What is the Best Workout Program for Improving Health According to Research?

Are you working out regularly and not seeing results?  It’s possible to be spinning your wheels, going to the gym diligently, without getting the changes you were hoping for.  No worries, I’m about to give you the scoop on what may be going wrong.  And, what researchers say may be the best workout program for improving your overall health.

We all know being committed to a regular exercise program will improve the quality of our lives in many ways.  But not all workout programs are created equal.  In other words, some workout programs simply deliver way more health benefits than others.   Such as, greater improvements in cardiorespiratory fitness, cholesterol levels, blood pressure, insulin sensitivity and even faster weight loss.


The question is, does your routine affect the nitty gritty details of your health?  For example, when you get your physical each year, are you seeing better than average numbers for your blood pressure, trigylcerides, HDL and blood sugar?  Are you in your ideal weight range and keeping your waistline trim?


If you are working out regularly but your bloodwork numbers aren’t budging or worse, gradually going the wrong way, you may be wondering why your diligence isn’t paying off.  So what gives?  Assuming your diet is under control and you don’t have other health issues that may affect these outcomes, it could be your exercise routine needs a closer look.


Which brings me to a new study that demonstrates the importance of being on a personalized workout program when you want to see significant results.  It’s no surprise that everybody is different and therefore the more customized a program is, the more effective it will be.


The American Council on Exercise, (ACE), a nonprofit organization and a leading certifying body for fitness professionals, wanted to take a deep dive into this.  They set out to compare their personalized program known as, “Integrated Fitness Training” to an industry standard program for cardio respiratory fitness (CRF).  The Integrated Fitness Training model is a combination of moderate intensity cardio training, high intensity interval training and weight training.


ACE enlisted the help of Lance Dalleck, PhD, and his exercise research team at Western Colorado University.  I recently had the opportunity to speak with Dr. Cedric Bryant, Chief Medical Officer for ACE, about the study.


Some background:


Research has already established that HIIT (high intensity interval training) significantly increases cardiorespiratory fitness (CRF) by almost double that of MICT (moderate intensity continuous training) in people with lifestyle-induced chronic diseases.


For the new study, the researchers were tasked with comparing the difference between doing an exclusively MICT program versus a HIIT plus MICT program over 13 weeks.  “Think of someone who gets on a cardio machine at the gym and stays at one level for 45 minutes,” says Bryant.  They may break a sweat, but they don’t get too out of breath and can carry on a conversation with the person next to them.”  That’s MICT.  Or as we sometimes refer to it:  steady state cardio.


How they tested it:


For this 13-week study, the researchers divided 54 volunteers (men and women between the ages of 21 ñ 55 who do little to no regular exercise) into one of three groups:  A control group who didn’t exercise, an MICT + HIIT group using an individualized program and, an MICT only group. 


“One of the main differences between the two exercise groups was how they utilized heart rate,” says Dr. Bryant. The MICT group’s exercise intensity was based on a percentage of their heart rate reserve (HRR).  This number is derived from a formula based on age and resting heart rate.  The MICT + HIIT group based their exercise intensity on each individuals ventilatory threshold (VT).


MICT vs HIIT + MICT study

the training programs

Back up, what’s Ventilatory Threshold?


VT is a way of measuring exercise intensity based on how hard you’re breathing.  There are two ventilatory thresholds.  VT1 and VT2.


VT1 is the first ventilatory threshold. It’s where you’re breathing to the point where lactate begins to accumulate in the blood and so you start to breathe faster.  At VT1, you can no longer talk comfortably, but you can still blurt out short, breathy sentences.


VT2 is the second ventilatory threshold. This is where lactate has quickly accumulated in the blood (feeling some burn) and you’re breathing hard.  At this intensity, you can can’t talk or last much longer.  You may have heard this is referred to as your “anaerobic threshold,” or “lactate threshold.”  Now you can nerd-out and toss these phrases around next time you’re working out with your friends.


OK, back to the study.


What did the programs look like?


