Every year, Ramadan brings with it the dilemma of whether it’s better to workout before or after iftar. Before we get into the technicalities, we need to divide people into 2 groups based on their workout goals: Performance goals (faster, stronger, higher endurance, etc) and weight loss goals.
High intensity can be simply defined as workouts that speed up the heart rate (sprints, soccer, weighlifting, crossfit, etc).
Low intensity is basically low intensity cardio. People who train usually know define it as “endurance activities in zones 1 and 2 where the heart rate does not exceed 150 bpm.”
Group 1 – Performance goals
It all depends on the intensity of the workout.
All high intensity workouts are fueled by glucose (rely mainly on glucose for energy), which is very low in the fasting state. For a person to be able to perform high intensity workouts efficiently, there needs to be plenty of glucose in the body. Therefore, working out after iftar is best for achieving your performance goal through high intensity training; there will be enough glucose in the blood to generate the energy required for the workout.
All low intensity activities depend on fats as a primary source of energy. People who perform low intensity workouts can train before iftar, which is, in fact, a strategy adopted by endurance athletes called “training low”. Training low means training on low blood glucose and depleted glycogen stores. What this does is train the body to utilize fat as a primary source of energy. Endurance athletes use this strategy because they often train and perform for very long, continuous periods of time (3-4 hrs+), and the blood glucose does not last that long. It is important, thus, to have a body that can efficiently oxidize fat for fuel.
Endurance athletes wishing to perform high intensity workouts, on the other hand, should do so after iftar when the blood glucose levels are higher.
Group 2 –Weight loss
Timing of weight loss workouts also depend on the type of activity. Weightlifting, High Intensity Interval Training – HIIT, and other high intensity workouts are best performed after iftar. Again, these workouts require glucose, and blood glucose levels are low in fasting. Performing these workouts after replenishing your body means the performance will be better, and, therefore, more burnt calories.
A 4-week study was performed to analyze the effect of low intensity cardio for weight loss in 2 groups of people: fasting and non-fasting. The 2 groups would fast overnight. The next morning, the former would perform low intensity cardio on an empty stomach while the latter would a drink meal replacement shake before the workout. Both groups followed a caloric deficit diet over the course of the study. By the end of the month, the results showed that both groups lost the same amount of weight regardless of whether they were fasting prior to their workout; no significant difference was shown between the 2 groups.
If you’re an endurance athlete trying to increase your muscle adaptation to oxidize fat more efficiently, then working out before iftar is optimal for you. Be extra careful with your workout conditions, however, as not to cause dehydration. In all other cases, after iftar workouts should be your go-to. If before iftar is the only time you have for a workout, there is absolutely no problem with that. It might not be optimal, but it’s definitely better that not working out at all.