By: Allison Naumann, Claire Paddock, and Christian Poindexter
Recommended Further Reading:
By: Allison Naumann, Claire Paddock, and Christian Poindexter
Recommended Further Reading:
By Andrew Taylor and Kathleen Wright
Figure 1. Women participate in a HIIT class.
How many of us have said we would go to the gym, only to realize later that we don’t have the time? High-intensity interval training (HIIT) classes have increased in popularity over the last few years, partly because the sessions are shorter than traditional workouts. HIIT workouts alternate short (20 or 30 second) intervals of maximum exertion with periods of rest or low-intensity exercises. Elite athletes might take part in HIIT to improve their aerobic energy metabolism and performance. If you have ever played a demanding sport, you have probably been subjected to HIIT during the game or practice. The recent obsession with HIIT raises the question: is it just a fad, or will it stick around as an effective means of exercise?
HIIT can be defined as brief exercise that generates a VO2peak, or 90% of the maximum VO2 potential, commonly followed by a relaxation period. This study utilized the Wingate test: participants repeated 30 seconds all-out maximal cycling on a specialized ergometer, with 4 minutes of recovery in between, for a total of 2 to 3 minutes of intense exercise. The authors focused on specific markers in skeletal muscle metabolic control; they determined an increase in skeletal muscle oxidative capacity after 2 weeks of HIIT. They also found that changes in carbohydrate metabolism (Figure 2) were comparable to adaptations from endurance training. Although exercise performance improved, there was no measurable change in participants’ VO2peak after 2 weeks of HIIT. However, this study did not fully investigate how HIIT affects the cardiovascular and respiratory systems, or metabolic control in other organs.
Figure 2. Results depict the glycogen content, or resting carbohydrate dry weight, found in skeletal muscle during rest and 20 minutes after exercise, both before and after 2 weeks of HIIT.
Additional HIIT data concerning VO2peak and citrate synthase activity support the previous claim that HIIT provides similar benefits to endurance training. This review recognizes that Wingate-based training may not be tolerable for everyone, and instead tested low-volume HIIT. The authors found that their model was time-efficient and effective in producing cardiovascular and skeletal muscle adaptations. They reference the results of similar studies, saying that HIIT is superior to moderate-intensity continuous training (MICT) in increasing cardiorespiratory fitness and endothelial function. However, researchers still don’t know what intensity or training volume is required to be effective.
A study concerning overweight and obese adults found that HIIT had similar results to MICT, in terms of body composition measures, but HIIT required less training time. They concluded that HIIT may be a time-efficient way to manage weight. Meanwhile, this systematic review determined that MICT and HIIT provide similar benefits for body fat reduction, but HIIT was no more time-efficient than MICT.
The data from these studies indicate that HIIT is comparable to MICT, similar to the difference between traditional and functional workouts, as described previously in this post. High intensity workouts can be very demanding, as seen with the Wingate test, and may not be suitable for all individuals. HIIT should not be substituted for specialized athletic training, but can be beneficial for athletes who need to quickly use their bodily carbohydrates. Many HIIT studies are short-term, like the first study we mentioned, and further research needs to be conducted to determine the long-term effects of HIIT on cardiovascular and respiratory systems. Although HIIT attracts people with the allure of getting fit fast, there isn’t enough data currently to support that HIIT is actually more time-efficient than endurance training.
Questions to Consider:
Should HIIT workouts be recommended for the average person?
Why could an increase in glycogen dry weight be considered important for exercise?
How could your current workout routine benefit from HIIT?
What athletes do you feel would benefit most from HIIT?
Recommended Further Reading- Works Cited
By Eryn Gerber, Destiny Neumann, & Andrew Reynolds
Suggested Reading/Works Cited:
Recently workout fads have been popping up all over mainstream media and in different fitness centers. Everyone seems to have the ultimate plan to burn fat and build muscle, these routines have become more intricate and choreographed, often requiring a coach or instructor to oversee the work out. Older workout conventions have had to adapt to meet the changing needs and desires from society. We are here to figure out, is CrossFit the ‘glow up’ of Body building or are these two style of exercise completely unique?
First, what are CrossFit and bodybuilding?
CrossFit is recognized as one of the fastest growing high intensity functional training regimens to date, popping up in 142 countries worldwide. But what is this mysterious new fad and does it actually work? The purpose of CrossFit training is to get as ‘fit as personally possible’, but is not specifically focused on just one fitness area. CrossFit aims to optimize physical ability not only in strength, but in cardiovascular endurance, flexibility, power, speed, coordination, agility, balance, and accuracy as well . This lead trainers to develop a plan that incorporates multiple training theories into one ‘Workout Of the Day’ to keep a variety of fitness elements working.These workouts involve elements from gymnastics, weightlifting, and cardiovascular exercises which are performed quickly with little rest between sets.
