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The Best HIIT Exercises To Enhance Muscle Growth

2nd February 2023

2nd February 2023

By Beth Shelper

If muscle growth is your fitness goal, you’re in the right place. HIIT workouts are a great technique for burning fat whilst still maintaining and gaining muscle mass, hitting multiple goals at once. These workouts are great for toning up and increasing your stamina.

What are HIIT workouts?

HIIT (high intensity interval training) workouts are a method of exercise that prioritise speed and intensity. You may have heard of techniques such as Tabata, which breaks down these HIIT exercises into timed intervals.

People love HIIT workouts for their timeliness – due to their quick, intense nature, they’re great to squeeze in during a lunch break or before work. Train hard and fast for optimum results and we guarantee you’ll fall in love. The endorphins you feel after these techniques are next to none.

How do you promote muscle mass?

Put simply: more load = more gains. Promoting muscle growth is a delicate balance between diet, workout routine and appropriate recovery to avoid injury. Strike this balance, however, and you’ll be in the money.

 Muscle growth techniques

When it comes to exercise inspiration, there is a sea of information out there, so it’s important to find exercises that work for you and your specific fitness goals. The main thing to remember is that consistency is key; continue to challenge yourself and stick to your goals long-term. That’s when the best results will come!

Strength and resistance training

Strength and resistance are the key to building muscle mass. People regularly incorporate weights and resistance bands, which are elastic bands, often covered in fabric for the user's comfort, that are highly effective in training and promoting muscle growth. The bands were originally used for rehabilitation purposes until the effectiveness of this technique for muscle growth was noted.

Using weights

Depending on the specific muscles you are targeting, use of weights are the primary method to achieving muscle growth. Aside from this, free weights are a great, effective method in targeting growth. These are a really simple way to up your workout and increase your gains.

  • Arms: Dumbbell Curls

If you’re looking to increase the muscle growth in your arms, you want to target your triceps and biceps. These muscles are easily activated through the use of dumbbells – or if you’re working out from home, any item that provides weight. This could be a bottle of milk or maybe a brick, depending on your requirements and capabilities.

With a weight in each hand, stand with your feet shoulder-width apart with your arms down by your sides. Stand in front of a mirror if you can to ensure you are maintaining your form, and slowly curl the weights upwards towards your shoulders. Repeat to complete your set.

You can actually incorporate dumbbells into many of your favourite HIIT routines: burpees, push ups, mountain climbers – you name it. If you feel confident, add in some dumbbells and up the tempo to create a high intensity workout.

  • Legs: Weighted Squats

Leg day is a HIIT athletes’ favourite. Nothing compares to the burn you get after a good session. To target your lower body, we recommend you opt for squats and deadlifts. But for a HIIT workout, squats and pulse squats are your best friend.

Load the barbell with your desired weight or use the bar alone if you are just starting out – it’s usually around 20kg by itself! If you haven’t tried this before, try with a friend first and make sure you're happy with your form during a bodyweight squat before you continue any further.

Stand tall with your feet slightly wider than shoulder-width apart below the barbell. Make sure the space around you is clear to avoid any potential injuries, and get a good grip of your bar.

Bend your knees and hips simultaneously and lower yourself into the squatting position, and then return back to your standing, resting position. Keep your chin and chest up to maintain good form, helping to prevent injury. Repeat. We recommend three sets of twelve reps, but this entirely depends on your experience and capabilities as to how you implement these strength training exercises.

Top tip: add a resistance band around your thighs for some extra burn!

  • Abs: Medicine Ball Crunch

Get ready for some great strength training and the ab burn of your life. Sit on a flat, soft surface with your legs stretched out in front of you. Grab a medicine ball at a weight of your choice and lie down flat on your back with your arms stretched behind you.

In one, swift movement, bring your arms and feet together above you in the air. Hold it, and then slowly release, holding your core tight as you move. Repeat your reps and time your workout to the recommended Tabata protocol for a real HIIT burn. The aim of these workouts is to push your body to the limit with the intensity of your exercises. Here, you are trying to achieve MMF to maximise your muscle growth and results.

What is MMF?

