Newsletter Article

MVPA for Good Health

September 2016

Moderate to vigorous physical activity (MVPA) is a category of activity intensity that has been consistently shown to benefit and/or reduce the risk of many chronic disease states. MVPA is measured with Metabolic Equivalents (METs).[1] A MET is the ratio of a person’s working metabolic rate compared to their resting metabolic rate. A person sitting quietly would be considered 1 MET. Moderate-intensity physical activity is defined as 3 – 6 Metabolic Equivalents (METs) and Vigorous-intensity physical activity is defined as any activity above 6 METs. This means that MVPA is any activity over 3 METs.

An analysis of data collected from the U.S. National Health and Nutrition Examination Survey (NHANES) showed a link between MVPA time, sedentary time, and all-cause mortality.[2] Both MVPA and sedentary time were independently associated with all-cause mortality. Researchers found that sedentary time was not associated with all-cause mortality if a person spent more than the median time in MVPA. However, sedentary time did increase risk in those who spent less than the median time in MVPA. These findings suggest that increased MVPA time may counteract sedentary behaviors over long periods of time.

Another study came to similar conclusions about benefits of MVPA.[3] Compared to subjects who did not meet activity guidelines (0-1999 MVPA MET-min-month), a dose-response relationship was seen with MVPA time and mortality. The subjects with the lowest risk were those participating in 5 times the guideline level. They did not find any harmful effects for those that participated in very high levels of MVPA (20,000+ MVPA MET-min-month).

Current recommendations suggest that MVPA activities should last greater than 10 minutes at a time.[4] A study examined MVPA measurements, 5 years apart, to determine the effect on hypertension and obesity. Any MVPA time under 10 minutes was considered a short spurt of MVPA. Subjects that were in the top tertile for recorded short spurts were 31% less likely to develop hypertension compared to those in the lowest tertile. There was no association with obesity, but this helps to show that even short periods of MVPA can produce health benefits.

MVPA can play a major role in overall health. Meeting the recommended guidelines is important, but even shorter bursts of this type of activity can provide some protective factors.

Pears

Pears are a member of the Rosaceae family of plants, which also includes roses, apples, apricots, cherries, peaches, plums, and strawberries.[5] China is the largest producer of pears by far, growing nearly three quarters of the 21 million tons produced worldwide each year.

Pears are rich in antioxidants, but the skin in particular has up to 3-4 times the amount of phenolic phytonutrients as the flesh. The skin also contains approximately half of the fruits’ dietary fiber. Some of these antioxidants may be key to helping reduce the risk of type 2 diabetes by improving insulin sensitivity.[6] Among all combinations of fruits and vegetables, the combination of apples and pears most consistently demonstrated the ability to lower the risk of type 2 diabetes due to their specific antioxidant profiles and fiber content.

Pears may also help reduce the risk for heart disease. Researchers have found that pear fibers bind to bile acids in the lower intestines, which can slow down the synthesis of cholesterol. These fibers can also bind to what are called secondary bile acids. High amounts of secondary bile acids can increase the risk of developing colorectal cancer and other intestinal problems.

Pears are a low acidity fruit and easily digested. They are also considered to be a low allergy food, so many healthcare practitioners include pears in low-allergy diet plans. For these reasons, as well as their widespread availability, pears can be eaten by most people around the world. And when you consider their high phytonutrient and fiber content, pears are a fruit that should be a part of every person’s diet.

Arugula and Pear Salad

Ingredients:
1/2 cup walnut halves
5 to 6 cups arugula, washed and dried
1 Bosc or Anjou pear, thinly sliced
1 lemon
3 tbsp extra-virgin olive oil, eyeball it
Salt and freshly ground black pepper
8 oz. Gorgonzola or blue cheese crumbles

Directions:
Toast nuts in small pan over medium heat until fragrant. Cool. Combine arugula and pear in a salad bowl, add nuts then dress the salad with lemon juice and olive oil, salt and pepper. Top salad with lots of blue cheese crumbles.

Recipe from http://www.foodnetwork.com/recipes/rachael-ray/arugula-and-pear-salad-recipe.html/

Hydration

During an athletic competition, hydration is vital for optimal performance. Hockey players studied during a practice were either given a carbohydrate and electrolyte solution (CES) or no fluids were allowed.[7] Researchers found the CES group had a lower core body temperature, skated a greater distance and at greater speed during the middle of practice, and committed fewer puck turnovers at the end of practice. The CES group had significantly less body weight loss and almost no change in body mass, while the group with no fluids had an almost 2% body mass decrease. These findings demonstrate how fluid intake affected almost every aspect of these players practice.

Hydration strategies may differ between coaches and programs in terms of how much an athlete should drink. A study compared runners who were assigned to an ad libitum group (AL) or an individualized rehydration group (IR).[8] The AL group experienced a 2.6% body mass loss while the IR group experienced a 1.3% body mass loss. There was a time interaction with condition and HR, but there were no significant differences in body temperature or performance between groups. This was a 20-km trail race using well-trained runners. Less experienced runners or a greater running distance may have different results.

Hydration may play a more important role in sports that are more fast-paced and involve more coordination. The type of hydration may play a factor, but any type of hydration is more beneficial than not taking in any fluids.

Health Matters is written by Lindsey Guthrie, MS, RD, LD/N and Tyler Guthrie, MS, CSCS.

References:

  1. World Health Organization. What is Moderate-intensity and Vigorous-intensity Physical Activity? http://www.who.int/dietphysicalactivity/physical_activity_intensity/en/
  2. Loprinzi PD, Loenneke JP, Ahmed HM, Blaha MJ. Joint effects of objectively-measured sedentary time and physical activity on all-cause mortality. Preventive Medicine. 2016; 90: 47.
  3. Loprinzi PD. Dose–response association of moderate-to-vigorous physical activity with cardiovascular biomarkers and all-cause mortality: considerations by individual sports, exercise and recreational physical activities. Preventive Medicine. 2015; 81: 73.
  4. White DK, Gabriel KP, Kim Y, Lewis CE, Sternfeld B. Do Short Spurts of Physical Activity Benefit Cardiovascular Health? The CARDIA Study. Medicine and Science in Sports and Exercise. 2015; 47(11): 2353.
  5. The George Mateljan Foundation. Pears.http://www.whfoods.com/genpage.php?tname=foodspice&dbid=28
  6. Wedick NM, Pan A, Cassidy A et al. Dietary flavonoid intakes and risk of type 2 diabetes in US men and women. American Journal of Clinical Nutrition. 2012; 95(4): 925.
  7. Linseman ME, Palmer MS, Sprenger HM, Spriet LL. Maintaining hydration with a carbohydrate–electrolyte solution improves performance, thermoregulation, and fatigue during an ice hockey. Applied Physiology, Nutrition, and Metabolism. 2014; 39(11): 1214.
  8. Lopez RM, Casa DJ, Jensen KA, et al. Comparison of two fluid replacement protocols during a 20-km trail running race in the heat. Journal of Strength and Conditioning Research. 2016; 30(9): 2609.

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