Last verified October 2026

Fusion Protein Raspberry Citrus shot on a kitchen counter next to a mug of coffee and a folded gym towel on a rest day morning
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Quick answer: Yes, if you need it to hit your daily protein target. It comes down to your total daily intake, not whether you trained that day. A shake or shot on a rest day is simply a convenient way to close the gap when your meals fall short.

Should you drink a protein shake on rest days? It comes down to your total daily intake rather than whether you stepped into the gym that day. Your muscles don't stop recovering the moment you rack the weights. Muscle protein synthesis can stay elevated for up to 24 to 48 hours after a workout. Drinking protein shakes on rest days is simply a convenient way to bridge the gap when your meals fall short, so your body has the raw materials it needs to repair and build tissue on your off days.

24 to 48 h
how long muscle protein synthesis can stay elevated after resistance training, a bit less in people who train regularly
1.6 g/kg
(0.7 g/lb) the average daily intake where muscle gains level off, with some people benefiting up to 2.2 g/kg
21g
of protein in a single Fusion shot, ready to drink with zero mixing on your off days

Sources: MacDougall et al., 1995; Damas et al., Sports Medicine, 2015; Morton et al., British Journal of Sports Medicine, 2018.

Your Muscles Don't Take the Day Off

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Muscles don't grow while you lift. It's a common misconception that muscles grow while you're lifting weights. In reality, your workout is the signal. The actual rebuilding happens in the hours and days after you leave the gym.

So, do you need protein on rest days? Yes, because that recovery process takes time. Research shows that muscle protein synthesis (the process of repairing and building new muscle tissue) rises sharply after resistance training and can remain elevated for up to 24 to 48 hours, a bit less in people who train regularly (MacDougall et al., 1995; Damas et al., 2015).

During this window, your body pulls amino acids from the food and supplements you consume to repair and build muscle tissue. Prioritizing protein on rest days gives your body a steady supply of those building blocks right when recovery is peaking. If you cut back on your intake the day after a workout, you leave your muscles short on the exact materials they need to finish the job.

How Much Protein Do You Need on a Rest Day?

Your target for how much protein on rest days is the same as it is on your training days. You don't need to drop your intake just because you aren't going to the gym. Since your muscles are still repairing themselves from yesterday's session, keeping your daily protein consistent is the simplest way to support recovery.

A landmark meta-analysis published in the British Journal of Sports Medicine found that to maximize muscle growth and strength from resistance training, you should aim for about 1.6 grams of protein per kilogram of body weight (or roughly 0.7 grams per pound) each day (Morton et al., 2018). For most active people, the International Society of Sports Nutrition (ISSN) recommends a general daily range of 1.4 to 2.0 g/kg (0.6 to 0.9 g/lb) (Jäger et al., 2017).

Here's what that 1.6 g/kg (0.7 g/lb) daily target looks like across different body weights:

Body weight (lb) Body weight (kg) Daily protein target (1.6 g/kg)
130 lb 59 kg ~95 g
150 lb 68 kg ~110 g
170 lb 77 kg ~125 g
190 lb 86 kg ~140 g
210 lb 95 kg ~150 g

Rounded to the nearest 5 g. Same target on training days and rest days.

When a Protein Shake Makes Sense on a Rest Day

Taking a protein shake on off days makes the most sense when you use it as a simple gap-filler. On days you don't train, your routine often looks different. Maybe you sleep in, eat smaller meals, or don't have your usual post-workout appetite. That makes it surprisingly easy to fall short of your daily number.

Overhead view of fried eggs on toast and a chicken salad wrap, with a Fusion Protein Tropical shot on the table

Here's a quick example of how the math works for a 170 lb (77 kg) person aiming for 125 g of protein:

Meal What they ate Protein
🍳 Breakfast 2 eggs and toast 15 g
🌯 Lunch Chicken salad wrap 30 g
🐟 Dinner Salmon, rice, and vegetables 35 g
🥣 Snacks Greek yogurt and almonds 25 g
Total from food 105 g
The gap 125 g target minus 105 g from food 20 g short

Instead of cooking another meal when you aren't hungry, a quick supplement bridges that gap. This is where protein shots fit naturally into a rest day. A single Fusion shot in Fruit Punch or Raspberry Citrus gives you 21 g of protein in a light, ready-to-drink format. There's no heavy milky texture, no blender, and no shaker bottle left sitting in the sink on your lazy day.

Fusion Protein ready-to-drink protein shot flavour range, Raspberry Citrus, Tropical, and Fruit Punch, each with 21g protein
Shop Fusion Protein →

When You Can Skip It

If your regular meals and snacks already cover your daily protein target, you don't need a shake or a shot at all.

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Food already covers it?

Supplements aren't magic. Extra protein on top of a diet that already hits 1.6 g/kg (0.7 g/lb) won't speed up recovery or build extra muscle (Morton et al., 2018). If you're cooking big meals or eating plenty of chicken, fish, eggs, tofu, or Greek yogurt, you're covered.