Momentary Muscular Failure, or MMF, describes the state of your muscles following a high intensity and gruelling workout. This is the point that you reach when no more reps of your chosen exercise can be performed with perfect form due to the strain on your muscles.

Reaching MMF is an important step in continuing and maintaining muscle growth, as this state pushes your muscles to rip. Here, you are aiming to tire your muscles to create these tears, which speeds up your muscle gains (if adequate recovery is maintained).

Summary

HIIT workouts are a great time effective and goal-orientated fitness technique that can absolutely be incorporated to promote muscle growth. Whilst we’ve given you three examples, these definitely aren’t extensive – so if these aren’t for you, check out some more of our workout guides for inspiration. Pair these workouts and a healthy, balanced diet with The Power Booster and really reap the benefits and hit those fitness goals ASAP.

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The Best Supplements for Muscle Recovery
Nobody has ever asked me which supplements are best for muscle recovery. Instead, they ask how to build muscle. They ask how to tone up without getting bulky. Recovery is a big part of the answer to both, but one that nobody goes looking for. Which is a shame, because it's where an enormous amount of good training goes to waste. It's also where a lot of money gets wasted. Your local supplement shop or preferred online retailer is almost certainly full of products that either duplicate something you're already taking or do a completely different job to the one implied on the label. Neither makes them bad products, but it does make them a poor use of your budget. The short version is like the rest of the fitness industry – there’s a ton of misinformation out there and it’s easy to get lost in the noise. So this is the list I'd give you if you asked. Nine supplements that are well worth considering, three that are probably worth giving a miss, and how to put them together without paying twice for the same thing. Key takeaways Protein, creatine and tart cherry have the strongest evidence behind them. If you only ever buy three things, buy these. Magnesium, zinc and vitamin D don't speed recovery up so much as lessen the things that hold it back. Vitamin D is crucial, especially through a British winter where there’s not as much sun. Omega-3 and curcumin help manage the inflammatory response. These are useful during heavy training blocks, but not something you want to suppress all year round. Carbohydrate and electrolytes only become a priority when your recovery turnaround is short: think two sessions a day, endurance work, or training in heat. BCAAs aren't a recovery supplement. EAAs work but they usually duplicate your protein powder if it’s high quality. Glutamine's evidence in trained, well-fed people is weak. Tart cherry appears to help you produce force again sooner rather than make you feel less sore, which is the more useful of the two anyway. No supplement compensates for poor sleep, insufficient protein or badly managed training load. What recovery actually involves Before we get to the list, we should take a moment to understand what we're asking these supplements to do. It’ll also start to explain why some of them work and why others never really had a chance. After a hard session, you need three things to happen. Your muscles need repairing, which requires a steady supply of amino acids (the building blocks of new muscle tissue). The inflammation that follows training needs to run its course and resolve; it isn't the enemy here, it's part of how you adapt, but it does need managing rather than leaving to run wild. And your body needs to refuel and reset: your muscle glycogen needs replenishing, hydration restored, and your hormones and nervous system brought back to baseline, most of which happens whilst you're asleep. Which means a supplement can really only do one of three jobs. Supply raw materials. Moderate the inflammatory response. Or support the systems doing the actual repair work. If it doesn't fit into one of those three categories, it's an expensive maybe at best. Keep that in mind as we go, because it's the quickest way to work out whether something belongs in your stack. We've covered the science of post-workout recovery and what's actually happening when you get DOMS in more detail elsewhere. This piece is about what to take to aid things. The non-negotiables These three have the strongest evidence behind them and the biggest practical effect. If you only ever buy three things, make it these. Protein powder (the type matters less than you think) Protein is the raw material. It’s the headliner of recovery and anything muscle related as a whole. Everything else here is a supporting act. You can't build a house without bricks, and you can't rebuild muscle without amino acids. The research points fairly consistently to 1.6g to 2.2g of protein per kilogram of bodyweight per day if you're training seriously, spread across the day in servings of roughly 0.3g per kilogram. For most people that's 25g to 40g at a