I have a friend, a retired pro racer, who says weight management is easy, “Just ride more and eat less.” But it’s not this simple.
Why It Matters
Being even slightly overweight can increase your risk of dying prematurely by six percent and increases the risk by 73% for an obese person. Researchers concluded this after reviewing the mortality data in three studies that followed more than 225,000 adults over age 50, for eight to 20 years. (Annals of Internal Medicine, April 3, 2017).
According to the Centers for Disease Control and Prevention (CDC) about one-third of U.S. adults are overweight and another one third are obese. The CDC uses the body mass index (BMI) to indirectly assess body fat and thus whether an individual is overweight or obese. You can calculate your BMI here.
An earlier macro study appeared to show being slightly overweight was healthful. This column No Amount of Overweight is Healthful) by Dr. Gabe Mirkin explains why this flawed.
The problems with BMI
BMI is a person’s weight in kilograms divided by the square of the height in meters. A 5’10” (1.78 m) male is usually considered to be overweight at 175 pounds (75 kg) and obese at 210 pounds (90.7 kg).
BMI stats are useful in large epidemiological studies. However, because a person’s weight is a function of both body fat and muscle, a high BMI may or may not diagnose the body fat or health of an individual. BMI also doesn’t assess an individual’s metabolic health “like their insulin resistance, markers of inflammation and blood pressure, triglyceride, cholesterol and glucose levels. Nearly half of those classified as overweight and about a quarter of those classified as obese were metabolically healthy by these measures. On the other hand, 31 percent of those with a ‘normal’ body mass index were metabolically unhealthy.” (New York Times)
As a cyclist you have more muscle and less fat than the average person. If you are five or ten pounds over what the BMI defines as normal you probably aren’t actually overweight because of your higher proportion of muscles. Whether your BMI says your overweight or normal may be misleading — ask your health care professional to do the appropriate metabolic tests.
Weight and Aging
Scientists thought each decade after age 30 your metabolism slowed by about 2% per decade of life. If you weigh 175 lbs at age 40 and continue the same dietary and exercise habits then you’d weigh 178.5 lbs (2% more) at age 50 and 182 lbs at age 60.
In a new macro study researchers pooled data from 40 years of studies of more than 6,400 participants, ranging in age from eight days to 95 years. Researchers found the changes in the metabolic rate across the life span were different than expected. “According to the new study, metabolism can be viewed as four distinct life stages: Energy expenditure accelerates rapidly to 50 percent above adult values at one year of age; declines slowly to adult levels by age 20; remains stable between ages 20 and 60; and declines steadily after age 60.” (Washington Post)
If your age is between 20 and 60 and you’re gaining weight it’s not your body’s fault!
Exercise and Calories Burned
For most of us it’s easier to increase the amount of riding and other exercise, which are fun, than to eat less, which isn’t fun.
The weight loss calculation that people – including exercise scientists – use is simple: If the total daily calories burned are more than the total calories consumed, then the individual will lose weight. Daily calories burned are the sum of calories burned at rest (basal metabolism or BMI), burned through activities of daily living (ADL) and through exercise. This is the calculation I’ve used personally and with clients. Most people trying to lose weight monitor the total number of calories they burn each day and number of calories they eat each day. There are apps you can use for this.
According to the weight loss calculation if you burn 500 calories on a two-hour bike ride it has the same effect as foregoing about a pint of ice cream.
However, in study after study people trying to lose weight didn’t lose as much weight as the weight loss calculation predicted.
Scientists wondered why and reviewed an interesting and influential 2012 study of hunter-gathers who regularly walked or jogged for hours. The study examined their caloric burn rate. Surprisingly the hunter-gathers burned about the same number of total daily calories as relatively sedentary Westerners. The active hunter-gatherers daily eating pattern was few calories while hunting all day and then eating at night and in the morning before hunting. While hunting without their bodies anticipated starvation as they stalked their food and the bodies dialed back the caloric burn rate.
