Weight loss

I think I have everyone’s attention now. Although many came to triathlon at its beginning because it just sounded crazy, and let’s admit it, pretty stupid, the demographics have changed quite dramatically over the past few years. Many come into the sport now to lose weight. Yet, the ‘how do I lose weight’ question pops up regularly at Tri club meetings, group rides, and on internet forums (fora for those of you born in ancient Rome).

It’s pretty easy to do a long article on the topic so I’m going to stick to the fundamentals, and give some tips on how to lose weight in a healthy manner.

1. Thermodynamics 101: there are heated debates about whether the first law of thermodynamics should also apply to us. Yes, there are some metabolic issues, there are some efficiency issues, and water soluble and insoluble fibers, etc., but the bottom line is that the vast majority of studies show that if you want to lose weight, you must get less calorie in, than you get out. In other words, if you get in 3000kcal and burn 2500kcal (including basal metabolism), you will likely go on packing on weight.
Rule 1: get less calories in than you get out.

2. Overestimate / Underestimate: most people tend to underestimate how much they eat, and overestimate how much they burn. There are numerous apps that exist if you want to count calories, so these are a good start. Now, to estimate how much you burn, that gets trickier. Generally, running amounts to your weight in kg time your distance in km, on a flat course. So, if you run 10km and weight 70kg, that’s 700kcal. On the bike, it’s a bit more difficult, because it depends on air resistance, and a bunch of other factors that are difficult to measure. But a rough estimate is that an hour at an easy pace for someone around 140-150lbs shouldn’t be more than 350-400kcal, and 600kcal for someone bigger. When pushing the pace, you can assume a lighter person will be around 600kcal to 700kcal and 800 to 900kcal for someone bigger. These are crude lower bounds, which is good since the goal is to get more out than in. In the water, the estimates also range between 400kcal and 900kcal, depending on how fast you swim. A rule of thumb is to count 700 for 3000yds.This probably underestimates a bit, but once again, the goal is to lose weight.
Rule 2: running for 20min on the treadmill, burns less energy than a venti vanilla latte at starbucks.

Food items: that’s where things get really tricky, because you want to lose weight, but also stay healthy. So rather than writing a nutrition book, something I’m not qualified to do anyway, there are a few rules that you can use:
-Focus on fresh fruits, fresh vegetables, lean meats, seafood, various nuts, and fibers.
-Carbs are NOT bad. You are most likely exercising, and you need to replenish your glycogen stores. Make sure that you eat soon after working out, and eat carbs at that moment. Note: the calorie balance still applies at that moment. It applies ALL the time.
-Stay hydrated, and favor water. It’ll keep your stomach relatively full, and will limit the amount of food you can get in.

Other general rules:
-Try to avoid snacking too late. Avoid eating dinner past 7pm whenever possible. Or at least, avoid dinner too close to bed time.
-Don’t skip meals. In particular breakfast. A couple of studies show that missing out breakfast leads to consuming more calories during the rest of your day.
-Don’t lose more than 2-3lbs per week.
-Stay clear of the various unhealthy weight-loss strategies, that promise quick weight loss, that rely on ridiculous assumptions with no underlying scientific evidence.

That will probably not answer all your questions, but that’s a good start for those who are trying to lose weight, stay healthy, stay active, and race.


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