time. Powder isn't magic. It's simply the most convenient and cost-effective way to close the gap between what you eat and what you need. Where it gets interesting is which type, because that's where you hear a lot of marketing noise. Firstly, should you choose whey concentrate or isolate? Isolate is filtered further, so it comes in around 90% protein by weight against roughly 70-80% for concentrate, with less lactose and less fat. But here's the part the labels tend to skip: when your total daily protein is matched, isolate has no meaningful advantage for muscle growth or recovery. Choose it if lactose bothers you, or if you're on a tight calorie budget and want the nutrient density. Don't pay extra expecting more muscle. It pays (literally) to know what you’re getting. Casein digests more slowly and gives a sustained release of amino acids over several hours, which makes it quite useful before bed or across a long gap between meals. The better protein blends usually include at least some casein for exactly that reason. Egg protein is excellent, and one of the best options if you're avoiding dairy. But it's worth clearing up a myth that refuses to die: egg is not the most bioavailable protein you can buy. On DIAAS, the current gold standard for measuring protein quality, whey and milk protein score at or above whole egg. Egg is very good. It just isn't the winner it's usually sold as. You deserve a straight answer about beef protein too. It’s often marketed as a cleaner, lower calorie alternative to whey, but a significant proportion of beef protein products are made from hydrolysed collagen or gelatin rather than muscle meat, and collagen has a poor amino acid profile for our purposes. Very little leucine, and no tryptophan at all. It simply can't drive muscle protein synthesis the way whey does. The same applies to collagen powders generally: collagen is a protein, but it isn't a muscle-building one. For most people, a blend covering both fast and slow digesting sources is the most sensible choice. The Strong Protein gives you 34g per serving from whey concentrate, whey isolate and casein together, so you get the immediate spike and the sustained release without managing two tubs. Creatine monohydrate Creatine is the most researched supplement in sports nutrition, and it still gets filed under "strength and size" rather than recovery. That's a mistake. People view creatine purely for its ability to enhance performance, and it definitely does, but it also has value for recovery. That value lies in how quickly you can produce force again. By topping up the phosphocreatine system that fuels high-intensity effort, creatine helps restore performance between hard sessions, and it plays a role in glycogen resynthesis alongside carbohydrates. I do need to provide one honest caveat though. The evidence on whether creatine actually reduces markers of muscle damage is genuinely mixed. One systematic review is titled, without a hint of irony, The Paradoxical Effect of Creatine Monohydrate on Muscle Damage Markers. So I won't tell you it lowers your creatine kinase. What it reliably does is get you back to training hard sooner, which, being honest, is the outcome that really matters to many of the people taking it. Take 3-5g daily, every day, rest days included. Timing is irrelevant. Consistency isn't. You don't need to load, and you want plain monohydrate; the more expensive forms have never convincingly beaten it. If you want a proven, science-backed source of quality creatine, you can find that right here on the Innermost site. The Power Booster is 5g of German-sourced creatine monohydrate and nothing else. There's also 3g built into The Strong Protein if you'd rather not manage another tub. Tart cherry (montmorency) Most articles on the subject of tart cherry get it slightly wrong, so let’s be precise and clear things up. You'll usually see tart cherry described as a soreness remedy. A 2026 systematic review and meta-analysis of 19 trials found something more interesting. There were significant improvements in the recovery of maximal voluntary contraction (your ability to produce force), and the effect grew over the days following exercise. There were also reductions in C-reactive protein, a marker of inflammation. What there wasn't was a significant pooled effect on muscle soreness itself. So tart cherry appears to help you perform again sooner rather than help you feel less sore. If you're training or competing to a schedule, that's comfortably the more useful of the two. The authors of the review do flag low to moderate certainty and a lot of variation between studies, so treat it as promising evidence rather than set in stone fact. There's one other thing worth adding. Inflammation is part of the signal that drives adaptation, so suppressing it aggressively all year round may cost you some of the progress you're training for. Use tart cherry when recovering quickly genuinely matters more than adapting maximally. That might be during competition weeks, a congested fixture list, or perhaps a hard training camp. Then take it back out. The Strong Protein includes 300mg of Montmorency