Both groups started off with 3 day a week programs for 30-minutes.  The programs gradually increased in intensity, duration and up to 5 days a week.  In week 4, both exercise groups started adding in resistance training.


The cardio only, MICT workouts were done on common machines like rowing, arm and cycle ergometers, elliptical cross-trainers and treadmills.


Remember, the intensity for the MICT only group was based on hitting certain heart rates, which is a standard exercise programming approach.


The MICT + HIIT group had their programs based on each persons’ VT and, one of their workouts each week was a HIIT.  Each HIIT session consisted of eight 60-second intervals performed at 100% VO2max with 2.5 minutes of active recovery in between.  VO2max is the maximum amount of oxygen the body can use during intense exercise.  It needs to be tested using special equipment but there are some equations that can estimate VO2max.


Starting at week 5, the number of HIIT intervals gradually increased from 8 to 12. The active recovery stayed the same.


Their personalized group’s cardio workouts looked like this:


Weeks 1 – 4, heart rate range 10-15 bpm below VT1

Weeks 5 – 8, heart rate range 10–20 bpm above VT1 and below VT2

Weeks 9 – 13, heart rate range 10–15 bpm at or just above VT2


The MICT only group performed their cardio exercises with heart rates starting at 40% HRR and worked up to 65% HRR.


Both groups did 3 strength workouts a week starting at week 4.  They each performed 2 sets of 12 reps of each exercise and gradually increased in weight every 2 weeks.


The MICT only group did a standard strength training routine which included exercises like bench presses, lateral pull downs, biceps curls, etc. hitting all major muscle groups.


The strength training routine for the personalized group performed exercises that allowed more free motion like lunges, wood chops, one arm rows, etc.


What were the results?


The interesting thing about this study, which was unusual, was it measured the participants’ MetS z-score.  What’s that?  The MetS z-score is the metabolic syndrome severity score.  It’s used to predict the risk of someone developing metabolic syndrome.  People with the metabolic syndrome are at higher risk for heart attack and cardiovascular disease.  They are more likely to have a stroke, develop diabetes and fatty liver disease.


The big finding in this study was that 100% of  the participants in the personalized MICT + HIIT group had a reduction in the MetS z-score.  Pretty awesome!  But only a little more than half (56.25%) of the people in the MICT only group saw a favorable change in MetS z-score. That means 43.75% (7 out of 16) participants saw no change or an undesirable change in the MetS z-score.  These folks are referred to as “nonresponders” to exercise training.   As I mentioned in the beginning, it’s possible to be spinning your wheels at the gym, going diligently and not seeing any real health benefits.



Changes in VO2max were also tested.  This is the usual metric used for these types of cardiovascular fitness studies.   The results showed more good news for MICT+HIIT group as100% of the participants saw improvements.  Whereas only 68.75% of the MICT-only group responded positively to their training.


What’s the takeaway?


If you work out regularly, you want to see improvements in your cardiovascular fitness and your other health biomarkers.  At the very least, you don’t want to be getting worse.  Of course, diet is one factor.  A mantra in the fitness training world is, “you can’t out-train a bad diet.”  Assuming you’re on a healthy eating plan or working with a nutrition coach who’s helping you get there, your workout program should have a positive effect on your health.  If not, it may be time to hire a trainer or a coach who’s familiar with designing programs like the one studied.


Trainers are not just for newbies.  They can help design a program tailored to your needs, keep  you on course and help to keep you improving.


Thinking about a career  where you make a positive difference in peoples’ lives?  If you’re thinking about becoming a Certified Personal Trainer or Group Fitness Instructor, check out ACE.

Click here for general ACE info.


These 2 are for free career guides for anyone thinking about a new career in fitness:

FREE ACE Personal Trainer Career Guide

FREE ACE Group Fitness Instructor Career Guide

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Jill Brown
Jill Brown
Hi, I'm JillI am a Los Angeles based Fitness + Nutrition Coach. With 20+ years of experience in teaching, training and continuing my education, I have transformed thousands of lives through fitness and healthy lifestyle changes.