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Coming up short?

Save your shots for the days when your schedule is busy or your food intake comes up short. To balance supplements with your meals across the week, see our guide on how many protein shots you should drink per day.

Best Time for Protein on a Rest Day

On a rest day, you don't need to worry about post-workout timing windows. Your total daily intake is still the top priority, followed closely by how you pace that protein from morning to night.

Rather than eating a tiny amount of protein at breakfast and trying to cram 80 grams into dinner, aim to spread your intake evenly across 3 to 4 meals or snacks, spaced every three to four hours. The International Society of Sports Nutrition recommends aiming for roughly 20 to 40 grams of protein per serving (or about 0.25 to 0.40 g/kg per meal) to consistently stimulate muscle protein synthesis throughout the day (Jäger et al., 2017; Schoenfeld & Aragon, 2018).

If your lunch or afternoon snack is light on protein, a 21 g shot is an easy way to keep that steady rhythm going without extra meal prep.

Before bed on a rest day

If you look at your totals after dinner and realize you're still 20 grams short of your daily target, taking your protein before sleep is a smart move. Research shows that protein consumed before bed is effectively digested and absorbed overnight, providing a steady stream of amino acids to support muscle recovery while you sleep (Trommelen & van Loon, 2016). For a full breakdown on overnight recovery and how to time it, read our guide on having a protein shake before bed.

Frequently Asked Questions

Will a protein shake on a rest day make me gain fat?
No, a protein shake won't cause fat gain on its own. Weight gain comes down to your total calorie balance over time, not a single food or supplement (Hall et al., 2012). You only store extra body fat if you consistently consume more total calories than you burn. As long as your shake or 21 g protein shot fits into your daily calorie target, it simply counts toward your protein for the day.
Should I eat less protein on rest days?
No, you should keep your protein target the same on rest days as on training days. Because muscle protein synthesis can stay elevated for up to 24 to 48 hours after a workout, your body is still actively repairing muscle fibres on your off days (MacDougall et al., 1995; Damas et al., 2015). If you need to eat fewer calories on days you aren't burning as much energy, it's better to slightly trim your carbohydrates or fats while keeping your daily protein steady around 1.6 g/kg (0.7 g/lb) (Morton et al., 2018).
Can I drink a protein shake on a rest day if I'm trying to lose weight?
Yes, keeping your protein intake high on rest days is one of the best strategies when you're in a calorie deficit. Research shows that eating plenty of protein while losing weight helps preserve your lean muscle mass so that the weight you lose comes primarily from fat (Hector & Phillips, 2018). Protein also increases satiety more than carbs or fat, which helps keep hunger in check on days you aren't training (Paddon-Jones et al., 2008). A low-calorie protein shot is an easy way to hit your protein goal without burning through your daily calorie budget.
Do I need more protein the day after leg day?
You don't need to raise your daily target above the standard 1.6 to 2.0 g/kg (0.7 to 0.9 g/lb) range, even after a heavy lower-body session. However, hitting your full target is especially important the day after training large muscle groups, and you want to make sure each meal hits a solid protein threshold. One study found that right after a whole-body workout, a 40 g serving of protein stimulated more muscle protein synthesis than a 20 g serving (Macnaughton et al., 2016). Rather than eating a massive surplus the next day, focus on hitting your normal daily target and spreading it across solid 20 to 40 g servings.
Is it bad to skip protein on rest days?
Skipping a protein shake on a rest day isn't bad at all if your regular meals already cover your daily protein needs. However, falling well short of your total daily protein target on rest days can slow down recovery and leave you short on the amino acids needed to rebuild muscle from your previous workouts (Jäger et al., 2017). Missing your target once in a while won't ruin your progress, but consistently under-eating protein on your off days will hold back your long-term strength and muscle gains.

Sources: MacDougall et al., Canadian Journal of Applied Physiology, 1995; Damas et al., Sports Medicine, 2015; Morton et al., British Journal of Sports Medicine, 2018; Jäger et al., Journal of the International Society of Sports Nutrition, 2017; Schoenfeld & Aragon, Journal of the International Society of Sports Nutrition, 2018; Trommelen & van Loon, Nutrients, 2016; Hall et al., American Journal of Clinical Nutrition, 2012; Hector & Phillips, International Journal of Sport Nutrition and Exercise Metabolism, 2018; Paddon-Jones et al., American Journal of Clinical Nutrition, 2008; Macnaughton et al., Physiological Reports, 2016.

Fusion Protein protein shots in Raspberry Citrus, Tropical, and Fruit Punch

Light enough for your lazy day.

21g of protein, 90 calories, zero sugar. No shaker, no blender, no cleanup.

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Our Guides

Should You Drink a Protein Shake Before Bed?

Should You Drink a Protein Shake Before Bed?

Yes, you can drink a protein shake before bed. Whether you should comes down to your total protein and calories for the day. Here is what the research says, how whey compares to casein at night, and how to keep it light enough to sleep well.

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