Single vs Double Leg Jumps

Plyometrics are explosive workouts aimed to improve power and burst force. These types of exercises are typically given to athletes in sports that require quick power or movement. Plyometrics for athletes are used to improve an athlete’s Rate of Force Development (RFD). The RFD is essentially how quickly an athlete can load up (i.e contract) their muscle for use. For explosive power, you are looking at muscle loading taking place within 250 milliseconds.

Previous studies have reviewed strength generated between one leg and both leg activiations. The  findings determined that one legged exercises produced more strength in that leg than the same  exercises done with both legs. These studies were solely done on strength moves and not explosive  moves.

A study was done at the University of Athens to specifically look at explosive power between single  and double leg exercises. The study used 15 physically active participants between the ages of 18  and 26. All participants completed a test on single leg jumping and double legged jumping before and after the study. Participants were split into two groups, one for single leg and one for double leg  exercises. Each group completed 8 exercises twice a week for 6 weeks.

After the 6 week training session the participants all completed the same single leg and double leg  jumps as they did at the start.

Figure 1 shows the initial results for each group and the percent change for each group at the end of the study. The white bars are the bilateral or the double leg group. The black bars are the unilateral or single leg group. The first graph shows the average results for each jump and each group followed by the percent increase for each jump and each group. Both groups saw a similar increase in their double legged jump performance. However, the single leg group saw a 15.6% larger improvement for the single leg jumps on average, which is 5 times more improvement!

Figure 1: Post study testing results

These results can conclude that single leg plyometrics is great for increasing single leg jump  performance as well as double leg jump performance. Double leg plyometrics is great for increasing  double leg jump performance, but less effective at improving single leg jump performance.

A possible explanation for the greater improvement in single leg jumps is due to the nature of the  movement. It has been observed that single leg movements are slower than double leg movements.  The slower speed allows more of the muscle to contract, which leads to a greater force during the  movement. This could explain why the single leg group performed better in the single leg jump test,  since they were training more of the maximum force in their legs.

The take away from this study is that athletes should be incorporating single leg plyometrics in their  training to improve lower body explosive power.



References

https://journals.lww.com/nsca-jscr/Fulltext/2019/03000/Comparison_Between_Unilateral_and_Bilateral.5.aspx

https://www.scienceforsport.com/rate-of-force-development-rfd-2/

Small Dietary Changes to Help Weight Loss

Wanting to make changes to your regular diet can be overwhelming and difficult to maintain. Tracking calories takes a lot of work and constant vigilance. Since new diets are popping up all the time, knowing which one is right for you takes research and some trial and error. A diet that changes drastically from what you are currently doing can quickly become unsustainable, especially if it requires more prep time than you are used to. As with any major life change, it’s best to start small and sustainable. Here are four small changes to your diet can you make now as you transition to a healthier lifestyle.

1. Drink More Water

I think the easiest change you can make to your day is to drink more water. Drinking water in general is good for your body since it helps rejuvenate your cells, so this is just another reason to add on to the list. A study done in 2015 found that people who drink two glasses of water 30 minutes before a meal lost more weight on average than those who didn’t. The hypothesis is that the water expands your stomach, making you feel full. So if you think you are overeating at meals, give this a try to help reduce food intake.

2. Cut Back on Snacking

Snacking is often thought of a good way to curb hunger throughout the day and reduce calories eaten at major meals, but science does not back this idea. If you aren’t into calorie tracking, snacking can increase your overall calorie intake, rather than decreasing it. If you are feeling hungry, it’s best to eat a full meal. A small snack will not fill you up, and you may be just as hungry when you do eat a meal. Additionally, snacking has become a social event or something done out of boredom when you aren’t even hungry. Many studies have been done over the years linking the removal or reduction of snacking to weight loss for obese people.

3. Watch out for Branding!

People wanting to live a healthy lifestyle are more likely to purchase foods that have wording on the packages associated with health and fitness. Subconsciously people feel better about their food choice and end up eating more and exercising less. A study at the University of Texas examined the amount of a food people ate to the branding. The study found that people were more likely to eat up to twice as much of a healthy branded food than an unbranded food. Your best bet is to review the ingredients, nutrition information and the serving size, rather than the packaging of foods.

