Tuesday, May 12, 2015

Which Cardio Machine Should I Buy?

Getting to the gym on a daily basis doesn’t really work long term. We are all just too busy. Having the ability to do cardio at home is pivotal to generating the type of consistency necessary to make lasting changes to your weight.

A question I always get is; “What cardio machine should I buy?” My answer, in every case, is an elliptical trainer.

1) Elliptical trainers are low impact. Many modes of cardio that burn a lot of calories are tough on your joints. High impact cardio classes and running are two examples. Elliptical trainers are much easier on your joints. My client’s that use elliptical trainers have far fewer injuries than those that engage in more impactful forms of exercise.

2) You burn a lot of calories. Since elliptical trainers are an upright form of exercise, you lift your full body weight with each repetition. This makes the elliptical machine an efficient calorie burner.

3) Elliptical trainers are appropriate for all fitness levels. If you are young, fit, and work out with a bit more intensity, you can get a high-end, gym quality elliptical trainer like a Life Fitness model. These will have all sorts of variety in resistance, fitness programs, and other bells and whistles. If you are older or a little less fit, you can get a glider like the Gazelle Edge, which has no resistance and simulates walking.

4) Elliptical trainers can fit any budget. If you want to spend several thousand dollars on a gym quality machine for your home gym, there are lots of options that are worth every penny. If money is tight, you can get a glider, like the Gazelle Edge, for $130, which will do the job nicely.

Beverages and Weight Gain

The Study
The long term association beverage choice and weight gain was examined in a combined cohort of the Nurses’ Health Study, The Nurses’ Health Study II, and the Health Professional Follow-up Study. In total, there were 124,988 subjects included in this investigation that were followed for approximately 20 years. Participants reported their beverage consumption and their weight every 4 years throughout the study period. The researchers then calculated how 1 daily cup of a given beverage would impact weight each 4 year period. 

Here are the results:
1 cup of water resulted in .3 lbs. of weight loss

1 cup of sugar sweetened beverages resulted in a .8 lbs. weight gain

1 cup of fruit juice resulted in a .5 lbs. weight gain

1 cup of diet soda resulted in .2 lbs. of weight loss

1 cup of coffee resulted in .3 lbs. of weight loss

1 cup of tea resulted in .1 lbs. of weight loss

Substituting 1 cup of water per day for 1 cup of sugar sweetened beverages resulted in a weight loss of 1.1 lbs. over 4 years.
International Journal of Obesity 2013; 37:1378-85.

Take Home Message
At first glance these numbers seem kind of small. However, it is important to realize that these results are for just one cup. Many of us drink 20 ounce sodas and coffees. If you drink 8 glasses of water per day, 8 x .3 = 2.4 lbs. of weight loss over 4 years, 4.8 lbs. over 8 years, 7.2 over 12 years and 9.6 over 16. My point is that these numbers can add up over time to have a powerful impact on your weight.

It is becoming evident that the body does not fully recognize calories in liquid form. In other words, if you have a snack before dinner, most of us will eat a bit less at that dinner to compensate. Studies show that if you drink a soda before dinner, you won’t eat any less at the meal. Liquid calories don’t seem to register with our body the way solid food does.

Stay away from calorie containing beverages like soda and fruit juice, and instead go for water, club soda, coffee, tea and the occasional diet soda. Over time, these choices can have a really nice impact on your weight and your health.


Can you be obese, yet totally healthy?

The Study
The idea that it is possible to be obese yet healthy has been bounced around for some time. This hypothesis was tested in an investigation of the Whitehall II cohort of British government workers. In this cohort of 2,521 men and women, 66 met the criteria for being obese (BMI ≥30) and healthy (<2 of the following metabolic symptoms: low HDL cholesterol, high blood pressure, high fasting glucose, high triglycerides, insulin resistance). After 20 years of follow up, more than half of the healthy obese subjects progressed to unhealthy obesity. Furthermore, after 20 years, the healthy obese in this cohort were nearly 8 times more likely to progress to an unhealthy obese state than the healthy non-obese adults. Journal of the American College of Cardiology 2015; 65:101-02.

Take Home Message
This study presents convincing evidence that if you are obese but currently healthy, there is a good chance that you won’t be for long. If your BMI is 30 or greater, get it below 25, even if you are free of metabolic symptoms.

Feature Article: Can you exercise too much?