The goal of Bodybuilding (muscle specific) training is so lose as much fat content as possible while maximizing your bodies muscle mass. This kind of training is where terms like ‘leg day’ and ‘back day’ came from, it is devoting an entire workout to a few muscle groups and working them to exhaustion. When you undergo this type of training your body experiences hypertrophy of all muscle fiber types. A bodybuilding workout focuses on keeping the heart rate steady and high weight low rep exercises to slowly break down and rebuild one’s muscle fiber. This is proven to be an effective method if one is only worried about shear size and growth of muscles .
After hearing this do you believe they are the same? Here’s what science said.
The approaches of these two exercise styles are most definitely unique, but are the fitness results actually all that different? In one research study called “Functional vs. Strength Training in Adults” 101 subjects, averaging an age of about 55, were separated into two groups that each performed 24 sessions of (functional or strength) training protocol twice per week. Each subject was assessed before and after the study using a quantitative Y-balance test and a qualitative Functional Movement Screen test. The changes between pretest and post test were analyzed and results showed that there were no significant differences in improvement between the training protocols as a whole. However, functional training was less effective for women compared to men in the same group . The variability in prior athletic training must be taken into consideration when interpreting these results. Some participants may have needed additional training to better their basic skills before partaking in these specific training protocols.
Another study looked at ‘The effects of high-intensity intermittent exercise(HIIE) training on fat loss and fasting insulin levels of young women” comparing the effects of CrossFit(HIIE) training to steady state weight lifting over the course of 15 weeks(exercising three times a week). While this study focused on insulin levels they reported a variety of information on lean body mass, fat content, and weight loss that can be used to draw conclusions about the exercise types as well, see that diet was not changed between the groups. This study showed that women who underwent the CrossFit style training showed a significant decrease in total body mass(they lost more weight) 3.5kg weight loss, compared to the steady state weight lifters who showed a 0.5kg increase in body mass. Demonstrating that while CrossFit participants and bodybuilders may both be used for strenuous high demand exercise, CrossFit is a more effective method of losing weight whereas bodybuilding promotes the act of ‘bulking up.’ While this study was full of information, it does not completely validate the idea that Crossfit and Bodybuilding are the same results with a different method it does help share some information that can point future studies in the right direction.
Based on what we have found we can draw a similar conclusion to previous posts about these training styles. We concur with the groups from previous years that current studies show that while the methods of achieving a lower fat content are different, the overall outcomes of the training types are very similar. In order to better compare these two very different approaches to fitness, there needs to be more extensive research done. The current scientific literature related to CrossFit specifically is lacking. Few studies with high level of evidence at low risk of bias have been widely recognized . As of now we cannot truly compare this new workout fad to the traditional bodybuilding without more extensive studies with conclusive evidence.
By; Ellen Dudzinski and Destiny Neumann
Questions to consider:
Karavirta, L., M. P. Tulppo, D. E. Laaksonen, K. Nyman, R. T. Laukkanen, H. Kinnunen, A. Häkkinen, and K. Häkkinen. “Heart rate dynamics after combined endurance and strength training in older men.” Medicine and science in sports and exercise. July 2009. Accessed March 06, 2018. https://www.ncbi.nlm.nih.gov/pubmed/19516157
Aagaard, P., and J. L. Andersen. “Effects of strength training on endurance capacity in top-level endurance athletes.” Scandinavian journal of medicine & science in sports. October 2010. Accessed March 06, 2018. https://www.ncbi.nlm.nih.gov/pubmed/20840561.
Fitts, R. H., and J. J. Widrick. “Muscle mechanics: adaptations with exercise-training.” Exercise and sport sciences reviews. Accessed March 06, 2018. https://www.ncbi.nlm.nih.gov/pubmed/8744258.
Fitts, R. H., D. R. Riley, and J. J. Widrick. “Functional and structural adaptations of skeletal muscle to microgravity.” The Journal of experimental biology. September 2001. Accessed March 06, 2018. https://www.ncbi.nlm.nih.gov/pubmed/11581335.
If you’ve participated in any athletic event, you know that one of the first things you do is to start stretching before any activity takes place. Coaches and trainers emphasize that stretching should occur on a regular basic, and become part of an individual’s workout routine. These stretches are usually static stretches (holding a stretch for 20-30 seconds). The intent of prescribing stretching before exercise, is based on the assumption that by stretching you enhance performance, prevent injuries, and increase flexibility. However, several studies, including one from the Journal of Applied Physiology, Nutrition, and Metabolism, have shown that stretching before exercise can actually do more harm than good, and increase your risk of injury.
