Fitness buffs have probably heard an endless stream of nutrition and diet advice around the gym. Some health faddists follow the Paleo diet, others are vegan and some might fast every other day. The fasting-exercise combination is controversial. Some studies point to benefits of lifting weights in a fasted state, while others recommend eating first. Consult your doctor before radically altering your diet.
When people talk about exercising in a fasted state, they often mean first thing in the morning before breakfast. If you ate dinner at six o’clock the night before, then hit the gym at six in the morning, that’s 12 hours of fasting in between. One Belgian study published in "Journal of Physiology" divided 28 young men into three groups: a control group, one that ate breakfast before vigorous exercise and one that exercised vigorously before eating breakfast. All ate a diet of 50 percent fat and 30 percent more calories than they usually consumed. After six weeks, the control group gained an average of six pounds, the group that ate breakfast before exercising had gained about three pounds, and the group that exercised before eating gained almost nothing. The first two groups had become insulin-resistant. The fasted group hadn’t. This study may look convincing, but the sample size was small and only included young men. Another study showed that alternate-day fasting -- that is, eating every other day -- improved insulin sensitivity and glucose tolerance for men, but not for women. More studies need to be done before drawing definite conclusions.
During the ninth month in the Islamic calendar, practicing Muslims mark Ramadan with spiritual fasting. From dawn until dusk, Muslims eat nothing, refraining even from drinking water. Ramadan falls at a different time every year, but is especially challenging when it occurs in summer; the days are much longer, the opportunities to eat shrink and the heat makes abstaining from water painful. Weight lifting Muslims may question how they will adhere to their workouts. Fitness coach and writer Mehdi Hadim emphasizes the importance of planning. He recommends up to an hour of weight training two hours before breaking your fast, eating plenty and drinking a gallon of water during the dark hours. He suggests limiting yourself to lifting weights, skipping cardio during Ramadan because of dehydration dangers. Be aware that Ramadan often brings sleep deprivation, since people try to eat at least a couple meals during times they would ordinarily be sleeping. You may also experience decreased alertness, agility, speed and endurance.
Other Types of Fasting
Dieters sometimes employ fasting as a weight loss technique. For instance, alternate-day fasting has shown some positive weight loss results and improved fat oxidation. However, people who are on longer term fasts, such as the Master Cleanse detox diet, should be very cautious about exercising. This dangerously low-calorie diet consists of nothing but water, maple syrup, lemon juice, cayenne pepper and laxatives. People often stay on the Master Cleanse for more than a week. Since they are usually trying to lose weight, they often combine fasting with cardio and lifting weights. But severe liquid detox diets can lead to muscle breakdown, rather than increased muscle mass.
If you want to experiment with fasting and lifting weights, stay level-headed. Try lifting in the morning before breakfast and see how you feel. Serious athletes can benefit from occasionally training under less than optimal conditions, such as in a fasted state. While you might not want to compete on an empty stomach, the experience of training under different circumstances can boost your performance. However, if you tend toward compulsive behavior, approach fasting cautiously. Gym buffs are notoriously body-conscious, which can lead to eating disorders such as anorexia. People with anorexia often believe they are pursuing health via exercise and fasting, not realizing their error until they’re very sick.
- Mark’s Daily Apple: Why Fast? Part Five: Exercise
- Journal of Physiology: Training in the Fasted State Improves Glucose Tolerance during Fat-Rich Diet
- Strong Lifts: Ramadan & Weight Lifting: How to Maintain Muscle & Strength
- Alan Aragon: An Objective Look at Intermittent Fasting
- NBC News: Experts Warn of Detox Diet Dangers
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