4. Do you Have a Sweet Tooth?

Don’t worry, you can still satisfy that craving while maintaining your healthy lifestyle. Keep some dark chocolate (70% cocoa or higher) in the house. When you have a craving during the day eat a square, but keep it to two squares a day. Dark chocolate is sweet enough to satisfy that craving, and may also satisfy salty snack cravings. In addition, dark chocolate has a surprising amount of micronutrients (vitamins and minerals) important to your diet, as well as a good amount of antioxidants, which help reduce the amount of free radicals in your body.

The above are just four changes you can make to your diet in a small way, there are many more, such as serving food on a smaller plate to force smaller portions, keeping snack food off the counter and out of sight, and eating more calories early in the day rather than later. When choosing what kind of changes to make review your current routine and pick changes that you can easily add into your day.

References

https://www.ideafit.com/fitness-library/the-science-of-eating-better

http://www.healthline.com/nutrition/7-health-benefits-dark-chocolate#section3

What is Metabolism?

People are always commenting on their metabolism. That it’s great, bad, fast, slow or even supercharged . But what does it actually mean? What is your metabolism, what affects it, and how can you use this information to make the most of your training?

The scientific definition of metabolism is the chemical processes taking place inside of your cells. Metabolism is your cells repairing, growing, reproducing, and everything else they require to live. Metabolism is the total of both energy added and energy used. You can think of it as your net cellular energy. Energy is constantly being used and created in your body, so it’s difficult to actually change your metabolism. Check the first reference if you want more detail into exactly what it is your cells are doing.

Typically, apart from medical conditions, you can’t speed up your metabolism. Our cells function at a set rate, you can’t make them repair any faster. Fortunately, there are a few things you can do to help your metabolism function at a high capacity. Below are a few starting examples to consider when maximizing your training. For more steps you can do, read the third article referenced.

Contrary to how it sounds, one way that can slow your weight loss is to not eat enough.. If you are trying to lose weight, you do want to cut down your calories so you burn more energy from your body than you consume. However, if you cut out too many calories, your body will go into starvation mode. In starvation mode your metabolism actually decreases by not using as much energy as it normally would. Basically your body is working to keep you alive longer, so it is rationing energy.

The second thing you want to do is have consistent mealtimes. Not eating at regular times puts your body into a cycle of mini starvation modes, again conserving energy in case you don’t get more energy soon. This isn’t saying you need to eat at 12:00 pm exactly everyday. You just don’t want to have massively fluctuating hours between meals. For example one day you eat meals 3 hours apart and the next you have to skip lunch and it becomes 8 hours between eating. Whatever spacing of your meals you prefer is good, just keep it consistent so your body adjusts and can build a routine.

One of the most impactful ways you can improve your metabolism is to, make sure you are strength training regularly. Target about two times a week if you are just starting out. Strength training causes micro-tears in your muscle, which need to be repaired. Repairing muscle builds them stronger and takes energy. See where I’m going here? By strength training, you are giving your body more to work on than normal. Also, sustaining muscle mass burns more energy compared to fat or lean mass, so you are passively increasing your calorie burn 24/7. .

As you age, your metabolism drops. The reasons for decreased metabolism with age is linked to a decreased muscle mass. As we age we lose muscles gradually, to counter this make sure you keep strength training. But even a decrease in activity and strength training doesn’t fully cover the decreased metabolism age brings. It’s not entirely clear yet why, but speculation is that there is a decrease of metabolic activity in your organs. Whatever the reason, make sure you are constantly working towards a healthy you in all aspects of your life!

References

http://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/metabolism/art-20046508?pg=1

http://comfortpit.com/what-is-metabolism/

https://www.acefitness.org/acefit/healthy-living-article/60/6090/8-things-that-slow-down-your-metabolism/

https://www.acefitness.org/acefit/healthy-living-article/59/2315/is-it-true-that-metabolism-decreases-with-age/