While stretching before exercise does activate the muscles and increase blood flow to the areas as a “warm up”, it can be potentially very detrimental to an athlete’s workout. This conclusion is especially pertinent when the sport in question requires maximal force production. In a study conducted at the University of Nevada, researchers determined that leg muscles generate less force after static stretching than if they did not stretch at all. When muscles are subject to the strain of static stretching, they remain in a weakened state, thereby temporarily reducing the force that it can produce. The researchers evaluated two types of stretching, ballistic (bouncing) and static (control is no stretching). After stretching for 3 sets of 30 seconds, subjects performed a vertical jump on a force plate. Power values were compared for each of the conditions (Figure 1). From this graph it is clear to see a significant difference in the power values observed in the control group and static group. The decrease in power after stretching could inhibit a good muscle building workout. For sports that require maximum power (ex. football), static stretching should be limited before activity.
Static stretching intervals should last for no more than 60 seconds, or moderate reduction in maximal muscle performance may be observed. In a study conducted by Behm et. al. the effects of static stretching on power-speed and strength tasks were compared. One of the main components of this study involved investigating the relationship between time spent holding a stretch and subsequent performance in a physical activity. In order to perform these tests, two groups of healthy and active adults were randomly assigned, with one group holding their static stretch for less than 60 seconds and the other for a period of time greater than 60 seconds. On average there was a mean reduction of muscle performance for both test groups, but the group that held the stretch for a longer period of time experienced significantly higher reduction rates in performance. For the individuals that held the stretch for less than 60 seconds, a mean reduction of 1.1% was observed and categorized by the researchers as a small reduction in performance. However, a moderate reduction of 4.6% was noted in the population that held the stretch for longer than 60 seconds, indicating that there is a dose-response relationship between stretching and maximal muscle performance.
To investigate this relationship further, two types of physical activity were studied. Power-speed tasks were given to both groups and the results supported the notion that on average static stretching, especially when held at higher intervals, impaired muscle performance in the test subjects. While only a small mean reduction rate of 1.3% was observed for this type of exercise, this change could be extremely detrimental to an athlete’s performance where maximal speed is critical (i.e. sprinters). Power tasks were also completed, and the negative effects of static stretching on performance became more apparent. On average there was a 4.6% reduction in an individual’s maximum muscle performance, with a higher instance of 5.1% reduction when the activities were completed after a period of stretching lasting longer than 60 seconds. In another study also conducted by Behm et. al, these findings were not only supported by additional trials, but also expanded upon to look at the long term effects of stretching on overall performance. In his initial study that looked at power and speed tasks, maximal muscle performance was calculated minutes after the the stretching was complete. The second study, however, observed the prolonged effects that static stretching would have on an athlete, and concluded that even 2 hours after the last set of static stretching, instances of decreased performance existed.
The results from these studies suggest that time spent holding a stretch and subsequent muscle performance have an inverse relationship. For this reason more and more coaches and athletes are looking to implement a different approach to their warm up routine.
Dynamic stretching (Figure 2) is simply the act of stretching your muscles while moving, and it is an effective method to get your blood flowing and increase your power, flexibility, and range of motion prior to working out. This type of stretching is unique in that the activities performed have the ability to target specific muscles necessary for the task at hand. In other words, different forms of dynamic stretching would be used for a sprinter and a volleyball player because each sport requires a different amount and variety of muscle activity. Dynamic stretching allows athletes to engage their bodies’ muscles in a way that static stretching cannot, thereby quickly earning its place as a replacement to static stretching in many pre-workout routines.
While the value of traditional static stretching before exercise may be an outdated concept, the benefit of increased flexibility in athletes should not be ignored. For this reason post workout stretching is recommended as a “cool down”. If necessary, short duration, lasting less than 30 seconds, low intensity static stretches could be implemented before activity to get blood flowing to muscles and reduce stiffness, but this does not offer the best possible results. The ideal warm-up routine for athletes to minimize risk of injury and maximize performance should include aerobic activity, dynamic stretching, and sport specific dynamic exercises.
Questions to consider:
How would the stretching routine you made for football players differ from that of a sprinter?
There is a lot of information about how bad form or technique during exercise can cause injury, should there be attention called to the potential adverse effects of stretching improperly?
Samuel, M. N., Holcomb, W. R., Guadagnoli, M. A., Rubley, M. D., & Wallmann, H. (January 01, 2008). Acute effects of static and ballistic stretching on measures of strength and power. Journal of Strength and Conditioning Research, 22, 5, 1422-8.
