I have talked many times about how running has fueled my weight loss and maintenance through the years. Many people take up running but don’t lose weight – and this week I have had the same old report brought up twice about weight loss and exercise. Bottom line – losing weight is hard work requiring changes in eating and exercise.
One of my favorite Bloom County comics involves Opus looking at an index of diet books and deciding how to reshape himself, with Milo offering the basic advice ‘how about eat less, and exercise?’. Here it is:
Perhaps you have never heard the ‘everyone knows’ adage about weight loss. It is typically delivered as part of a trifecta on ‘why you shouldn’t run’ – weight gain (or non-loss) is first, then ‘bad for your knees’ and finally ‘bad for your heart’.
‘Bad for your Heart’: The myth around the heart is related to a very specific look at the long-term impact of ultra-distance runners over many years. These are people running fast paces for 100+ miles per week year round and competing at an elite level. And in a small of cases they found that the hearts of those studied showed degradation over time. But at the same time the study showed that for low-to-moderate volume runners (<60 miles per week) there is considerable benefit. So the message is that if you are an elite runner, take care of your cardiac health, and for all others … also take care, but expect some benefit.
‘Bad for your Knees’: Once again, studies have shown that for high-volume elite runners there is an increased risk of injury. But guess what poses a greater risk? Obesity! Study after study has shown that running helps stimulate the cells that create more cells – whereas a sedentary life sends the opposite signal. Also, studies show running can be beneficial for joints as it strengthens the surrounding musculature and increases bone density.
‘You Won’t Lose Weight’: This one goes back to a flawed New York Times article several years ago, which basically said that the ‘exercise = weight loss’ thinking is flawed. The article isn’t that simple, but does talk about weight loss while exercising ‘with all things being equal’ should happen … but all things are not equal.
In other words, they allowed the study group to eat more if they were hungrier and used that to prove why running doesn’t help with weight loss. Which is fairly nonsensical and potentially bad science depending on how the study was designed. It seems that part of the study had a goal – to see if the introduction of running into an otherwise unhealthy lifestyle can cause weight loss.
But what seems to have been lost – similar to the studies on joints and heart – is that there is much more to the study. The most important stuff was lost in the hype of ‘running doesn’t help you lose weight’. Here are few other things:
- One big issue is overestimating caloric impact of exercise – in other words, if you are burning 500 calories in an hour, but not accounting for your ‘base burn rate’ (how many calories you’d burn while just being awake) you will overestimate the impact.
- Another culprit – not controlling intake! Maybe you’ve heard you need to ‘carbo load’, or that ‘if you run you can eat anything’. Guess what? Neither is really true. Certainly if you are running long distances and amassing high mileage totals you need to fuel up, but if weight loss is a goal you need to monitor your caloric balance.
- All calories are NOT equal! If you are burning calories running (or biking) hills compared to flat roads you will have a different burn rate, also if you are lifting weights your balance of fat-to-muscle burning and building will be different.
- Not all ‘Loss’ is equal: there is more than a little truth to the saying ‘the scale lies’ – through exercise you will be reshaping your body, and might find yourself more tone and with smaller clothes sizes without a major move on the scale.
- The closer your target, the harder to hit: this is true about eating as well as exercise – if you are 100 pounds overweight, your caloric changes in eating and exercise will have proportionately more impact than if you are 10 pounds overweight.
- Everyone is different: there are genetic and metabolic factors that are unique to each person, and the way each of our bodies reacts to exercise is also different.
One thing that has come up again recently is that running has a disproportionate caloric burn compared to walking, and studies are showing that walkers are hungrier after exercise than runners. The impact of that is double – there is a lower calorie burn per hour, and a greater likelihood to overcompensate through eating.
But it all comes back to a very simple equation: Weight Loss = f (Calories Burned – Calories Consumed). You burn calories 24 hours a day, but can accelerate that process through exercise, and as you exercise your body becomes more efficient burning calories all day long. But if you don’t pair up with a serious look at how and what you are eating, it is possible that all of your hard work will fail to produce the desired effect of weight loss.