How Much Fat Can You Lose In A Week?

How much fat can you lose in a week? For most people losing 1lb of fat in a week is tough because it requires an extra 5 miles of running per day!

Philipp Halfmann

For tennis players, it can be difficult to lose body fat especially if their season is rather long.

You need enough energy to compete and train yet you need to decrease fat mass to become more athletic and hence move better on the court.

Unfortunately, many athletes and coaches have unrealistic goals when it comes to weight loss because they rely on inadequate information.

How much body fat one deposits or withdraws from fat cells depends on the energy balance each day – the amount of energy (kcal) consumed vs. energy expended.

How Many Calories Is 1lb of Body Fat?

1lb of body fat represents ~3,500 kcal because adipose tissue (fat cells) are composed of:

The fat content of 1lb body fat is ~87% and 1lb equals 454g. Therefore, 395g out of 454g is pure fat (454g x 0.87 = 395g) and hence yields 3,555 kcal (395g x 9kcal/g = 3,555 kcal).

The American College of Sports Medicine (ACSM) guideline states that loosing 1-2 lbs of body fat per week is attainable. Really? Maybe if you are on a cocaine diet!

Why Most People Cannot Lose 1lb Of Fat In A Week

For most people losing 1-2 lbs of fat in a week is a ridiculous goal because it is unrealistic since losing 1-2 lbs of fat translates to losing 3,500 – 7,000 kcal per week.

The average person burns ~100 kcal for every 1 mile they travel on foot, either running or walking. Why only 100 kcal?

It equals 100 kcal in both cases because the total work (force x distance) is the same; kcal (heat energy) can be converted into kJ (work energy).

Example:

It might take you 15 – 20 minutes to walk a mile but only ~ 6 – 8 minutes to run a mile. Even though the time increases, the amount of work remains the same!

So, if you are thinking in the terms of work then you need to add 35 – 70 miles (100 kcal per 1 mile) of activity per week, or 5-10 miles per day, onto your regular everyday activity in order to realize a caloric deficit of 3,500 – 7,000 kcal (loosing 1 – 2 lbs/week).

In other words, you would have to run an extra 35 miles per week (5 miles/day) to lose 1lb of body fat or 70 miles per week (10 miles/day) to lose 2lbs of body fat.

At the same time you wouldn’t be able to eat any additional food! So, you have to run at least 5 miles a day but you can’t eat more food.

How realistic does losing 2 lbs of body fat/week sound to you without pharmaceutical intervention?

Recommendations For Losing Fat In-Season & Off-Season

Losing body weight during the season should be avoided because you also lose energy reserves.

During the season you need to stay away from ”empty calories” and instead follow a high-carbohydrate/low fat diet. This diet is more beneficial as the athlete can increase muscle mass while decreasing % body fat.

During the off-season training emphasis might shift to losing body fat. In order to lose body fat effectively you should:

  1. engage in a resistance training program
  2. commit to aerobic training
  3. follow a balanced diet that provides little simple sugars but more complex carbohydrates

Related Sports Nutrition Articles

Losing Weight: How To Do It & Get In Shape
Ideal Tennis Player Body: Lean Mean Machine
How Sports Nutrition Can Impact Your Performance
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