Behm, D. G., Blazevich, A. J., Kay, A. D., & McHugh, M. (January 01, 2016). Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review. Applied Physiology, Nutrition, and Metabolism =, 41, 1, 1-11.
Shrier, I. (October 01, 1999). Stretching Before Exercise Does Not Reduce the Risk of Local Muscle Injury. Clinical Journal of Sport Medicine, 9, 4, 221-227.
Behm, D. G., & Chaouachi, A. (November 01, 2011). A review of the acute effects of static and dynamic stretching on performance. European Journal of Applied Physiology, 111, 11, 2633-2651.
Shrier, I. (January 01, 2000). Stretching before exercise: an evidence based approach. British Journal of Sports Medicine, 34, 5, 324-325.
Herbert, R. D., & Gabriel, M. (January 01, 2002). Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review. Bmj (clinical Research Ed.), 325, 7362.)
Reynolds, Gretchen. (2008) Stretching: The Truth. The New York Times. Retrieved from: http://www.nytimes.com/2008/11/02/sports/playmagazine/112pewarm.html
Reynolds, Gretchen. (2016) The Right Way to Stretch. The New York Times. Retrieved from: https://well.blogs.nytimes.com/2016/01/21/stretching-back-to-the-past/
Resistance training has many positive health effects including but not limited to increased aerobic capacity, decrease in body fat, and increase in muscle strength. Each of these qualities were used to examine the effects of single versus multi-joint exercises in this research study. Thirty-six male participants were split into two groups to complete an 8-week resistance training program that contained either only single joint (SJ) exercises or only multi-joint (MJ) exercises. Body composition, one repetition maximum tests, and peak oxygen consumption (VO2max) were all measured at the beginning and end of the study. Statistical analysis showed that both groups improved in all categories, with those in the MJ group having significantly larger improvements in VO2max and muscle strength than those in the SJ group.
People question what type of exercises should be part of their training and learning more about the benefits of each will help to optimize training programs. This study kept total load volume the same between the groups which allows for comparison between the groups; however, in actual training programs this is often not the actual switch people would be making if changing exercise types. Other constraints of this study include that it only included male participants and they were all amateur soccer players. Therefore, further studies would be needed to conclude that the same results would hold true for other groups like professional weight lifters, non-athletes, and females.
Other articles on this topic:
Work Cited: Paoli A, Gentil P, Moro T, Marcolin G, Bianco A. Resistance Training with Single vs. Multi-joint Exercises at Equal Total Load Volume: Effects on Body Composition, Cardiorespiratory Fitness, and Muscle Strength. Front Physiol. 2017;8:1105. doi:10.3389/fphys.2017.01105.
According to a paper  published in 2014 in the American Journal of Lifestyle Medicine, that there is a bidirectional relationship between sleeping and working out. Many of us have probably heard about this study, but rarely do we stop and think what would happen to our sleep schedules if we did cease to exercise. We know that we can achieve better and more restful sleeping habits if we workout for 45 or so minutes a day; however, many graduates students, myself included should be spending time in the gym or exercising even in the off season of their sports. This is not even to stay in shape for their sports, but instead, to maintain the sleeping patterns and effectiveness of that sleep. From this article, I learned that we should be forcing ourselves to workout to, of course, benefit from the known effects of working out on health, but also to achieve the indirect benefits of obtaining better sleep patterns and become healthier from that.
1:Kline CE. The bidirectional relationship between exercise and sleep: Implications for exercise adherence and sleep improvement. American journal of lifestyle medicine. 2014;8(6):375-379. doi:10.1177/1559827614544437.
Recommended for Further Reading:
Here we present the AstroJump! Your exercise equipment for your trip to space:
In today’s society, exercise is a part of everyday life. From high school sports and professional sports teams to recreational running and yoga classes, exercise is everywhere. However, many people struggle with breathing during exercise. Gym-goers pant on the treadmill, weight-lifters have trouble lifting their weights, and yoga classes struggle to stay balanced. And, if you’re anything like me, you’ve heard every saying about “breathing in through your nose and out through your mouth” or breathing at certain times while exercising, which can be confusing or overwhelming to do. So, many people ignore their breathing while they exercise and do not regulate their breathing patterns at all. But, many of the exercise difficulties that people experience can be improved by learning to breathe properly while exercising. So, how does this work? And, how does breathing differ between exercises?
