SHOULD YOU DO HIIT TO GET FIT?

Posted on March 6, 2017 by sbromlow

Have you ever found yourself at the gym on an elliptical or treadmill wondering if there was better and faster way to do cardio for fat loss? A new style of training known as high intensity interval training (HIIT) might just be your solution. Many fitness bloggers who advocate HIIT say that it is better than moderate intensity steady state (MISS) cardio because it burns more calories in a shorter amount of time as well as increases your metabolism and burns calories even after you are done working out due to something called the EPOC effect. On the other hand, there are some people who say that moderate intensity steady state cardio is better than HIIT cardio because MISS primarily uses lipids as a fuel source, and therefore burns more fat. But is one really better than the other?

In 1996, Dr. Izumi Tabata performed a study on the effects of moderate intensity training and HIIT, in order to better understand which method was more effective for preparing olympic athletes for events. For his experiment, he studied two groups. The first group exercised at 70% of their VO_2maxfive times a week on a treadmill. He compared this protocol with the Tabata protocol and found that the Tabata group was exercising at an intensity of 170% VO_2max. In the end, the two groups both had increases in aerobic capacity, but when anaerobic fitness was analyzed, the Tabata protocol group increased by 28% while the other group remained the same. This means that high-intensity interval training actually improves both anaerobic (muscle building) and aerobic (fat burning) body systems, while moderate intensity exercise only improves the aerobic system. Additionally, the Tabata group lost more weight on average and gained more muscle than the MISS group. The results obtained from this study ultimately helped legitimize a movement away from chronic cardio and toward high-intensity workouts.

SO, WHAT IS HIIT?

HIIT is a type of training in which intensity and heart rate is varied throughout a workout, as opposed to MISS which is exercising on a treadmill, elliptical, etc. and maintaining your heart rate around 125 bpm for 30 to 60 minutes. During the high intensity intervals, your heart rate should be around at least 160 beats per minute, and during the low intensity intervals around 100 bpm. A typical HIIT workout might look something like this:

Exercise 1: Push-ups

Exercise 2: Jump Squats

Exercise 3: Burpees

Exercise 4: V-ups

Start with push-ups. Perform them for 20 seconds at a high-intensity. Rest for 10 seconds, and then go back to doing push-ups for 20 seconds. Once you complete eight sets of push-ups, rest for one minute. Next, move on to jump squats and repeat the sequence of 20 seconds on, 10 seconds off. Once you finish eight sets of jump squats, rest for one minute, and then do burpees. After burpees, finish the workout with V-ups.

EPOC: Excess Post-Exercise Oxygen Consumption

Since you burn roughly the same amount of calories during a HIIT and MISS workout, The big debate over HIIT vs MISS cardio for fat loss comes down to how many calories you burn after a workout. Most of the misinformation circulating around HIIT vs MISS cardio is centered around EPOC. This term simply refers to the process of restoring your body to a normal resting state after exercising. During this time, your body uses energy and burns calories while recovering and building muscle. The big debate is whether the EPOC after doing a HIIT workout has significant effects on weight loss or not. One fitness blogger said that “new age Tabata style workouts burn 50-70 calories during a workout and 300-400 post workout over the next 24 hours.” The truth is, you are more likely to burn around 300 calories during a HIIT workout and about 40 after. The claim made above would require an EPOC of over 100%, and since EPOC generally doesn’t surpass 30%, this claim was clearly not based on scientific evidence, and can be very misleading to uniformed readers. One study reported an EPOC of 25% after a very intense and strenuous high intensity workout and 10% after a moderate intensity workout, but even though high intensity workouts have a higher EPOC than moderate intensity workouts, the amount of additional calories burned due to the EPOC effect is not very significant. It is important to keep in mind that although these numbers may appear to be convincing, the difference in calories burned, is only about 30 calories, which is much easier to achieve simply by dieting.

