Reply from Lasse Gliemann, Jakob Schmidt, Jesper Olesen, Rasmus Sjørup Biensø, Sebastian Louis Peronard, Simon Udsen Grandjean, Stefan Peter Mortensen, Michael Nyberg, Jens Bangsbo, Henriette Pilegaard and Ylva Hellsten

Abstract

We would like to thank the authors for the interest in our study and for the kind positive remarks regarding the study per se. Our understanding of the Letter is that there is a concern regarding over interpretation of the data. Firstly, the title of our study ‘Resveratrol blunts the positive effects of exercise training on cardiovascular health in aged men’ expresses our overall interpretation of the study. We do not find that there is ‘sensationalism’ in this title; in fact it rather well describes the findings in our study. In general, our intention was not to dramatically present our data but to emphasize our observations and it is our opinion that we have done so in an appropriate manner. It is true that resveratrol supplementation did not abolish all of the training induced positive effects on cardiovascular parameters but we found it remarkable how many of the adaptations were absent or blunted in the resveratrol group. It is also true that not all effects of exercise training during a period of only 8 weeks are large and thus the difference between the resveratrol and the placebo groups will correspondingly not be very large. Therefore it is even more remarkable that so many differences were observed between the groups. The authors of the Letter to the Editor propose that we have over-interpreted the statistics. We have re-run the statistics with the more conservative Holm-Sidak post hoc test and found that it does not change the outcome. The effect of resveratrol was not solely observed on a single or a couple of the cardiovascular parameters but on a number of them and thus the possibility of all of the differences being explained by type 1 errors appears unlikely. Thus, we maintain that our findings show that resveratrol can blunt many of the positive effects of exercise training on cardiovascular health parameters. The Letter to the Editor states that the difference in improvement in was not of clinical relevance. The current study did not have a specific clinical focus, but clearly reducing the improvements in maximal aerobic power in a training period due to concomitant resveratrol intake is not attractive, neither for healthy individuals nor in a clinical setting. As evident from Fig. 1 in our paper, the data showed some of the clearest blunting effects of resveratrol. We would like to emphasize that, as with all original research articles, the conclusions made in our article were based on the results included and are not necessarily valid in general, for other dosages of resveratrol, other population groups, etc. Thus, we do not disagree with the argument in the Letter to the Editor that larger amounts of resveratrol, corresponding to doses given in experimental studies on animals, could have had different effects. It should be stated though that the dosages that are given to laboratory animals are much above what has been determined in safety assessments as safe for humans. In summary, the current study was conducted to evaluate the role of exercise training on cardiovascular health in aged men and to elucidate whether resveratrol supplementation would optimize the training induced effects. In contrast to what we expected, our findings showed that resveratrol supplementation had negative effects on several of the observed training induced improvements. We are hoping that our observations will contribute to the understanding of the effect and underlying mechanisms of physical activity on cardiovascular health. More studies are needed to throw further light on the role of resveratrol for cardiovascular health and exercise training effects in humans. An important aspect would be to clarify whether increasing the dose of resveratrol would actually potentiate the effect of exercise training or further blunt the training adaptations.