cherry alongside 250mg of bilberry, both for their anthocyanin content. The supporting cast These four won't transform your recovery on their own. What they do instead is help to lessen the things that might be holding it back, which for a lot of people is where the real gains are hiding. Magnesium Magnesium is involved in hundreds of enzymatic reactions, including muscle contraction and relaxation, energy production and protein synthesis. It's also one of the more reliable influencers of sleep quality, which makes it a recovery supplement twice over. It's worth paying attention to because UK intakes are frequently below the recommended daily amount, particularly among younger adults, and hard training increases what you lose through sweat. Form matters more than dose here. Magnesium glycinate or citrate are far better absorbed than the cheap magnesium oxide you'll find in most supermarket products. Aim for 200-400mg daily. There's 200mg in The Strong Protein, and magnesium appears again as part of the ZMA in The Recover Capsules. Zinc Zinc supports immune function, protein synthesis and hormone production, and like magnesium you lose it through sweat, so heavy training weeks are sure to increase the amount you need. We need to be precise about the hormonal claim here, because this is one of the most oversold supplements going. Zinc supports normal testosterone production if you're deficient. It will not push your levels above normal if you're already topped up, and no amount of fancy packaging will ever change that. Correcting a genuine shortfall is worth doing. Chasing a hormonal edge you don't have isn't. Don't megadose either, because sustained high zinc intakes interfere with copper absorption. Around 10-15mg a day is plenty for most people. The Recover Capsules include zinc as part of their ZMA content if you’re looking for a supplement to cover multiple bases in one. Vitamin D If you train in the UK, Vitamin D is one of the things that’s likely to be limiting you without you even realising it. Between roughly October and March, the sun doesn't climb high enough at our latitude for your skin to make meaningful amounts of vitamin D, no matter how much time you spend outside. The NHS advice is that everyone should consider a daily supplement through autumn and winter for exactly that reason. For recovery specifically, vitamin D is involved in muscle function and force production, and low levels have been linked to reduced strength and higher injury risk in athletes. It's also the least exciting item on this list, which is probably why it gets skipped over. Our Recover Capsules provide 1000IU per serving, which is 500% NRV. Whether you choose them or not, make sure you’re getting enough Vitamin D! I truly can’t stress that enough. Omega-3 (EPA and DHA) Omega-3 fatty acids help resolve your body’s inflammatory response rather than simply blunting it, and there's reasonable evidence for reduced soreness and better retention of muscle function after damaging exercise. Look for around 2g of combined EPA and DHA daily, and read the label properly. Plenty of fish oil products advertise an impressive capsule size whilst delivering a fraction of that in actual EPA and DHA. Third-party testing for purity is worth paying for if you’re unsure, and algal oil is an equivalent option if you don't eat fish. Worth it in specific situations These two aren't for everyone. In the right context, though, they're excellent. Curcumin Curcumin, the active compound in turmeric, has built up a reasonable body of meta-analytic evidence for reduced muscle soreness, lower creatine kinase and better retention of functional strength after damaging exercise. It's doing the same job as tart cherry: managing the inflammatory response rather than supplying raw materials. Bioavailability is the main thing to consider here. Curcumin on its own is poorly absorbed, so adding more turmeric to your cooking won't achieve anything useful. Look for a formulation enhanced with piperine (a natural compound found in black pepper), or a phytosome or liposomal preparation. Apply the same caveat as tart cherry. This is a tool for congested periods, not a year-round default. Carbohydrate and electrolytes Refuelling is the third job, and it's the one most lifters can happily ignore. If you train once a day and eat properly, your normal meals will restore glycogen comfortably before your next session. It becomes a real priority when the turnaround is short. If you’re doing two sessions in a day, lots of endurance work, compete in tournament formats, or are training in heat, you might need some additional support. In those cases the research points to roughly 1.0-1.2g of carbohydrate per kilogram of bodyweight per hour in the first few hours after finishing, which is difficult to hit through solid food alone. Hydration belongs here too. Sweat costs you fluid and sodium, and turning up to your next session dehydrated will take more from you than most supplements can give back. The Hydrate Blend covers the electrolyte side with sodium, potassium, magnesium and calcium. It’s well worth considering if you’re in the market for a