Even though the EPOC theory turned out to be false after all, one study did show that HIIT training increases muscle mass and therefore increases the capacity to burn fat, so in the long run, HIIT could actually be booting your metabolism. HIIT also has a lot of other health benefits to offer. For example, one study found that HIIT training greatly improved cardiovascular endurance and that subjects who went through two weeks of HIIT training experienced a drop in their resting heart rate, indicating better cardiovascular health. Some people forget that their heart is a muscle. If you keep it beating at a constant rate, then it doesn’t have to work harder, and therefore it isn’t getting any stronger. This can be a problem for people who regularly stick to the elliptical or treadmill and never reach at least 80% of their max heart rate.

Overall, there is not a big difference in the number of calories burned between HIIT and steady-state cardio, but HIIT may have some additional anaerobic and cardiovascular health benefits. Deciding whether to do HIIT versus MISS can also depend on a variety of other factors. For example, your diet. If you are on a low carb diet, or are carb cycling, you may want to do a MISS workout on low carb days rather than a HIIT workout because HIIT requires a lot of carbohydrate (glucose and glycogen), whereas MISS primarily uses lipids for energy. Also, if you are doing weightlifting in addition to cardio, MISS might be a better option because HIIT offers some of the same benefits as weightlifting. Another thing to consider is that HIIT is very strenuous, and it may be challenging to jump right into an advanced HIIT workout especially if you are just beginning an exercise program. That being said, if you are the type of person who prefers weightlifting and doesn’t need to incorporate as many body weight exercises into your workout regime to build muscle, then by all means, stick to weightlifting and steady state cardio. However, if you like doing HIIT workouts either because they take less time to do or because they don’t require any fancy gym equipment, that’s also fine. Whatever your personal fitness goals and workout preferences are, the most important thing is always to listen to your body and do what’s best for you.

Questions and comments:

Which do you personally prefer, HIIT or MISS?

If you previously did HIIT because you believed you were burning hundreds of calories post-workout, do you think you will still continue doing HIIT now that you know the after burn effect isn’t true?

Comment below if you’d like to share any thoughts about HIIT or if you have any questions.

Thanks for reading:)

Free Weight vs Machines: Is One Better Than the Other?

Posted on March 6, 2017 by adehope

Searching for the best possible way to make gains in the gym can often be tricky or overwhelming. When you walk into the gym you can probably find a wide range of weight machines along with rows of dumbbells and squat racks. Many lifters incorporate a mix of free weights and machines when they are training. Free weight exercises require balance and they allow for movement in multiple planes while weight machines provide movement over a fixed range of motion. Some people swear by free weights alone and wouldn’t dare touch an exercise machine at the gym. Others solely use weight machines in their workouts. Which method of lifting is the best way to get in shape?

The benefits of using weight machines are that they are easy to use and figure out which is especially helpful for beginners. They are considered “safe” in the sense that you will not drop a heavy weight on yourself or someone. It is also easier to change resistance and loads on a machine. However, the movements one makes on a weight machine do not imitate natural movements we make every day. The exercises done on a weight machine usually do not target large muscle groups so isolated training is required.

The advantages of free weights are that they mimic real world movements and they target larger muscle groups, working more muscles in one exercise at a time. They require the use of stabilizing muscles so one must balance to perform the exercises. This coordination is part of the reason they are more natural movements that can help in day to day activities. Common disadvantages are that they are intimidating to beginners and some exercises require a spotter.

Lifters often quantify their strength by their one repetition maximum (1RM) or the heaviest weight a muscle/muscle group can successfully lift just one time with correct form. A study published in the Journal of Strength and Conditioning compared the force produced by muscles when squatting and bench pressing free weights or in a Smith machine. The results showed that participants had a greater 1RM in squatting with a Smith machine. Alternatively, participants had a greater 1RM when bench pressing using free weights. A previous study comparing free weight squats and bench press to machines showed greater 1RM in machines than in free weights, however the differences were not significant.

Example of a man squatting under a smith machine.

