I talk about exercise in most of my articles as I believe it is one of the key factors to good health and long life. The list of potential effects of exercise could take up most of my space but include improving cholesterol, blood pressure, diabetes, polycystic ovarian syndrome, depression, sleep apnoea, sleep, arthritis, immune health, and how you look and feel. Most people know they should exercise but may be unsure about a few facts. Here I will attempt to answer some of the more common questions about exercise in relation to weight loss.
How much do I need to do? It has been found that doing at least 150 minutes of exercise in a week will have the best results for weight loss. The duration is more important than the intensity.[i] This is because the longer you exercise the more fat you will burn. The body stores carbohydrates in muscle as glycogen. This muscle glycogen is used for energy in the first 20-30 minutes of exercise. Between 30-50 minutes the body starts to use fat for energy. At the transition point is when many people start to feel tired. If you push through this feeling and do 50 minutes of moderate intensity exercise 3-4 times a week you will get the best results.
When should I exercise? Many people believe that exercising in the morning is the best time to get the best results. Although this may bring slightly better results, time of day is less important than just getting out there. The best time is the time that fits into your schedule.
Should I eat before I exercise? The best results can be achieved with exercise on an empty stomach. This will burn more fat, deposit more protein on the muscle and improve insulin sensitivity. [ii] Not everyone can exercise without eating first though. If you feel lightheaded during exercise make sure you eat something first but just keep it small such as a piece of fruit.
Should I eat after exercise? Yes! This is the most important meal of the day. If you don’t eat then cortisol levels continue to rise leading to muscle breakdown, immune suppression and insulin resistance. Your body also needs to replenish the glycogen it used so that you can exercise next time. The best time to eat is within 30 minutes of exercising. [iii]
What should I eat after exercise? This is your chance to eat carbohydrates! Eat at a ratio of 3:1 carbohydrates to protein [iv] (this ratio is ONLY for post exercise). Have some fruit or low GI grains with a good protein source. Most protein powders will have a good ratio of protein to carbohydrates.
I’ve hit a plateau. What do I do? As a person loses weight they need less energy to move around so they burn fewer calories. If you have hit this point it means you need to step up your exercise. You need to either exercise longer or increase the intensity. Trying a different form of exercise can often be helpful too.
If you have indulged lately, kick up the exercise level to compensate. The weather is gorgeous lately, so get out there and get your body moving!
[i] Chambliss HO. Exercise duration and intensity in a weight loss program. Clin J Sports Med. 2005 Mar; 15 (2): 113-115.