Genetics helps explain why some clients do not respond to exercise. Fortunately, science has uncovered how to turn your nonresponders into responders.
Trainers love responders. These clients succeed immediately and continue month after month, losing weight, gaining strength, slicing off inches, normalizing hypertension, improving cholesterol levels, sleeping better and feeling better overall.
Then there are nonresponders. They hire trainers, have good intentions, train regularly and try as hard as they can to improve their health habits. But they do not lose much weight or fat, nor do they improve their muscle strength. They may feel better or sleep better, but they never seem to get the results they are looking for.
Frustrated nonresponders and their trainers need to understand that there may be a good reason for this lack of progress. It’s possible these clients have a genetic makeup that resists traditional exercise programs. Then the question is, if some people are natural-born nonresponders, is it even possible to turn them into responders? Multiple research studies suggest the answer is yes—especially if you add intensity, duration and resistance to their workouts.
Add Some Intensity to the Cardio
One way to help nonresponders is to increase the duration and/or intensity of the cardio training, according to one recent study.
Ross, de Lannoy & Stotz (2015) investigated whether exercise of different intensities and durations improved cardiovascular fitness (cardiorespiratory fitness was measured using a graded exercise test in which subjects walked on a treadmill). The study had 121 middle-aged (53.2 years) subjects (75 women, 46 men), all of whom were abdominally obese. Everybody completed at least 90% of the five weekly workouts over 24 weeks. Subjects were randomly assigned to one of three training protocols:
- low-amount, low-intensity training—30 minutes at 50% of peak VO2, designed to burn 180–300 calories per session
- high-amount, low-intensity training—60 minutes at 50% of peak VO2, designed to burn 360–600 calories per session
- high-amount, high-intensity—40 minutes at 75% of peak VO2 designed to burn 360–600 calories per session
After 24 weeks, the researchers tallied the nonresponders in each group. In the low-amount, low-intensity group, more than one-third (15 of 39) were nonresponders. In the high-amount, low-intensity group, the nonresponse rate declined to about one-sixth (9 of 51). Notably, the high-amount, high-intensity group had zero nonresponders.
The authors suggested that this study provides prescription options for trainers who work with beginning adult exercisers because it illustrates the results of adding quantity and intensity to workouts (see Tables 1 and 2 for more on programming for nonresponders).
Interval Training Also Works
Bacon et al. (2013) combined data from several studies to investigate the effectiveness of adding intervals to continuous exercise. The main finding was that interval training improves VO2max beyond the gains reported with continuous cardio training.
The meta-analysis, which evaluated studies that used interval training either alone or combined with continuous training, found a mean increase in VO2max of 500 milliliters per minute, compared with 400 mL per minute in the HERITAGE study described in the sidebar. The analysis also suggested that longer intervals combined with high-intensity continuous training can produce increases in VO2max in almost all relatively young adults.
It appears that intervals of 3–5 minutes are especially effective for improving VO2max. The nine studies that saw the largest increases in VO2max (~850 mL per minute) generally used intervals of 3–5 minutes with 2-minute rest periods and high-intensity continuous training.
Do We Really Need Cardio?
Given that many nonresponders identified in research studies were doing long-duration, low-intensity, continuous exercise—that is, cardio—while interval training and higher-intensity continuous exercise eliminated nonresponders in some cases, it’s worth asking: Do our clients really need cardio?
Many clients love cardio because it gives them the best results. These people thrive on taking long walks, running along the beach or in the mountains, riding an exercise bike listening to their playlist, running on a treadmill and getting lost in their thoughts, and/or swimming lap after lap. However, some clients either don’t respond to cardio or do not enjoy it (or both).
Nevertheless, many trainers prescribe cardio whether clients like it or not. Or, perhaps, the clients keep doing it because they think cardio is the way to maximize results.
Interestingly, when asked if cardio is essential to an exercise program, many trainers say their clients need it in their program. Yet based on results from the HERITAGE study, it may be safe to rethink the use of cardio for so many clients. After all, there is plenty of research and anecdotal evidence that so-called nontraditional forms of training, or “metabolic training,” can give clients better results than cardio.
Next up, we’ll review research pointing to viable alternatives to cardio.
Korean Tae Kwon Do for the Elderly
Brudnak, Dundero & Van Hecke (2002) wanted to find out if the “hard” martial art of Korean tae kwon do could help senior citizens improve muscle strength, flexibility and balance and thereby reduce falls—a leading cause of death in this age group.