Another study done by Schick et. al. (2010) was conducted to compare the activation of muscles when bench pressing on Smith machine or a free weight bench press. The results found that there was significantly greater activation of the medial deltoid in the free weight bench press than in the Smith machine bench press. The instability caused by the free weight bench press requires more use of medial deltoid to both stabilize the body and produce the force necessary to lift the weight. The results did not show differences of activation in the larger chest muscles. The study used experienced and inexperienced lifters to determine whether one exercise was better beginners or not, but they did not find any significant differences between groups. It should be noted, however, that the study defined experienced as someone who consistently benched twice a week for 6 months. It may have been more helpful to use subjects with some more time and experience lifting.

The studies conducted do not necessarily favor any mode of exercise over another. I believe that more experiments should be performed to study the long-term effects of using free weights vs machines and whether one method may lead to faster results.

When deciding on whether to choose to lift using free weights or machines, it is best to determine what your goals are. If you want to be more efficient in the gym and use the most muscles in less exercises, free weights are your best bet. If you do want to isolate certain muscles and have more time to spare weight machines will work well. Many people incorporate both free weights and machines in their workout regime. I think it is most important to keep in mind that free weights are safe and activate more muscles when performed correctly. While weight machines may help in making you stronger, they avoid working those stabilizing muscles to help with balance. So, when your buddy needs help moving his couch up 3 floors to his apartment, you might wish you trained with free weights instead.

Nah Coach, I don’t have to stretch.

Posted on March 5, 2017 by Kathryn

Ever wondered if those pre- and post- workout sessions really make a difference in your daily exercise regimen? It is commonly believed that stretching prior to and following a workout will decrease the likelihood of injury, minimize post workout pain, and increase performance. However, other athletes and trainers believe that stretching has no impact on these factors and can even decrease strength and performance. But what are the facts?

Figure 1. Examples of active and passive/static and dynamic stretching.

There are several subgroups of stretching but I will focus on performance results with regards to the two most well researched types: static versus dynamic. Each stretch can be done actively or passively, where active stretching is when you contract the muscle in opposition to the one you want to stretch and passive uses an external force such as a strap, the force of your body weight, or gravity. Each type of stretching, shown above, has been shown to impact exercise in different ways. Let’s start with the most frequently used type, static stretching, where a person slowly moves muscles until they reach the brink of pain and hold that position for 20-30 seconds.

Static stretching has been compared to continuously stretching a rubber band. Immediately after stretching the rubber band, the band remains limp as it contracts slowly back into its original form, similarly to the behavior of a muscle. It seems unrealistic to expect a maximum amount of contraction and force immediately after stretching your muscle. In more physiological terms, the loss of muscular stiffness caused by static stretching results in an increase in length of sarcomeres in each muscle fiber, decreases contact between actin and myosin, and therefore decreases the force produced (Shrier, 2004; Kokhonen et al., 2004).

Figure 2. Actin and myosin movement in relaxed muscle versus contracted muscle. The less contact between actin and myosin, the less force produced.

One study by Fletcher and Jones (2004) on 97 male rugby union players showed a significant decrease in sprint times for the passive static stretch group. This could be due the mechanical impact of stretching on the muscle, kinematic differences, or neural inhibition which decreases the neural drive to muscle. Dynamic stretching focuses on moving through a range of motion repeatedly and mimics motion that will occur during exercise. Fletcher and Jones’ (2004) study showed more beneficial performance results from active dynamic stretching prior to sprinting though. The active dynamic stretch group of rugby players improved their sprint times significantly.

These results could be explained by information in a systematic review of studies on stretching and exercise by McGowan et al. (2015). This review showed that dynamic stretching increases the temperature of the muscle more than static stretching. This increase in temperature activated an increase in muscle metabolism, elevated oxygen uptake, and increased the power output of the muscle. Another study by Gray et al. (2008) showed a correlation between increased muscle temperature and faster ATP turnover, caused by an elevated rate of creatinine phosphate utilization and H+ accumulation. The elevated muscle temperature also resulted in short term (~2 minute) increase in anaerobic glycolysis and muscle glycogenolysis. These physiological responses, in theory, would result in greater power production during sprint and sustained high-intensity exercise, however high quality research results on this topic are limited.