There has been a major push in the last few years towards extreme fitness. The trend right now is to exercise to the absolute limit of your abilities. People are flocking to boot camps and intense interval cardio classes. Every year, more people run marathons and take part in other extreme endurance events like bike races and “survival” obstacle course races. 

I am generally a big fan of fitness fads. Anything that gets people excited to work out is cool with me. However, this really high intensity training trend has always made me a bit nervous. I learned about overtraining when I was getting my Masters in Exercise Science. The American College of Sports Medicine has published a comment on overtraining, citing that excessive exercise can cause a variety of symptoms, including fatigue, depression, sensitivity to stress and impaired immune system function (Reference 1). 

The prevailing wisdom was that overtraining was not such a big deal and these symptoms were generally self-limiting and benign. Recently however, a new area of research suggests that this may not be the case. I read a newly published article in the Journal of the American College of Cardiology that was eye opening and prompted me to dig deeper into this question.

The Study
In this investigation of the Copenhagen City Heart Study cohort, 1,098 healthy joggers and 3,950 healthy non-joggers were followed for 10 years (Reference 2). The exercise habits of the runners were measured and the impact of these habits on long term risk of death were examined. The results were shocking.

Based on the reported intensity, frequency, and duration of training, runners were broken up into 3 categories; light joggers, moderate joggers, and strenuous joggers. The light joggers had a statistically significant 78% lower risk of dying when compared to sedentary subjects. The moderate joggers had a nonsignificant 34% lower risk of dying, while the strenuous joggers had a nonsignificant 197% increased risk of dying.

Subjects that ran the hardest and longest had no benefit to longevity when compared to those that didn’t exercise at all! 

Why Didn’t The Strenuous Exercisers Live Longer?
This is the million dollar question. The authors of the study offered several possibilities with plenty of references. Most of the proposed mechanisms dealt with damage to the heart. I picked up the relevant articles and looked at them in detail. Here is what I found as far as potential problems with very intense exercise:

1) Pathological restructuring of the heart and large arteries (Reference 3).

2) Elevations in troponin after intense exercise, which is a highly specific marker of myocardial cell damage (Reference 4).

3) Premature aging of the heart (Reference 5).

4) Increased risk of myocardial fibrosis, which increases risk of arrhythmia (Reference 3).

5) Increased coronary artery calcification (Reference 3).

6) Large artery wall stiffening (Reference 3).

7) Increased oxidative stress (Reference 3).

8) Renal dysfunction (Reference 3).

9) Increased risk of atrial fibrillation (Reference 3).

10) Immune system dysfunction (Reference 3).

The research here is in a relatively early stage and there is clearly more work to be done. However, after going through these studies in detail, I think there is something to the idea that very long and/or very intense exercise may be more harmful than beneficial to health and longevity.

This in no way lessens the astronomically positive impact of physical activity on health. Even in this study, those considered “light joggers” had a stunning 78% lower risk of dying during the follow up period. It’s just that as intensity goes up, health benefits may go down. 

As far as recommendations, here is what I tell my clients:
1) Limit total exercise to 45-60 minutes per day max and don’t go crazy with the intensity. Think of a time when you were late to an appointment and you were walking as fast as possible to get there without running. That is the level of cardio intensity I have my clients shoot for. If you are young, healthy and in good shape, a few intervals of increased speed for 30 seconds thrown in are probably OK.

2) Avoid marathons, long bike races, and “survival” races. They are not necessary for weight loss/health promotion and may be damaging to your health.

3) As far as weight training, keep the intensity moderate. Most of the studies I looked at were about cardiovascular exercise, but there is some evidence that any really intense exercise, even if it is of short duration, may cause issues. I always tell my clients that when they finish their cardio or weight training, they should feel like they could do a bit more.

It may just be that when it comes to exercise, the goals of health promotion and longevity may differ radically from the goals of maximizing strength, speed, and physical performance. It also may be that a program designed to reach one of those goals excludes you from reaching the other.

1) https://www.acsm.org/search-results?q=overtraining

2) Schnor P, et al. Dose of jogging and long term mortality. Journal of the American College of Cardiology 2015; 65:411-19.

3) O’Keefe JH, et al. Potential adverse cardiovascular effects from excessive endurance exercise. Mayo Clinic Proceedings 2012; 87:587-95.

4) Shave R, et al. Exercise-induced cardiac troponin elevation. Journal of the American College of Cardiology 2010; 56:169-76.

5) O’Keefe JH, et al. Exercise for health and longevity vs peak performance: Different regimens for different goals. Mayo Clinic Proceedings 2014; 89:1171-75.