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No, A Glass of Wine Doesn’t Equal 1 Hour of Exercise

Wine (Wikipedia)

In this week’s post I return to my roots and highlight some new reporting that doesn’t quite do justice to the reality of a scientific study. It all began when I saw a Facebook link to an online article entitled “Drinking A Glass Of Red Wine Is The Same As Getting An HOUR OF EXERCISE, Says New Study and Our Wildest Dreams.” You can view the original Bustle.com web article here. But when you view it, you can see that it is actually citing another second-hand source (found here) with even less information. Both articles have very misleading titles. The articles note that the authors of the scientific study, Dolinsky et. al, 2012, have claimed an antioxidant compound in wine (resveratrol) can yield similar benefits to exercise. And yet the title of both articles suggests drinking wine was examined in the study. So, let’s directly examine the Dolinsky et. al study, which actually was published two years ago I might add (despite both web articles posting about the study within the past few months).

The Takehome: It’s possible that a glass of wine equals an hour of exercise, but the Dolinsky study didn’t ask that question, so such a claim has no basis in regards to this work. The study looked at one compound in wine (resveratrol) and found that treating rats with resveratrol results in a variety of physiological changes that are also found after exercising. While some “exercise effects” of resveratrol occurred when the compound was given to rats that were not exercise trained, the majority of the data in this study looks at the effects of resveratrol on exercise trained rats. As a result, the data in the paper make a stronger case for resveratrol improving aspects of health & fitness (insulin and glucose sensitivity, time to exhaustion, fat oxidation) in rats that were previously exercised trained. So, this study is more applicable to an athletic population, not a sedentary one. Still, the improvements noted are not entirely clear-cut. For example, although cardiac function was improved by resveratrol in several ways, it was not improved in one of the most sought after ways – cardiac output. The effects of exercise on the human body are vast and this study suggests resveratrol can duplicate some of them, but not all. And as for wine, we can only speculate.

STUDY DETAILS:

The Experiment:

  • Male rats were used as a model for humans in this study.
  • 4 g of resveratrol per kg body weight per day was administered to rats in their food.
  • Initial exercise training was 60 minutes of daily, forced treadmill running (speed increased progressively during sessions) for 5 days/wk. Total duration of the training was 12 weeks.
  • Exercise testing was performed using a series of forced treadmill running bouts to exhaustion. A control group of rats was handled similarly, but did not receive any exercise training.
  • A variety of outcome measures were assessed in addition to time to exhaustion: Muscle force production, left ventricular wall stress, glucose and palmitate oxidation rates (from isolated heart tissue), glucose and insulin tolerance, gene expression analysis of isolated heart tissue.

The Results:

  • Rats supplemented with resveratrol had significant improvements (~25%) in time and distance to exhaustion whether they had exercise training or not.
  • Comparing only the rats who had exercise training, those given resveratrol had increased exercise performances of around 20%.
  • Muscle (tibialis anterior) twitch force was greater (~18%) in resveratrol treated rats who exercised compared to exercisers without resveratrol. A similar result was found in the soleus muscle (~58% increase in twitch force).
  • Exercised rats given resveratrol had significanly improved left ventricular (blood) ejection fractions compared to those without resveratrol, but heart rate and cardiac output was unchanged.
  • Insulin and glucose sensitivity were improved and oxygen consumption increased in exercised rats given resveratrol compared to those who were not.
  • Analysis of excised (removed) heart tissue indicated resveratrol enhanced certain markers of fat oxidation/metabolism in exercise-trained rats.

The Limitations:

  • Male rats were used in this study and the results may not be applicable to male and female humans.
  • Intact heart rate and cardiac output measurements were conducted under anesthesia.
  • Cardiovascular measurements from excised heart tissue do not entirely match changes observed in the intact animals.
  • Cardiovascular measurements from excised heart tissue indicated enhancements in only some markers of fat oxidation/metabolism; free fatty acid and cardiac triglyceride levels were not altered by resveratrol treatment.
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  • Interesting but I’m not a drinker. Guess I’ll have to stick with training (not a bad thing). Great post and awesome site.

  • W341

    You forgot that the dose of resveratrol given is impossible to get from drinking red wine (without killing yourself many times over), making the entire study totally worthless. The bloggers who sensationalized this completely made up the connection between a glass of wine and an hour of exercise, neither of which are mentioned at all in the original article.

  • Good point. Most animal studies are problematic in their doses when compared to human intake levels.

  • Thanks G.A. Page!

  • W341

    You say “problematic” and I say “totally full of crap.” They choose the insanely high doses because those are the doses required to have an effect. Even if you calculate a “human equivalent dose,” (see Reagan-Shaw et al 2007 in FASEB for a calculation if you are unfamiliar, which I was until recently) the dose in this study equates to 850 glasses of Spanish red wine per day (from a red wine having a very high concentration of ~1.89 mg per glass on a 150 lb basis). As conducted it has absolutely no relevance to human health. You made plenty of other good points, but this point alone should completely negate any impact of this study. IMO, it should have never been published with the language it contains (and that is a serious, but common failing of peer review)