“Diet is king, up to the standard energy compensation rate.”

In today’s episode, we review a recent study published from the College of Sports Medicine in Sports and Exercise, in an effort to understand the connection between exercise minutes and weight loss. In other words, how much exercise is required to lose significant weight for those starting their first exercise program?

The article, “Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise,” by Flack et al., addresses the minutes of exercise needed to see significant weight loss as measured in fat loss. Two groups and a control were compared to measure the number of days individuals work out, taking into account energy compensation (added calories during the week).

It is suggested that approximately 320 minutes of exercise spread out over six sessions, or 3000 calories of expenditure per week, is required to compensate for additional calories consumed common for those entering an exercise program. Furthermore, those who engage in physical activity two days a week vs. six days a week, compensated with the same amount (approximately 1000 calories). However, only those working out more days a week showed significant weight loss as measured in fat.

Increased rates of leptin is associated with increased satiety. In other words, if you have higher levels of the hormone, you get full faster. Companies promoting weight loss culture often attempt to exploit this connection by selling products that increase leptin.

In the reviewed study, those who work out more minutes per week saw a measurable decrease in leptin. This was found to be consistent with rodent studies indicating that decreased leptin increased hypothalamic sensitivity to leptin. Thus, with increased sensitivity, it requires less leptin for the same effect. This finding is likely to spark future research about how we prescribe exercise to individuals.

Welcome to 038 – Exercise Minutes Required For Weight Loss

1. What We Do:
   
   • Behavioral Medicine and Health Psychology
     
   
   
2. Today:
   
   • Reviewing a study reported in the New York Times on the amount of exercise needed for weight loss (as measured in fat), a study that reveals a surprising connection with leptin hypothalamic sensitivity.
     
   
   
3. Personal Challenge
   
   • No Alcohol for 90 days Update
     
   
   

Question Of The Day

1. How many minutes are needed for weight loss?
   
2. Does the calories I consume damage my efforts?
   
3. What role does leptin play in weight loss?
   

Caution Moving Forward

1. Today is about weight loss as measured in fat loss, and the amount of activity needed for measurable improvements.
   
2. Benefits
   
   • Improvements in Mood
     
   • Cardiac Efficiency
     
   • Improved Stress Respons
     
   
   
3. Weight loss should not be the only metric you use to measure success. If it is, you are likely not to stick with it, thus losing all benefits.
   

Study Overview (Purpose, Sample, and Measures)

1. From the American College of Sports Medicine, in Sports & Exercise
   
2. “Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise,” by Flack et.al.
   
3. Purpose: To evaluate energy expenditure compensation for those in a twelve-week aerobic exercise program.
   
   • We all increase our caloric intake when we enter an exercise program. How much exercise is needed to overcome this?
     
   
   
4. Participants were sedentary adults between the age of 18 and 40 years of age with a max BMI of 35.
   
5. Comparison Groups: Six exercise sessions per week, vs., two exercise session per week, vs., sedentary control group.
   
6. Diet was not controlled for.
   
7. Exercise groups used heart rate zone method to measure intensity.
   
8. Various hormones were also measured (insulin, leptin, etc.).
   

Results

1. Caloric Expendature:
   
   • Six Sessions Per Week Group: Burned an average of 2753.5 Calories Per Week, Exercising 320.5 Mins.
     
   • Two Sessions Per Week Group: Burned an average of 1490.7 Calories Per Week, Exercising 188.8 Mins.
     
   
   
2. Energy Compensation
   
   • ~1000 Calories Per Week for both Six Week and Two Week Groups.
     
   
   
3. Hormone Surprise
   
   • Leptin level decreased with increased exercise minutes.
     
   • This is contrary to the fact that increased leptin increases satiety.
     
   • Decreased Leptin in rodent studies has found increased hypothalamic sensitivity, thus, you need less leptin for the satiety effect.
     
   
   

Conclusions

1. If you are seeking weight loss, you need to exercise about 300 minutes per week in an aerobic zone. This equals about 3000 calories assuming 10 calories for every minute of exercise.
   
2. Everyone compensates with calories. However, this appears to plateau at around 1000 calories. Thus, if you are only working out two days a week, you are unlikely to surpass this natural compensatory behaviour.
   
3. Leptin hypothalamic sensitivity is a new area of research that might strongly impact what we prescribe to those interested in weight loss.
   

My Own Observations

1. I lose the most weight when marathon training.
   
   • Running ~ 4hrs qweek.
     
   • Burning ~4000 calories qweek.
     
   
   
2. Remember:
   
   • Weight loss requires something monumental: You must be consistent over the long haul.
     
   • There are no short cuts to weight loss.
     
   • Diet Remains King – When you are only working out a couple times per week.
     
     • But a bad diet has many other negative effects other than stubborn weight loss.