When is the best time to exercise?          One of the most frequently asked fitness-related questions is “what is the best time of day to exercise?” And my usual answer? Whatever time suits you best! Seriously, I don’t believe in prescribing a specific time to exercise because everyone’s routine is different, and whilst working out early morning may suit some people, it certainly won’t suit everyone. Inevitably, evening time is the most convenient time for people to fit exercise into their routine. Scientifically, the jury is still out as to the best time of day to exercise. There are a number of theories out there, so let’s explore them, and then I’ll leave it up to you to decide what works best for you. First of all, let’s talk a little bit about circadian rhythms, the daily cycles that our bodies follow. These rhythms originate in the hypothalamus in the brain, and regulate everything from body temperature and metabolism to blood pressure.          The rhythms result from the firing rate of neurons. They have conformed to our 24-hour light-to-dark cycle, and may be regulated and re-regulated each day according to the environment. It is the influence of circadian rhythms on body temperature that seems to yield the most control over the quality of a workout. When body temperature is at its highest, your workouts will likely be more productive; when your temperature is low, chances are your exercise session may be less than optimal. Body temperature is at its lowest about one to three hours before most of us wake up in the morning, in contrast to late afternoon when body temperature reaches its peak. Studies have consistently shown that exercising later in the day produces better performance and more power. Muscles are warm and more flexible, perceived exertion is low, reaction time is quicker, strength is at its peak, and resting heart rate and blood pressure are low. Recent studies at Cambridge University have shown that muscle temperature and other physical parameters reach a peak in the later afternoon, so between 4 pm and 6 pm is probably the ideal time to go to the gym. But that’s not a very convenient time for most working people in this country! Psychologically, too, we often find it easier to tackle workouts later in the day, and studies have shown that evening exercisers are more likely to stick to their routines for longer. Another train of thought is that exercising first thing in the morning will boost the metabolism, and also make you eat less during the day. A recent study carried out at Loughborough University in England, a renowned centre for the research of sport and exercise science, found that a good workout in the morning could prevent snacking later in the day. Exercisers who ran for 60 minutes at about 70 percent of their maximum effort (70% Max Heart Rate) before breakfast reported less hunger for two hours after eating, compared with those who did not exercise before the same meal. The researchers concluded that intense training may suppress an appetite-fuelling hormone, ghrelin, so you're less tempted to snack in between meals. Though training at any time of day will raise performance levels, research has shown that the ability to maintain sustained exercise is adaptive to circadian rhythms. In other words, consistently training in the morning will allow you to sustain exercise during a morning marathon longer than if you train in the evening. Regardless of any of these findings, I think we can all agree that exercise at any time of day is better than no exercise at all. No matter what time of day we exercise, the benefits are there for the taking – weight loss, stress relief, energy boosting, reduction of blood pressure and cholesterol, and generally feeling better about yourself. If you are a regular exerciser, you will have already determined your most productive time to exercise and you should continue to follow the routine that works best for you. If you are new to exercise, think about your daily routine, and when the most suitable time for exercise would be for you. Try exercising at different times of the day if you are unsure of what suits you, and you’ll soon discover what best fits your routine. Some people who have more flexible jobs or more free time might even like to split up their exercise throughout the day – you could exercise for 15 minutes in the morning, 15 minutes around midday or early afternoon, and 15 minutes in the evening. Just remember – some exercise is better than no exercise at all!