Michael Mosley's Exercise, My Exercise

After watching “The Truth About Exercise” I wanted to find out more about Michael Mosley.  He is a writer, doctor, and producer and presenter of TV programs and he has been interested in getting into better shape for several years.  About five years ago, after turning fifty and assessing his situation, he tried a restricted calorie diet and human growth hormone shots.  Neither approach was a success.  “The Truth About Exercise” chronicled more recent efforts and this year there is a book, The Fast Diet, that recommends eating your typical diet five days per week and one-quarter that number of calories (about 500 or 600) two days per week.  Apparently this worked for Mosley, as we will be able to see on an upcoming three part series on PBS.

In “The Truth About Exercise” Mosley applied new ideas about exercise to his own situation.  While watching the show, I mentally compared his experience with what has happened to me as I have tried to lose weight and improve my fitness over the years.  Michael Mosley and I have some things in common: we both like wine, chocolate, and good food.  Neither of us is especially fond of exercise.  In other ways, though, we are opposites.  Mosley is a toffee.  He looks lean but he has visceral fat around his internal organs.  I have never looked lean (and probably never will because I’m so muscular) but my visceral fat is not high, 9 or 10 on the Tanita Ironman’s scale of 1-60.  

When Mosley visits Dr. Emma Ross he learns that his brain is actually keeping him from exercising as much as he is physically capable of doing.  Something like this happened to me about four years ago.  I had been doing interval training and working up to faster speeds on the cross trainer but I was starting to feel that it was too much, getting a little tired and light-headed, especially on hot days during the summer.  What got me past this obstacle was the metabolic training program I did with Greg and Susan Simmons. 

I exercised with a mask over my face that allowed Greg and Susan to monitor how my body was burning carbs and fat.  Based on my (very slow) metabolism, they designed an exercise program that would increase my aerobic base so that my body would become better at burning fat.  After that, we worked to increase my anaerobic threshold so that I could exercise at a higher intensity.  The workouts for this program were long and boring at first but I ended up being able to do a shorter, harder workout without feeling overstressed.  These days the aerobic part of my workout consists of a 33-minute series of intervals with heart rate averaging in the low 130’s, about 85% of maximum heart rate for me.  I do this routine twice a week. As part of the program Greg and Susan tested my VO₂max, a measure of cardiovascular fitness.  It was a not-bad 39 and got up to 42.9 the last time they tested it.  Mosley’s was a not-bad 37 but didn’t change at all as a result of the HIT training he did.

Michael Mosley seems especially interested in reaching the 80% of people who never go to the gym.  The segment with Dr. James Levine emphasizes the importance of non-exercise activity thermogenesis (NEAT) and encourages people to walk, ride a bike, and take the stairs in order to burn more calories during the day.  For people who rarely get up and move around during the day this approach may really help, but for people who are already somewhat active it may not make enough of a difference.  At our house we doing our own cooking, cleaning, laundry, and most of the yard work but we still have to watch what we eat and go to the Y in order to keep from putting on weight!

Interval training has been the subject of a lot of research lately.  It seems to be pretty well established that interval workouts are more efficient and effective that long, steady cardio sessions.  What is less clear is exactly how the intervals should be done and whether this is the same for everyone.  HIT, per Professor Jamie Timmons, involves very short intervals of 20-30 seconds.  I tried short-interval workouts for a while and saw no improvement at all; I didn’t lose weight and my fitness didn’t improve.  I was in decent shape so my resting heart rate was low (50 bpm or so).  To raise my heart rate to the point where I was actually working (at least 120) took more than 20 seconds – the interval was over before it had even started.  When I did the resting part my heart rate would go right back down to 70 or so and still not get much above 120 on the next round.  For my present regimen, I warm up for five minutes to get my heart rate to the mid-120’s, which is a good starting point.  I then alternate intervals of four and three minutes at 125-130 bpm and 135-140 bpm, respectively, for an overall average of about 132 bpm.  The 33-minute workout I do burns 300 calories or less, according to my Polar heart rate monitor.  For my body, a 12-minute workout would probably have no effect at all.  

It’s great that HIT improved Mosley’s insulin sensitivity but I sometimes felt that both he and Timmons verged on saying that the 12-minute routine might be all the exercise a person needs.  Leaving aside the issue of what cardio is right for each person, there are many types of exercise that can improve the body in many different areas, including strength, agility, quickness, flexibility, and balance.  While encouraging non-exercisers to exercise is a thoroughly admirable goal, it is also important to encourage those who do a little to try to expand the range of what they can do and improve their condition even more.  

I wish the segments about HIT had included information about Mosley’s resting heart rate and whether that changed as a result of the HIT training.  Resting heart rate is an important index of fitness.  I try to keep mine in the 45-50 bpm range and I do the cardio intervals mostly for that purpose.  If I go on a trip and don’t work out for a couple of weeks it tends to creep back up but after a few workouts it comes right back down.  A recent Danish study showing that healthy men with a resting heart rate of 51-80 bpm had a 40-50% greater risk of death than those at or below 50 bpm.  At 81-90 bpm the risk was doubled and above 90 bpm it was tripled!