The process of breathing involves several chest muscles, most notably the diaphragm. The diaphragm is a dome-shaped, sheet-like muscle that lies underneath the lungs. Not only does the diaphragm separate the chest from the abdomen, it is also the primary respiratory muscle. When we inhale, our lungs expand and the diaphragm contracts, or moves downward, as it flattens. At the same time, the intercostal muscles of the rib cage expand. This expansion of the diaphragm and intercostals and the addition of air in the lungs creates a great deal of pressure inside the body, which will play a large role in breath regulation as we will see later. While inside the body, oxygen is absorbed to create energy in the form of ATP. Then, as we exhale, our lungs return to their resting state and the diaphragm returns to a dome shape. As this happens, the pressure built up during inhalation is relieved through the release of gas as carbon dioxide. But what does all this mean for your exercise routine?
Breathing patterns and the timing of breathing differs from exercise to exercise. Many breathing patterns in sports are based on regulating the build-up of pressure that occurs during inhalation, as mentioned above. Other breathing patterns are meant to maximize oxygen-uptake by the body. But, it’s important to note that each sport or type of exercise requires different breathing patterns.
Running is one sport with no singular convention on breathing. Some people say “breathe in through your nose, out through your mouth.” Others say to breathe in-tune to your running, so inhale on one step, exhale on the next. Still others claim that you should breathe however best suits you to finish a run. So, is there no singular optimal way to breathe when running?
Studies have shown that this is false – there are certain ways of breathing that are less energetically costly and more comfortable for runners. One study supporting this was conducted by McDermott, et al. to analyze the connection between breathing pattern and stride rhythm. In this study, ten subjects ran at various paces while measurements of heel strike and inhalation were recorded. The results showed that runners have a tendency to breathe in a 2:1 or 3:2 pattern most often, meaning inhaling for 2 steps and exhaling for 1 (2:1) or inhaling for 3 steps and exhaling for 2 (3:2).
This seems to be a logical pattern of breathing when running. First of all, it is good practice to breathe in sync with your footfalls. When breathing with your footfalls, you time the movement of your body and internal organs with the movement of your diaphragm during respiration. This prevents the development of odd, uncomfortable areas of pressure on the diaphragm which can impede breathing. In terms of the speed of breathing, the more quickly you breathe, the less time your body has to fully absorb the O2 you’re bringing in through respiration. When your body doesn’t have enough oxygen to energize itself, anaerobic metabolism kicks in, which causes lactate to accumulate and decreases the body’s ability to perform endurance tasks. However, when you breathe slowly, more oxygen is drawn into the body, and the body has enough time to absorb the oxygen in your lungs to create energy and keep you energized when running.
Therefore, by slowly breathing in a 3:2 or 2:1 pattern in sync to your footfalls when you run, you have the potential to run more smoothly and for a longer period of time before fatiguing by maximizing oxygen uptake.
While there is no standard convention for breathing when running, there is one near-universally accepted standard of breathing for weight lifting exercises. Convention says that while performing weight lifting tasks, one should exhale on exertion and inhale during reset. Easy enough to remember, right? But, is this the best way to breathe when lifting weights?
Studies point to yes. In one study by Hagins, et al. subjects were asked to perform three different breathing patterns while lifting objects:
While subjects were doing this, measurements were being taken of change in abdominal pressure and maximum force exerted. These measurements showed that abdominal pressure was lowest during breathing patterns 2 and 3, both of which involved exhalation.
Another study by Lamberg and Hagins looked at breathing patterns when lifting different loads. Subjects were asked to lift milk crates multiple times while a pneumotachograph recorded airflow. This study found that the most consistent natural breathing pattern among individuals was to inhale right before lifting an object, which is consistent with the results of the previous study.
Based on these two studies, it is clear that exhalation is an important part of breathing during weight lifting. By reducing the amount of pressure in the abdomen, exhaling during lifting decreases the chances of sustaining internal injuries such as hernias and vessel strains which can be caused by excessive internal pressure. Exhaling relieves that pressure by releasing some of the accumulated air from the abdomen, ensuring that the abdominal pressure does not reach an unsafe level. So, next time you go to the gym to bench press, remember to exhale when pressing and inhale before letting the weight down onto your chest to regulate pressure build-up in your chest and abdomen.
The studies viewed in the cases of running and weight-lifting were limited in that they consider only two very rigidly structured types of exercise. The running study had subjects running at specifically selected speeds. And, the weight-lifting studies only looked at subjects lifting specific weights in an up-down direction. But, what about sports where running speed and timing can vary, such as soccer or football? Or exercises where full-body balance is the goal, such as yoga? Is there an optimal breathing pattern for these sports and exercises?
More testing needs to be done to determine optimal breathing for these sports. But, based on the results of existing studies and on common practice in sports, it’s likely that the best breathing pattern for your sport will involve a balance between maximizing oxygen uptake and regulating abdominal pressure.
For more information about breathing during exercise, explore: