By Mike Bracko

The media and some research scientists seem to take perverse pride in talking about the so-called “obesity epidemic” and the percentage of the population who are over-weight, obese, and physically inactive.  However, there are researchers who indicate the risk for disease from being overweight or obese is exaggerated when other factors are not taken into consideration.  Many trainers work with clients who have a high level of fitness, but cannot lose weight, or fat, and are otherwise healthy.  This may be because the client is a “non-responder.  These are people who do not respond, or respond very little, to medium intensity continuous training (MICT).  This article will explore the ways to help a non-responder become a responder.

Learning Objectives

  1. Describe deviance amplification as it relates to the media talking about obesity and physical inactivity.
  2. Outline the thoughts and ideas of many researchers who are calling into question the so-called obesity epidemic.
  3. Explain how a client, who’s fit and fat, might be a “non-responder” and how we can alter his/her training to improve the response from exercise.

Deviance Amplification

The media and some researchers seem to take pride in talking about people who are overweight, obese, and/or inactive.  The media exaggerates a problem to profile the negative.  This is called deviance amplification, a media phenomenon defined as a cycle of increasing numbers of reports on a category of antisocial behaviour or some other undesirable event, leading to a moral panic.  Blair and LaMonte (2006) counter the media hype by indicating the health hazards of obesity have been overstated, and there is a mismatch between evidence for obesity as a health risk and the intensity and amount of attention the issue receives in the scientific and lay press.  Moreover, Blair and LaMonte (2006) indicate most of the large prospective studies on obesity and health outcomes do not account for a major confounder of this association, that being physical activity.  They suggest the focus should not be on obesity per se, but rather on poor diet and physical inactivity.

The Obesity Myth

Campos (2004) describes the “politics of obesity”, indicating there is a cultural bias of those who are over-weight and obese.  Campos (2004) indicates there is no question obesity increases risk for heart disease, diabetes, and other diseases.  But the risk for disease from being overweight or obese is exaggerated when other factors are not taken into consideration, such as socioeconomic status, fitness level, and decent health care.  Lee and Cubbin (2009) suggest people of color, low socioeconomic status, and women have less access to safe and affordable places to exercise, less leisure time and energy, and less exposure to networks supporting exercise, and that these factors are significant barriers to exercise.

Campos, et al., (2006) indicate a growing number of researchers from various academic disciplines, are calling the claims of an obesity epidemic into question.  Kim and Popkin (2006) indicate that the definition of optimal body mass index needs to be challenged based on the scientific evidence.  Body mass index is one of the most commonly used variables to categorize people into over-weight and obese categories.

Gard and Wright (2005) suggest that the long-term consequences of obesity are unknown.   Flegal, et al., (2005) found that being overweight was not associated with excess mortality.  Moreover, risks of mortality associated with obesity were lower in 1988-1994 (with a follow- up 2000) & 1976-1980 (with a follow-up 1992) than in 1971-1975.  Being underweight and obese were associated with increased mortality relative to normal weight.  However, the researchers state the impact of obesity on mortality may have decreased over time, perhaps because of improvements in public health and medical care.

Lee, Blair and Jackson (1999) investigated the health benefits of leanness and the hazards of obesity, while at the same time measuring cardiorespiratory fitness.  The researchers found that after adjustment for age, examination year, cigarette smoking, alcohol consumption, and family history of heart disease, unfit (low V02max), lean men had double the risk of all-cause mortality than fit, lean men. Unfit, lean men also had a higher risk of all-cause and cardiovascular disease (CVD) mortality than did men who were fit and obese (“fit and fat”).  Unfit men had a higher risk of all-cause and CVD mortality than did fit men in all fat and fat-free mass categories. Unfit men with low waist girths had greater risk of all-cause mortality than did fit men with high waist girths.

Turn a Non-Responder into a Responder

Bouchard, et al., (1999) were the first researchers to find that some people do not respond to MICT.   They investigated the differences in improvement of V02max from an identical training program in 481 sedentary adult Caucasians from 98 two-generation families.  They were tested for V02max on cycle ergometer twice before, and twice after training.  The subjects rode cycle ergometers at a heart rate of 55% of V02max for 30 minutes/day for 14 weeks, then increased training to a heart rate of 75% of V02max for 50 minutes/day for 6 weeks.  They trained three days/week.

The results show an average change in V02max of 400 ml/minute.  Some subjects increased their V02max more than 1000 ml/minute.  Many subjects did not improve V02max or had little improvement.  Roth (2007) suggests there is no normal response to exercise.  We can expect clients who don’t respond to “cardio” or respond very little.  Other clients will have dramatic improvement.

Ross, de Lannoy, and Stotz (2015) studied the effect of training at different intensities and durations on improvements in fitness (V02max).   The purpose of their study was to find out if it is possible to eliminate non-responders.  They had 121 middle-aged (53.2 years) subjects, 75 females and 46 males, all of whom were abdominally obese.  They had their V02max tested at 4, 8, 16, and 24 weeks.  All subjects completed 90% of the 5-weekly work-outs over 24 weeks.

Subjects performed one of three training protocols: 1) low-amount, low-intensity for 30 minutes at 50% of peak V02 which was designed to burn 180 – 300 kcals/session, 2) high-amount , low-intensity for 60 minutes at 50% of peak V02 which was designed to burn 360 – 600 kcals/session and 3) high-amount, high-intensity for 40 minutes at 75% of peak V02 which was designed to burn 360 – 600 kcals/session.  The results show the number of non-responders at end of study: 38.5% (15 of 39) in the low-amount low-intensity group, 17.6% (9 of 51) in the high-amount low-intensity group, and 0% in high-amount high-intensity group.

Bacon, et al., (2013) conducted a meta-analysis to investigate effectiveness of interval training, or adding intervals to continuous exercise, on improvements in V02max.  Their main finding was that interval training produces improvements in V02max greater than those reported with MICT.  They reported that the nine studies that had the largest increases in V02max used intervals of 3–5 minutes with 2 minutes rest, or used high intensity continuous training.

Ross, de Lannoy, and Stotz (2015) suggest the guidelines on physical activity published by many associations indicating Americans should do 150 minutes/week of MICT (or 75 minutes/week of higher intensity exercise or a combination of the two) are insufficient to improve cardiovascular fitness for 38.5% of subjects.  Moreover, these guidelines are so broad and general they apply to a small percentage of people in North America.

Through the research presented in this article, higher intensity cardiorespiratory training appears to be a key factor to making a “non-responder” to exercise more of a “responder”. It’s important to note, however, that one must progress to higher intensity exercise versus starting them off at higher intensities.