What happens when you do two workouts a day?

With summer here and life slowly returning to normal, you can finally wear those lockdown purchases that have been sitting in your wardrobe since 2020. 

But, if you've let your fitness routine slip in the past year (61-percent of Americans gained weight during the pandemic, as reported by the American Psychological Association Survey), you might be feeling the pressure to tone up and slim down.  

After all, who doesn’t want to feel confident in the best summer dresses after the year we’ve all had? Doing two workouts a day might just be the solution you're looking for, but what happens when you double your exercise sessions, and what factors should you consider? Our fitness experts have the answers.

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What are the benefits of two workouts a day?

Doing one workout might seem taxing enough but personal trainer Mark Fox from The Training Room, the UK's leading health and fitness education provider, explains how doubling up can improve your fitness:

1. Fast-track your goals: Performing two workouts in a day can boost your calorie burn if you’re trying to lose weight. If you’re training for a sporting event, or want to get stronger, it can also increase muscle mass.
   
2. Focused training: When performing two workouts a day, you’re able to divide training up into specific elements. For example, cardio in the morning and weights in the afternoon. With a good amount of recovery in the day, you may be able to work harder in each individual session compared to doing them together.
   
3. Flexibility: If you’re strapped for time and can’t commit to a full session, completing the full workout in two shorter sessions might take some pressure off your schedule.
   
4. Afterburn: Workouts help increase our metabolic rate during exercise and for a short period of time afterward, so doing two workouts in a day could mean you get twice the benefit. 

What are the drawbacks of two workouts a day?

As with any new workout routine, it’s important to know the potential risks. Personal trainer Siri Anderson, from UK-based Human Health by The Clinic, explains the drawbacks you need to consider before committing to a more vigorous routine:

1. Overexertion: There is such a thing as overtraining, which can leave you prone to low energy levels or fatigue.
   
2. Increased risk of injury: This is especially true if you are not planning your exercises with the help of a specialist, such as a personal trainer.
   
3. Increased stress levels: Overtraining can negatively impact stress levels and hormone regulation, both of which have a host of negative long-term implications, such as a weakened immune system.
   
4. Lack of recovery time: This can increase risk of injury. You would need to leave at least six to eight hours of rest in between each session to give your muscles and nervous system a chance to reset.

If you do two workouts a day, do you need to eat more?

“If performance is your goal, like increasing aerobic fitness/endurance, building muscle, etc., you’ll need to increase your overall calorie intake to keep up with the demands of the increased routine,” says Mark Fox. 

“If you’re completing two workouts in a day to help you lose weight, ideally, you want to try to keep the calories below what you actually burn in a day. It's a delicate balance of eating enough so you have the energy to train but not too much that you’re not in a calorie deficit.”

How to prevent injury if you do two workouts a day:

“It is advised against going ‘from zero to hero’, as this is a sure-fire way for this workout routine to backfire, so a steady increase in the frequency of workouts is always recommended,” says Siri Anderson. 

“If someone’s goals justify two workouts a day, it would be a good idea to think variation to avoid injury. A good example would be to do a more strenuous workout in the morning (e.g. a run, a HIIT class, or doing heavy lifts), with a more restorative workout to downregulate in the evening (e.g. a yoga class, mobility, or stretching).” 

If the goal is to increase muscle mass or train for a specific event, then it’s best to create a more specific program with a personal trainer. 

Should you avoid two HIIT workouts a day?

“Doing two HIIT sessions in a day would be taxing for most people, so it would be recommended to go for a high-intensity + low-intensity combination if you were to do two workouts a day,” says Anderson. 

“Any exercise, particularly high-intensity sessions such as HIIT, increases your stress hormones adrenaline and cortisol. Whilst they have a positive role to play to ‘get up and go’ in exercise, getting into a steady state of high-stress hormones can have several negative implications, such as sleep disruption, increased abdominal fat, and increased blood pressure.”

So plan your workout schedule accordingly!