Several literature reviews regarding this topic exist, but compiling results from hundreds of varying studies makes it difficult to normalize the results. Several reviews analyzed results that were not statistically significant, skewing the review results. By looking at the methods researchers used to gather and compile data and at the sources they cited, I was able to identify the sources where results were significant and relevant. The review also covered studies on a span of sports from swimming, to sprinting, to jumping, all which are impacted very differently by stretching, which makes the conclusions for these reviews far reaching statements. When more studies are done within each of these sports, reviews that group together specific events and exercises will provide more beneficial results.

When looking at the impact of stretching on pain, several papers used self-reported ratings of pain to measure differences. In those studies the results did not show a significant difference between ratings from groups that stretched and controls. Self-reported measurements of pain contain bias which makes them difficult to compare between groups of people. Some papers overcame bias by observing differences in delayed muscle soreness by measuring creatine kinase levels, a commonly used marker for muscle damage. One experiment by Buroker and Schwane (1989) showed no significant difference in creatine kinase levels from stretching post-exercise. Very few studies are done solely to measure the effect of post-exercise stretching on soreness and risk of injury so it is difficult to differentiate these results from the pre-exercise stretching.

Keeping these biases and knowledge gaps in mind when considering the results of these papers, it is plausible that for the majority of exercises, dynamic stretching can positively impact your performance. This is largely due to the fact that it increases the core body temperature and targets activity in specific muscles that will be used instead of just stretching them. Static stretches prior to a workout seem to have no impact or a negative impact on performance since the muscle needs time to recover and regain stiffness before use. Personally, this would convince me to do some dynamic stretches before my next run rather than static stretches. While it differs from sport to sport, dynamic stretching appears to be the ideal pre-exercise stretch to optimize performance.

Recommended Further Reading:

1. Blahnik, Jay. Full-Body Flexibility, Second Edition. Available at: http://www.humankinetics.com/excerpts/excerpts/types-of-stretches

2. Sifferlin, Alexandra. Why Stretching May Not Help Before Exercise. (April 08, 2013) Available from: http://healthland.time.com/2013/04/08/why-stretching-may-not-help-before-exercise/

3. Shrier, Ian. Sports Med (2004) 14:267-273. Available from: http://www.elitetrack.com/article_files/stretchingreview.pdf

4. Kokkonen, J., Nelson, Α. G., Cornwell, Α. (1998). Research Quarterly for Exercise and Sport. 69 (4): 411-415. Available from: https://www.ncbi.nlm.nih.gov/pubmed/9864760

5. Fletcher, IM, Jones, B. J Strength and Condition Research. (2004) 18(4), 885-888. Available at: http://staps.nantes.free.fr/L3/entrainement/etirements/THE%20EFFECT%20OF%20DIFFERENT%20WARM-UP%20STRETCH.pdf

6. McGowan, C.J., Pyne, D.B., Thompson, K.G. et al. Sports Med (2015) 45: 1523. Available at: https://link-springer-com.udel.idm.oclc.org/article/10.1007%2Fs40279-015-0376-x

7. Gray, SR, Soderlund, K, Ferguson, RA. J Sports Sci. (2008) 26(7):701:7. Available at: https://www-ncbi-nlm-nih-gov.udel.idm.oclc.org/pubmed/18409101?dopt=Abstract

8. Buroker, KC, Schwane, JA. The Physician and Sportsmedicine (1989) 17(6): 65-83. Available from: http://www.tandfonline.com/doi/citedby/10.1080/00913847.1989.11709806?scroll=top&needAccess=true

LISS vs. HIIT Training Sessions – Can both lead to Weight Loss?

Posted on March 1, 2017 by lzak

Although exercise can provide many health benefits, many people look at it as a simple way to help them lose weight. However, intense exercise may seem daunting to populations who are new to exercise or recovering from injury. Therefore, the question arises of whether it is possible to lose weight with low intensity exercise. In this news article, published by The Telegraph, they take a look into each form of exercise and how they effect weight loss.