The researchers found that subjects who attended more than 85% of classes averaged more push-ups, increased their trunk flexion and improved their balance time on each foot. Equally important, the dropout rate was low, suggesting that elderly exercisers are capable of performing Korean tae kwon do and that it can hold their interest.
Yoga for Obese Teen Boys
Seo et al. (2012) investigated the use of yoga training to improve the metabolic profiles of obese boys. Twenty obese adolescent boys, all about 14 years old, performed yoga asana three times per week for 8 weeks at 40%–60% of heart rate reserve (HRR). The boys were tested on the following metabolic measures: body weight, body mass index, fat mass, body fat percent, fat-free mass and basal metabolic rate.
After 8 weeks, body weight, body mass index, fat mass and body fat percent were significantly lower, while fat-free mass and basal metabolic rate were significantly higher. The authors suggested that yoga can be an uncomplicated therapy for obese adolescent boys.
Tremblay, Simoneau & Bouchard (1994) compared the effect of continuous exercise versus medium-intensity interval training on VO2max, estimated calories burned, sum of six skinfolds, and muscle enzymes that promote fat use during exercise. Subjects were aged 18–32. There were two groups:
• Continuous exercise. Eight men and nine women performed a 20-week endurance training program by cycling four, then five, times per week for 30 minutes, with sessions increasing to 45 minutes toward the end of program. Intensity was 60% of HRR at the start of training and had risen to 85% by the end.
• Medium-intensity interval training (MIIT). This technique produced notably different results from those gained through continuous exercise, so we will explore MIIT in much greater depth, as it points to possibilities for nonresponding clients.
In the MIIT protocol, five men and five women started with 25 half-hour sessions of continuous cycling at 70% of HRR, with half of the training sessions completed by week 5. After that, they performed 19 short-interval trainings and 16 long-interval trainings over 15 weeks. The short-interval trainings had 10 bouts of 15-second intervals, later increasing to 15 bouts of 30-second intervals. The long-interval trainings had four to five 60-second bouts, increasing to 90-second bouts.
The rest interval was determined by noting when heart rate returned to 120–130 beats per minute. Short-interval intensity was 60% of maximal work output in 10 seconds, while long-interval intensity was 70% of maximal work output in 90 seconds.
Study results found that VO2max increased with both training programs, rising 36.6–48.2 mL/kilogram/min for continuous training vs. 38.7–48.6 mL/kg/min for MIIT. Calories burned during the entire study showed that the continuous exercise group used 28,757.04 kcal, whereas the MIIT group used 13,829.17 kcal.
The data on skinfold reduction was most intriguing. It showed that even though the continuous training group burned twice as many calories, the MIIT group had a much larger reduction in the sum of six skinfolds. The continuous group reduced its six-skinfold sum from 79.2 millimeters to 74.7 mm, while the MIIT group reduced the same measures from 94.2 mm to 80.3 mm. When the decrease in the skinfolds sum was divided by calories burned, subcutaneous fat reduction was nine times greater in the MIIT program.
Muscle enzymes data was also revealing: The MIIT program increased three of the four enzymes measured, while the continuous program produced no gains. This showed that the MIIT program boosted the enzymes promoting fat use to produce energy for muscle contraction, and increased fat use postexercise.
Weight Training Is the New Cardio
Resistance training is another avenue for turning nonresponders into responders. In addition to burning calories, resistance helps clients improve fitness, reduce weight and body fat, increase bone mineral density and improve self-confidence. Artero et al. (2012) did a review of literature on the effects of increased muscle strength and found that it has a protective effect on all-cause and cancer mortality in healthy middle-aged men, men with hypertension and patients with heart disease.
Increased muscle strength is associated with reductions in weight and fat, a lower risk of hypertension and decreased prevalence of metabolic syndrome. After reviewing literature on the benefits of resistance training, Westcott (2012) reported that they include improvements in sports and fitness performance, movement control, walking speed (in the elderly), functional independence (for elderly clients), cognitive abilities and self-esteem. Moreover, resistance training can promote bone development, with studies showing a 1%–3% increase in BMD (Westcott 2012). This type of exercise has also been shown to reduce low-back pain and decrease the discomfort of arthritis and fibromyalgia (Westcott 2012).
McGuigan et al. (2009) investigated the effect of resistance training on overweight or obese children. There were 26 girls and 22 boys (mean age 9.7 years) who weight-trained 3 days per week for 8 weeks. The study found a 2.6% decrease in body fat, and a significant increase (5.3%) in lean body mass. Strength improvements included one-repetition maximum squat (74%), number of push-ups in 1 minute (85%), countermovement jump height (8%), static jump height (4%) and power output (16%).