I’m sure you’ve heard multiple recommendations on what type of exercise provides more health benefits.
Recently published data showed that moderate-to-vigorous physical activity resulted in:
- improved insulin resistance
- greater weight loss
- smaller waist circumference
- better fasting insulin
- lower 2-hour glucose
- decrease in triglycerides
- improvement in C-reactive protein (CRP), which serves as a cardiovascular risk factor for developing heart disease and eventually a heart attack
- higher testosterone 
Another study showed that 20-minute daily sessions of high intensity interval training (HIIT) for 6 weeks dramatically improves performance in memory. 
The latest benefit that was just uncovered: exercise can have an effect on your gut, independent of diet or other factors. Fecal concentrations of short chain fatty acids (SCFA), in particular butyrate, went up in the human gut, as a result of exercise.
Butyrate is vital to our well-being, because a high level of butyrate is associated with:
- colon cancer prevention
- benefits for our intestine lining, as a main source of nutrition for cells and support healthy gut barrier function
- improvement in fatty liver
- immuno-regulation, by suppressing inflammation in the intestines
- improvement for autoimmune disorders like Rheumatoid arthritis, lupus
- greater weight loss
- decreased insulin resistance, helps with diabetes and decreased cholesterol
- reduced risk of stroke, hearing loss and dementia
- even improvement in autism, depression and anxiety. 
Unfortunately butyrate levels quickly declined again, after participants reverted to a sedentary lifestyle. Genetic tests of the microbiota confirmed that this corresponded to changes in the proportion of microbes that produce butyrate and other SCFAs. 
So let’s look again at HIIT.
HIIT intense work periods may range from 5 seconds to 8 minutes long, and are performed at 80% to 95% of a person’s estimated maximal heart rate, the maximum number of times your heart will beat in a minute without overexerting yourself. The recovery periods may last equally as long as the work periods and are usually performed at 40% to 50% of a person’s estimated maximal heart rate. The workout continues with alternating work and relief periods totaling 20 to 60 minutes.
HIIT training can easily be modified for people of all fitness levels and special conditions, such as being overweight and having diabetes.
HIIT workouts can be performed on all exercise modes, including cycling, walking, swimming, aqua training, elliptical cross-training, and in many group exercise classes.
HIIT workouts provide similar fitness benefits as continuous endurance workouts, but in shorter periods of time.
This is because HIIT workouts tend to burn more calories than traditional workouts, especially after the workout. The post-exercise period is called “EPOC”, which stands for excess post-exercise oxygen consumption. This is generally about a 2-hour period after an exercise bout, where the body is restoring itself to pre-exercise levels, and thus using more energy. Because of the vigorous contractile nature of HIIT workouts, the EPOC generally tends to be somewhat greater, adding about 6% to 15% more calories to the overall workout energy expenditure. This is why you should try to do HIIT in the morning – to prevent insomnia at night and to give yourself a jump-start energy boost at the beginning of the day.
When developing a HIIT program, consider the duration, intensity, and frequency of the workout intervals and the length of the recovery intervals. Intensity during the high “work” intervals should be greater than 80% of your estimated maximal heart rate. As a good subjective indicator, the high interval should feel like you are exercising “hard” to “very hard”. Using the talk test as your guide, it would be like carrying on a conversation with difficulty. The intensity of the recovery “low” interval should be 40-50% of your estimated maximal heart rate. This would be a physical activity that felt very comfortable, in order to help you recover and prepare for your next “high” interval. 
HIIT workouts are extremely cost effective, because you need zero equipment! They can be done in the comfort of your home.
All you need is a little open space. HIIT workouts utilize your own body weight, so any workout that gets your heart rate up quickly such as plyometrics, high knees and jumping jacks can be implemented into a HIIT workout. In fact, weights can actually make the workout less effective, because the main focus in HIIT is getting your heart rate up, rather than toning a particular muscle group.
Before you start any exercise program, please schedule an appointment with your primary care doctor to discuss you level of health. Dr. Koganski is available at 215-750-7000 or www.NewtownInternalMedicine.com.
 Swindell N, et al. Objectively Measured Physical Activity and Sedentary Time Are Associated With Cardiometabolic Risk Factors in Adults With Prediabetes: The PREVIEW Study [published online 20, 2017]. Diabetes Care. https://doi.org/10.2337/dc17-1057.
 Jennifer J. et al.The Effects of Physical Exercise and Cognitive Training on Memory and Neurotrophic Factors. Journal of Cognitive Neuroscience Volume 29 | Issue 11 | November 2017 p.1895-1907. doi: 10.1162/jocn_a_01164.
 Roberto B Canani,et al Potential beneficial effects of butyrate in intestinal and extraintestinal diseases. World J Gastroenterol. 2011 Mar 28; 17(12): 1519–1528. Published online 2011 Mar 28. doi: 10.3748/wjg.v17.i12.1519PMCID: PMC3070119.
 Exercise alters gut microbiota composition and function in lean and obese humans” . U. of I. News Bureau. DOI: 10.1249/MSS.0000000000001495.
benefits of exercise
short chain fatty acids