The author, Lucy Waterlow, claims how “the HIIT philosophy has been behind every new exercise class, bestselling book and rising YouTube fitness star” The fitness acronym stands for High Intensity Interval Training and typically requires you to keep your heart rate at at least 85% of its maximum capacity throughout the workout. However, for people with injuries of any kind this method of exercise is a bit more difficult. Therefore, LISS has been heavily emphasized as of late as being the new and improved way to keep your weight under control and putting less of a strain on your body. LISS stands for Low Intensity Steady State and requires you to keep your heart rate between 60-80% of its maximum capacity.

The article references a recent study by the University of Bath, which found that “LISS can be just as effective as HIIT when it comes to weight loss”. Theses results came from a study in which they asked people of a similar age to exercise five times a week at either high or moderate intensities. Their results showed that after a three-week period, both groups had lost the same amount of weight. Dr Jean-Philippe Walhin, a human physiology research fellow who carried out the study, quotes ‘What really matters is how many calories were used up by exercising in total.’

The articles continues with an additional argument claiming that LISS may motivate people to work out more since it isn’t as stressful on your body. This way, you are able to increase your physiological health and motivation at the same time without the high risk of injury that may occur with High Intensity Interval Training. In conclusion, the article highlights the benefit of LISS workouts and how they are comparable to HIIT workouts in weight loss.

I believe this is a relevant article to the Engineering Exercise course as it looks at two different, popular types of training and how they affect weight loss. Although “the best way to lose weight” will always be a hot topic, I think it is important to recognize that different exercises are better for different people based off of their medical history.For example, the idea of going to the gym for a cross fit class may scare someone who is obese out of working out at all. But, the idea of 45-minute brisk walk may appeal to them more and benefit them physiologically rather than not working out at all. It becomes a cross between physical therapy, where exercises are designed for the individual, and research, where the latest and greatest ideas for weight loss are tested.

In my opinion, I thought this article was interesting in its approach to the general public but was lacking in the hardcore data. However, I felt this is expected in a “Lifestyle” piece and found it interesting to see how referencing studies and quoting doctors may be enough to convince the general public about health and fitness, regardless of whether hard data was presented. When I looked into the argument of LISS vs. HIIT workouts further, I found a source that provided more detailed information to prove their points and support their argument. In Martinez’s “Cardio for Fat Loss“, he focuses on the pros and cons of each kind of training and how they benefit you in weight loss. I found this to be more beneficial than the original article as it stated straight facts about both, and let the reader decide which is better for their situation. The underlying conclusion was that “HIIT is quicker, proves to be more effective for fat loss, creates metabolic changes, and helps with muscle retention but not everybody can do HIIT. LISS is safer, but takes twice as long to accomplish similar things and it still has its place for fat loss in moderate amounts, from a pure calorie burning standpoint (meaning only to burn calories & not make changes to your metabolism)”. This was helpful in looking at weight loss from a metabolism standpoint, rather than just pure fat loss. In conclusion, it is beneficial to know that despite differences, both HIIT and LISS workouts can lead to some form of weight loss.

Reccomended for Further Reading:

Lucy Waterlow, “Ditch those heart-thumping HITT sessions: low intensity exercise is the best way to work out” February 23, 2017. Available from: http://www.telegraph.co.uk/women/health/ditch-heart-thumping-hiit-sessions-low-intensity-exercise-best/

Chris Martinez, “Cardio for Fat Loss: High Intensity Interval Training Cardio vs. Low Intensity Steady State Cardio”. February 15, 2017. Available from: http://www.simplyshredded.com/cardio-for-fat-loss-high-intensity-interval-training-cardio-vs-low-intensity-steady-state-cardio.html

BMEG442: Engineering Exercise and Sports

Applying engineering principles to exercise

Monthly Archives: March 2017