength and you are doing cardio in that same program, you can get an interference effect, especially if the volume and intensity of the cardio are high. Now, if high intensity interval training, by definition the intensity is going to be high. So especially if you’re performing them on the same day you can reduce the amount of muscle growth and you can reduce the amount of strength development that you’re getting from your strength training. This is called the concurrent training effect or the interference effect. And this effect is a little bit worse, it seems, for high intensity interval training than for low intensity, steady state cardio. So high intensity interval training is great for sports that are essentially high intensity interval training like soccer and it’s a very time effective way to burn calories if that’s your primary goal. But generally for fat loss, if you’re also doing strength training, as you definitely should, because strength training actually is most time effective of all forms of exercise that you can see in this video here, I generally recommend that you do low intensity, steady state cardio, or more importantly, some type of cardio that you can stick with and you enjoy. Because cardio for most lifters is not their favorite part of the program.

How many times a week should I exercise?

Well, that mostly comes down to your schedule, your personal preference. Of course, you can get better results but with more exercise. Up to a point. General recommendations for health actually include about 5 hours of exercise, including 2 hours of strength training. So I would say that most people, if health or fitness is your priority, you should be exercising for about 5 hours a week. the exact number of times you go to the gym doesn’t actually matter that much because it’s all about the total volume of exercise that you’re doing, and that goes for both endurance training and for strength training. Research is quite clear that the total amount of volume that you accumulate in the week is what really matters for muscle growth, strength development and even endurance for the most part. So it’s not so much about how often you go to the gym. It’s about the total volume of exercise that you’re doing in the week. And if you only have time to go to the gym a few times or if that’s more convenient for you, you can do longer sessions. And if you live next to the gym and you can go everyday then you could do shorter sessions. You probably get a little bit better results with higher frequency because if you stretch your sessions out across more days of the week, then you are less fatigued in every session and your performance will be a little bit higher. Therefore, even given the same total number of sets, sort of same time, you generally get a bit better performance and therefore more total volume. As I explained in my recent video on what creates muscle growth This is illustrated well by a recent study by Neves et al from 2022. They compared three conditions. One group did nine sets once per week. One group did three sets three times per week and the other condition did the three sets three times per week equating the volume to the group doing nine sets once per week. Now what happened is that doing nine sets once per week have led to the same gains in muscle cross-sectional area, muscle growth when the total repetition volume or the total work volume I think they used in the study, that leads to the same thing if you’re using the same weights, was equated. In other words, it didn’t matter. Whether you train a muscle once or three times a week, If the total amount of repetitions that you’re doing remains the same. However, if you spread out your volume over more sessions, it does not normally keep your number of reps the same. That’s something academics do in their research studies because it equates for the effect of training volume and we want to isolate variables. But in practice, in a gym where we’re training, we are not in a volume equated condition. So what happens and in this study, this also happened, when you let people do three sets three times per week instead of nine sets in one day. You get more reps. When you do it in three sessions than if you do it in one session because you are more fresh every time you’re training. So in this case, instead of about 2% increase in quadriceps cross-sectional area from the group training once per week or three times per week with the same volume, the group that was training three times per week now left to their own devices, meaning they increased their total training volume, they got approximately double the muscle growth, 4% increase in muscle quadriceps cross-sectional area.

Question five: How to build muscle?

So if you’re asking this question you are probably at step zero. So I’ll focus on like the very big picture things that you should know. Stimulating muscle growth is all about stimulating the muscle with enough time under tension with sufficient tension. So you need to train hard. You need to do strength training or resistance training in general. You want a high protein diet and then you just want to give it a lot of time. That is the most important. So you want to do heavy strength training, sufficient total training volume, high protein diet. Those are really the big picture elements on how to build muscle.

Question six: What time of day should I exercise?

Well, again, first and foremost, the best time of day to exercise is when it suits your schedule and what you can stick to. However, if you have the luxury of choosing between different times then there is some research that indicates that in the evenings to late afternoons you get better results. For example, this study by Küüsmaa and all found that muscle growth was a little bit higher, and this is the best study we have on the topic, in the group training in the afternoons versus the group training in the mornings. Now, that doesn’t mean you can’t gain any muscle or strength when you train in the mornings. In fact, most studies, especially shorter studies, they don’t find significant differences. So this is really a matter of fine tuning. And if you can stick to a certain time in particular, what happens is that your biorhythm can adapt and your body can do very well even training in the mornings when you’re not used to training in the mornings. Caffeine can also help. If you take caffeine before a morning workout, it reverses much of the negative effect of training early in the morning when you’re by a rhythm is not accustomed to training with maximum intensity. Because that is the reason that in the afternoon, theoretically you perform a little bit better and therefore probably also make better gains long term. It’s that your body rhythm, especially your core body temperature is more optimized. So you have higher core body temperature. That’s also why we see that most world records are actually broken in the afternoon to early evening because that is the time of day that our body is most primed for performance. But again, your body and your biorhythm can adapt variable to training in the morning or any other time that you want, especially if you are consistent with that. So try to find a time that you can be consistent with. That is the most important. All right. That is it for the webs top six exercise science questions. Probably a bit more novice level than most of my content, but I hope you got something out of it. If you like this type of evidence based fitness content I’d be honored if you like and subscribe.

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About the author

Menno Henselmans

Formerly a business consultant, I've traded my company car to follow my passion in strength training. I'm now an online physique coach, scientist and international public speaker with the mission to help serious trainees master their physique.

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