The same phenomenon occurs in people with more normal eating patterns who are eating less. A 2021 macro study of 1,754 adults just reported in Science Direct found our bodies tend to automatically compensate for at least a quarter of the calories we expend during exercise. In other words for every 100 calories you think you’re burning while exercising, you’re actually burning only about 72 calories. The scientists called this energy compensation.
Taking into account energy compensation you’d actually have to ride 2:45 hours to burn off calories equivalent to not enjoying the pint of ice cream.
The energy compensation varied considerably with body composition. In general the more overweight a person is the fewer calories actually burned per hour of exercise. This may be due to differences in how much different individuals compensate and some people may be more may be more likely to accumulate body fat. Or the process might be more general. As people get fatter, their bodies might tend to compensate more for the calories burned during activity, making losing fat progressively more difficult. (New York Times)
The bottom line is that to lose weight you need to exercise more than you thought or also eat less.
Weight Training May Help
Here’s some good news. A new study found people who regularly do any kind of strength training exercise are significantly less likely to gain weight, whether they do aerobic activity or not.
Researchers looked at 12,000 mostly middle-aged people. At the start of the study none of them were obese measured by BMI. Knowing the problems with BMI the researchers also measured waist circumferences and body-fat percentages.
“Men and women who reported strengthening their muscles a few times a week, for a weekly total of one to two hours, were about 20 percent less likely to become obese over the years, based on B.M.I., and about 30 percent less likely, based on waist circumference or body-fat percentage.” These results are independent of diet, genetics and other factors. The study found a correlation between resistance training and gaining weight, but didn’t demonstrate any causality.
The American College of Sports Medicine recommends doing 8 to 10 resistance exercises two or three times a week. This would take at least half an hour per session. I wrote this column on Anti-Aging – American College of Sports Medicine Recommendations.
Most of us love riding our bikes and if we have another half hour in a day we’ll go for a longer ride so meeting the ACSM recommendations may be challenging. I’ve created a simple minimum 15-minute program: Anti-Aging: 4 Essential Year-Round Home Resistance Exercises. You can do these exercises at home with no special equipment. I’ve also written these two related columns:
I’ve also written several columns on nutrition:
- Anti-Aging: 7 Nutrition Myths
- What’s the Best Food for Cycling
- Best Recovery Food and Drink
- Nutrition for Performance
I’m researching a new eBook on Cycling in Your 70s, 80s and Beyond. I’m in my 70th decade and very interested in this. Some of the above material is from my research; however, what’s in this column applies to all cyclists.
My eBook Healthy Nutrition Past 50 covers
- The key role of carbohydrates in providing the energy you need and many of the vitamins and minerals.
- The role of protein and nourishing protein choices.
- The important role of fat in your diet, and healthy choices to get that needed fat.
- The principal vitamins and minerals you need.
The 28-page Healthy Nutrition Past 50is $4.99.
Anti-Aging – 12 ways you can slow the aging process has a chapter devoted to resistance training. I explain how to do resistance training correctly and give you choices of 14 lower body exercises, 9 upper body exercises, and 7 core exercises. Coach Dan Kehlenbach demonstrates how to do each exercise without special equipment. I provide an annual plan to integrate resistance training with endurance riding and intensity workouts. The 106-page Anti-Aging – 12 ways you can slow the aging process is $14.99.
Coach John Hughes earned coaching certifications from USA Cycling and the National Strength and Conditioning Association. John’s cycling career includes course records in the Boston-Montreal-Boston 1200-km randonnée and the Furnace Creek 508, a Race Across AMerica (RAAM) qualifier. He has ridden solo RAAM twice and is a 5-time finisher of the 1200-km Paris-Brest-Paris. He has written nearly 30 eBooks and eArticles on cycling training and nutrition, available in RBR’s eBookstore at Coach John Hughes. Click to read John’s full bio.