Quick answer
Take a mass gainer when it helps you add calories without displacing a meal, often between meals or after training. The timing is less important than your daily calorie intake. Start with a portion that fills your actual calorie gap, rather than automatically using the full serving.
Why timing a mass gainer is different from timing whey
A typical whey protein shake delivers 110-130 calories and digests quickly. A typical mass gainer shake delivers 600-1,000 calories with a large carbohydrate load. The caloric density changes the relevant considerations around timing, particularly for digestion and training performance.
The key question for mass gainer timing is not just when amino acids are available to muscle tissue, but when those 600-1,000 calories are most useful and least likely to interfere with training or sleep.
Post-workout: the most common and practical window
The period after training is a sensible time to consume a mass gainer. Glycogen stores are partially depleted, muscle protein synthesis is elevated, and your body is primed to use carbohydrates for recovery. A shake within one to two hours after training serves both the protein and carbohydrate recovery need in one step.
If your session is long or intense, the carbohydrate content of a mass gainer is particularly well-placed here. Muscle glycogen resynthesis peaks in the two hours following training.
Between meals for calorie stacking
For hard gainers who struggle to eat enough at meals, consuming a mass gainer between meals is a practical strategy for increasing total daily calories without needing to force larger portions at the table.
A mid-morning or mid-afternoon shake keeps calorie intake distributed across the day rather than concentrated in two or three large meals. This approach also tends to be easier on digestion than drinking a 900-calorie shake immediately after a full meal.
Before training: use with caution
A mass gainer taken within one hour of training is risky for many people. The large carbohydrate load takes time to digest, and training with a partially digested high-volume shake in your stomach often causes discomfort, bloating or nausea.
If you prefer a pre-workout calorie boost, a smaller whole-food meal two to three hours before training is preferable. If using a mass gainer pre-workout, consume it at least two hours before your session.
Cheapest Mass Gainer
UP YOUR MASS XXXL 1350
MHP · 12 lb
Pros
- The declared portion supplies 7g fibre, alongside its protein
Cons
- At 21.6% protein, a 25g protein portion supplies about 450 kcal, rather than the roughly 100 kcal supplied by the protein itself
Before bed: mostly unnecessary
Some people consume a mass gainer before bed to top up calories at the end of the day. This is effective at increasing total daily calories, but the practicalities are not ideal. A very large calorie load before sleep can disrupt sleep quality, and the fast-digesting carbohydrates in many mass gainers are not a good structural fit for overnight recovery.
If you need more calories at the end of the day, a smaller meal with slower carbohydrates and a casein-based protein source is a better option than a full mass gainer serving.
The practical recommendation
Post-workout is the default best time for most people using a mass gainer. If you cannot fit it around training or if you use it primarily to hit daily calories, between meals is the next best option.
The most important timing consideration is consistency. Taking your shake at the same time each day makes it a habit that sticks and ensures your daily caloric intake is predictable and plannable.
Watch what buyers found
Hands-on opinions
Should Skinny Guys Take Whey Protein or Mass Gainer?
Josef Rakich
A topic-specific video selected for additional practical context on Best Time to Take Mass Gainer: A Smarter Buyer's Guide for 2026.
References
Sources and further reading
- 01
Frequently asked questions
Can I take a mass gainer twice a day?+
If your calorie target requires it and your digestion handles it well, yes. Two half-servings spread across the day is often easier to manage than one full serving. Ensure total daily calorie intake is appropriate for your goals.
Should I take a mass gainer on rest days?+
Yes, if your daily calorie target still requires it. Muscle recovery and protein synthesis continue on rest days. Caloric intake should remain consistent regardless of whether you trained that day.
Can I mix a mass gainer with milk instead of water?+
Yes. Mixing with whole milk adds roughly 150 extra calories, more protein and additional carbohydrates. This increases the total caloric content further, which is useful if you need more calories but may be excessive if you are already hitting your target.