Introduction

We already know for a long time that exercise is an effective treatment for migraine. Last year, we released this blog post, revealing the underlying mechanisms of exercise. The evidence then, as you can see, did not specifically pinpoint one particular mode of exercise as the best. When comparing high-intensity training to moderate continuous training, the former led to more pronounced reductions in migraine days. Strength training in migraine has also proven its efficacy. However direct comparisons (so-called head-to-head comparisons) between the different types of training are not available to date. This study did a network meta-analysis, which gives the opportunity to compare multiple interventions with indirect comparisons. This allows the reader to know what intervention may be more efficacious at one glance, without the need to wait for direct comparisons between different interventions to be studied. More importantly, this type of comparison also allows us to rank the efficacy of the different interventions to know which one is better.

Methods

Articles were searched in Web of Science, PubMed, and Scopus using a combination of keywords related to migraine and exercise. Controlled clinical trials that included exercise as an intervention and compared it against no intervention or usual care were eligible. The studies had to report the monthly frequency of migraine at the beginning and at the end of the intervention. Participants in the studies had to be at least 18 years old and suffered from episodic or chronic migraine.

Results

In total, 21 articles were included in the network meta-analysis, summarizing the evidence from 1195 migraine patients in total. The sample was on average 35.5 years old and included mostly women (female-to-male ratio was 6.7 to 1). Nine of the 21 studies included chronic migraineurs. It was possible to make 27 pairwise head-to-head comparisons between interventions and 8 interventions were indirectly compared.

Interventions studied included strength and resistance training, moderate-intensity aerobic exercise, and high-intensity aerobic exercise and these were compared against one another or against placebo, topiramate, or amitriptyline. The interventions studied had a duration of mostly 8 weeks (40%) and 12 weeks (40%). Every workout included a 10-20 minute warm-up and cool-down period and in some cases, stretching was performed before and after the workout.

Strength training in migraine patients was typically performed for 12-15 repetitions at 45-60% of 1RM, 3 times per week and progressed by adding 5% of the 1RM each week to reach a target of 75-80% of 1RM with 3 sets of 8-10 repetitions by the end of the training program.

The moderate-intensity training protocols started at 45-70% of the VO2 max or 60-80% of the maximal heart rate. This training was conducted 3 times per week and progressed weekly. The high-intensity aerobic training programs were initiated at 55-60% of the VO2max, were performed 2 to 3 times per week, and increased in intensity by 5-10% of the VO2max every week to reach a target intensity of 80-90% of the VO2max as well as a 90-95% of the maximal heart rate at the end of the study period. The studied aerobic activities included running, cycling, jump rope, and home-based aerobic exercise.

The network meta-analysis revealed that, compared to placebo, strength training in migraine had the highest efficacy. It had the potential to reduce the monthly migraine frequency by 3.55 days. High-intensity aerobic exercise training was the second most effective intervention and reduced the monthly migraine days by 3.13 days, followed by moderate-intensity aerobic training which was able to reduce the migraine frequency by -2.18 days. The efficacy of medication to reduce the monthly frequency of migraine, compared to placebo was less than the efficacy of the active training interventions mentioned above. Topiramate could reduce migraine days by 0.98 days per month. Remarkably, although not significant, amitriptyline did not reduce but increased the monthly frequency of migraine as the mean difference was 3.82 (range between -1.03 and 8.68).

Questions and thoughts

Strength training appears to be the most effective treatment option to reduce the monthly migraine frequency burden. At first, strength training in migraine may seem odd for some. Maybe your patient will have fears that the loads will increase tension around the muscles and that this will predispose them to increased complaints. You can advise them that flare-ups are possible in the first weeks of training, but try to explain that these are normal protective strategies of the body to deal with the adaptation. Importantly, loads need to be individualized and progressions are to be made within the individual based on his or her achievements. The authors indicate that regularity of strength training is the key to success, and not necessarily the volume or exercise intensity. As health professionals, our goal is ultimately to get the person moving and adopt a healthy lifestyle. We know that migraineurs often cancel activities due to a headache episode. You can frame the importance of participation in strength training in light of a general improvement in health. Strength training is a method that proven to reduce migraine days by 3.5 days per month. Next to this, active recovery days are advised to be scheduled as well. On these days, your patient is advised to do some lighter physical activities, for example, commuting by bike. Overall, your goal is to enhance their capability and give them back control over their lives. Furthermore, such an enhancement is not only beneficial for their migraine. It also helps with frequently associated comorbid disorders such as obesity, depression, and insomnia.

Talk nerdy to me

An important portion of the included studies was of low risk of bias (85%), meaning that the evidence depicted here gives an almost robust idea of the true effects of the studied exercise modes. A relevant side note is to be placed that of the 21 studies originally included in the network meta-analysis, 6 presented results from a per-protocol analysis. It should be noted that this type of analysis looks at the people who completed the study as it was planned. This may give an idea of what results would look like when a patient has a good adherence to the program. However, it doesn’t take into account the people who did not complete the study’s procedures, for whatever reason. One might for example have an increase in their migraine complaints and decide to quit the strength training program delivered by the study. Those who are experiencing the benefits of strength training will likely be more compliant and adherent to the procedures and will likely report more benefits. With the per-protocol analysis, however, the drop-out isn’t incorporated into the results and this might give a distorted view of the true effects. You can also see that the per-protocol analysis is susceptible to higher overall bias, which is driven by missing outcome data and issues with randomization. So here, it would be necessary to view the outcomes of the intention-to-treat analysis separately from the outcomes of the per-protocol analysis to have a clear picture of what could have been the influence of the issues mentioned above on the overall outcome. Unfortunately, this subdivision is not presented in the current study. Luckily, the majority of studies used the recommended intention-to-treat analysis.

There were no statistically significant differences between the direct (pairwise) and indirect (NMA) efficacy estimates in all comparisons. The studies fitted well in the model and there was only minimal inconsistency in the results. These aspects increase confidence in the results found.

Take home messages

Strength training for migraine was the most effective intervention, followed by high- and moderate-intensity aerobic training. Strength training interventions had the potential to reduce the frequency of migraine by three and a half days per month. This type of training involved strengthening the major muscles of the neck, shoulder girdle, and upper limb. A combination of resistance training with active recovery days in between may provide the most robust way to counter migraine.

Reference

Woldeamanuel YW, Oliveira ABD. What is the efficacy of aerobic exercise versus strength training in the treatment of migraine? A systematic review and network meta-analysis of clinical trials. J Headache Pain. 2022 Oct 13;23(1):134. doi: 10.1186/s10194-022-01503-y. PMID: 36229774; PMCID: PMC9563744.