by Dr. Meenakshy Varier on  February 21, 2017 at 12:08 PM Health Watch
  • Though regular, moderate exercise has numerous beneficial effects on the body, intense workout can make the immune system vulnerable to infection and illness.
  • New study suggest that consuming carbohydrates during or straight after an intense workout may be helpful, as it can improve the health of the immune system.
  • The findings will particularly be helpful for athletes, who engage in intense workouts multiple times a day.

Eating Carbs During Intense Exercise Offers Protection Against Infection
Consuming carbohydrates during, or immediately after, an intense exercise can help the immune system recover.

The study, conducted by researchers at the Queensland University of Technology, was published in the Journal of Applied Physiology.

Exercise leads to complex changes in the body such as rapid heart rate to pump oxygenated blood to the muscles, drop in blood sugar levels, breaking down and growth of cells. These changes are beneficial to the body and mind.

According to CDC guidelines, the exercise recommendations for adults 18 years and older are:
  • 150 minutes of aerobic activity of moderate intensity every week, such as brisk walking
  • muscle-strengthening activities on at least two days every week, as part of which all major muscle groups should be targeted
  • 75 minutes of high-intensity aerobic activity (such as jogging) are recommended weekly
But according to data from the CDC, only 49% of the population 18 years of age and older meet the Physical Activity Guidelines for aerobic physical activity, and only 20.9% of the same population meets the guidelines for both aerobic exercise and muscle-strengthening activities.

Effect of Exercise on Immune System

Regular moderate exercise improves the immune system offering protection against ailments such as the common cold, but intense exercise done regularly increases the risks of suffering from upper respiratory illness.

This is because, it is believed that there is an "open window" where the immunity is weakened and intense exercise during this period increases vulnerability to illness and infection.

Intense exercise can be a source of stress to the body and creates more physiological stress, which causes physiological and biochemical changes in the body.

To tackle these changes, the immune cells may simply move out of the blood stream to the lungs, for example.

This is especially true among those who engage in intense workouts or endurance athletes who work out for 90 minutes or more.

Therefore, proper recovery is necessary to prevent "overtraining syndrome", where the person feels fatigued instead of feeling better from exercise.

Benefits of Consuming Carbs

Researchers suggest that consuming carbohydrates during or straight after an intense workout may be helpful, as it can improve the health of the immune system.

"Among various nutritional strategies to counteract immune depression during exercise recovery, carbohydrates have proven the most effective. Ingesting carbohydrates during vigorous exercise may help, because carbohydrates maintain blood sugar levels." said lead author Dr Jonathan Peake.

"Having stable blood sugar levels reduces the body's stress response, which in turn moderates any undesirable mobilization of immune cells. However, more research is warranted to verify that this also helps to prevent infections and illnesses." Peake added.

Researchers also suggest that the immune cells do not always makes the body vulnerable to infections and may instead move around the body during recovery, patrolling for where they are needed.

"People often have fewer natural killer white blood cells after a workout but we now believe they move to other parts of the body, rather than being destroyed," he explained.

Carb Recommendations

"Between 30 and 60 grams of carbohydrates every hour during exercise help to support normal immune function. Examples of carbohydrates that could be consumed during exercise include carbohydrate-containing fluids, gels and bars consisting of different carbohydrates such as glucose and fructose. Alternatively, bananas may also do the job," noted Dr. Oliver Neubauer, also the lead author of the research.

Consuming carbohydrates in the first few hours immediately after strenuous exercise also helps to restore immune function. This is especially important in situations where the recovery duration between two consecutive exercise sessions is short, which is often the case for athletes.

Apart from consuming carbs, a well-balanced diet in general is necessary to help maintain immune function following longer-term exercise training.

Sleep is another important aspect for maintaining immune function, though more research is needed to understand the influence of sleep on immunity in athletes.

"Current knowledge about changes in immune function during recovery from exercise is derived from assessment at the cell population level of isolated cells ex vivo or in blood. This assessment can be biased by large changes in the distribution of immune cells between blood and peripheral tissues during and after exercise," noted the study.


  1. Jonathan Peake et al. Recovery of the immune system after exercise. Journal of Applied Physiology; (2016) DOI: 10.1152/japplphysiol.00622.2016

Source: Medindia

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