Fueling for strength training & two-a-days

When considering your fueling needs for running, you should take into account both exercise duration and intensity. It’s an even bigger consideration when you throw strength training into the mix as a standalone session or part of a two-a-day. Whether you’re leaping through plyometric exercises or lifting barbells, kettlebells, and other weights, gym workouts tend to be high intensity. And as you could be using many different muscle groups, you’re going to consume an awful lot of energy in even your shortest strength or power workouts. Going for a run the same day? Now you need even more fuel. 

The trouble I find with many new clients whose gym sessions and two-a-days aren’t working for them isn’t the programming itself; it’s that they only focus on fueling for runs OR workouts and usually aren’t sure how to fuel for BOTH.  Not fueling your body properly for your workouts can lead to short changing your sessions and overall gains. 

Much like with running, gym training requires quick-acting fuel that’s available on demand. This is a prerequisite for rapid muscle contractions – concentric as you shorten the muscle fibers and eccentric while you lengthen them under tension. These kinds of exercises not only require you to move quickly but also powerfully (think the combination of strength and velocity), which recruits a greater number of muscle fibers and takes even more energy. 

A review released via Sports Medicine stated that carbs make “a greater relative contribution to energy production where exercise is of moderate-to-high intensity,” with standard volume strength training depleting glycogen stores by 24 to 40 percent. The authors explained that this can be much higher, referencing a prior study that observed glycogen running out in certain muscle fibers. With this in mind, they concluded that ingesting pre-workout carbs improves performance in high-volume strength workouts lasting 45 minutes or longer and/or when you haven’t eaten for eight hours (such as when you hit the gym first thing in the morning). 

These physiological demands show why it’s essential that you’ve got enough fast fuel available to go into overdrive set after set and rep after rep, like a car getting a nitrous oxide boost in The Fast and the Furious. This means blood glucose first and stored glycogen second, both of which are provided by – you guessed it, carbohydrates. Just like on your runs, fat could potentially be utilized for fuel in your strength training but because it takes so long to access and utilize, it’s unsuited to the task. Instead, plan to top up your gas tank with carbs before you hit the weights, which you could get from a piece of toast, half a bagel or muffin, or a small bowl of cereal. Afterwards, don’t forget your post-workout recovery nutrition of protein + carbs (we will discuss recovery nutrition in future articles).

Some athletes find it challenging enough to dial in their fueling for a single daily workout, so what happens when we throw two-a-days into the mix? If you are not fueling adequately, the answer is often that you end up in a calorie deficit, don’t intake sufficient protein to start the repair process, and consume too few carbs to replenish your glycogen stores for the second session. As a result, you might be sluggish and slow during training and fatigued and sore afterward. 

To avoid this, aim to take in at least 25 to 30 grams of carbs before lifting or running (whatever comes first), and make it more if you’re planning to go longer or harder. If you have hours in between your workouts, you should refuel in between with a combination of carbs and protein with three purposes in mind – replenishing nutrients you just used, beginning the repair process, and fueling up for what’s to come. 

Another review of studies that investigated the link between carb intake and resistance training noted that if “there is another high-intensity workout planned that day for the same musculature, higher carbohydrate intakes up to 1.2 g/kg/h may be warranted to maximize glycogen resynthesis in between workouts.” An International Society of Sports Nutrition position paper suggested “combining carbohydrates (0.8 g/kg/h) with protein (0.2-0.4 g/kg/h)” when there’s less than four hours between workouts. While whole grains and low-glycemic foods are often nutrient rich, they recommended easily digestible ones that are high on the glycemic index when trying to refuel between two-a-day workouts.  

These numbers might seem like they only complicate matters but refueling post-run and pre-lift or vice versa doesn’t need to be tricky. Eat a meal or large snack that includes carbs + protein, such as cottage cheese with fruit, or a buffalo chicken salad sandwich. If you need something quick & easy, try a Shower Shake that also includes protein powder, oats and fruit.  Quantities of carbs and protein is depending on your body size, age & workouts, as well as if your recovery nutrition is a snack or a meal.

In addition to providing more fuel for the physical side of your second workout, fueling in between your two-a-days will help you achieve better cognitive performance. If your blood sugar is too low after the first session, you’ll probably struggle to focus and pay attention during the second one. Whereas if you eat carbs, you’ll be more alert and focused, maintain proper form, and concentrate on cues that can ensure you have a high-quality session. 

If you lift and run back-to-back, take a guess at what our fuel source before each segment is…CARBS! Aim to take 25-30 grams of carbs before your lift and then another 25-30 grams of carb before your run (or more if you are running >70 minutes). See our last blog post for tips and examples.