top tier electrolyte blend. What about BCAAs, EAAs and glutamine? This is where a lot of people spend too much money, so let's be direct. BCAAs Branched-chain amino acids aren't a recovery supplement, and the reason is simple. They're three of the nine essential amino acids, and you can't build a complete muscle protein from an incomplete set. If your daily protein is adequate, adding BCAAs on top adds nothing to the repair process. That's a separate question from whether they do anything at all. Taken before or during training they have a role in perceived exertion and central fatigue, helping the session feel more manageable rather than helping you recover from it afterwards. That's a legitimate job, and it's why you'll find 5g of BCAAs in The Workout Blend, sitting alongside citrulline, beta-alanine and caffeine in a pre-workout formula. Just don't buy them expecting a recovery benefit they were never designed to deliver. EAAs Essential amino acids do work. All nine are present, so unlike BCAAs they can genuinely fuel muscle protein synthesis. The problem is redundancy. If you're already hitting 1.6-2.2g/kg of protein a day from food and a protein powder, you're paying a second time for something you've already bought. There are real cases where they earn their place. Poor appetite. Avoiding dairy without a good alternative. Training fasted first thing in the morning. Older trainees dealing with anabolic resistance, where the leucine threshold is genuinely harder to reach. Outside of those, sort your total protein out first and pay close attention to your diet overall. L-Glutamine Glutamine has a strong reputation and a weak evidence base, at least for the people usually buying it. In trained, well-fed individuals it has repeatedly failed to produce meaningful improvements in soreness, strength recovery or body composition. The gut and immune benefits people cite are real enough, but they come largely from research in extreme endurance loads and clinical settings. Those are states of physiological stress that lifting three to five times a week simply doesn't replicate. If you're training hard and eating enough protein, you're almost certainly getting plenty of glutamine already. You’d be better off spending that money on protein or creatine. How to build your recovery stack Rather than buying everything at once, build it in layers. The Foundation: protein, creatine, vitamin D. This is the version almost nobody regrets. Raw materials, force restoration, and the deficiency most likely to be holding you back. If budget is tight, stop here. You're already in a really strong position and are capturing the majority of the benefits available from supplements when it comes to muscle recovery specifically. Complete: add magnesium, zinc and omega-3. Worth it once you're training four or more times a week and the basics are consistent. These address what accumulates with volume, and the sleep quality everything else depends on. Hard block: add tart cherry, curcumin, carbohydrate and electrolytes. Reserve these for periods where recovering fast genuinely matters more than adapting maximally. Then take them back out, save your money and rely on your diet, which should always be the foundation of everything you put into your body anyway. Notice that the list gets shorter as your budget gets tighter, not longer. That's deliberate. The most important recovery tool isn't a supplement It would be strange to write all of this without saying the obvious thing. Sleep is the single biggest recovery variable you have, and no combination of capsules compensates for consistently getting six hours or more of sleep a night. Your total daily protein matters far more than which powder you choose. And managing your training load, programming deloads before you need them rather than after, will do more for how you feel and perform than anything on this list. Supplements are worth taking. They're worth taking because they close specific, identifiable gaps, not because they replace the fundamentals. They're the final few percent, and the foundations have to be there first. If sleep is where you're struggling, The Reset Capsules combine reishi, L-glycine, lemon balm and chamomile for exactly that. But the habits come first. Read more
Your Summer Survival Kit (From Someone Who Travels A Lot)
I'm putting the finishing touches to this post from an airport, which feels appropriate. By my count, I'll be going through three countries in the next six weeks. Meetings, a trip to see family including my niece and nephew, a supplier visit in Italy that I've been putting off for a year. And every summer the same thing happens. The carefully built routine, the one that took months to lock in, gets thrown into a suitcase and I hope for the best. Most people react to this by either giving up on the routine entirely ("I'll sort it out when I'm back") or overpacking so aggressively that half of it never leaves the bag. I've done both. Neither works. What actually works is deciding, in advance, which two or three things earn a place in my bag and which ones can wait until September. So here's mine. Not a wellness influencer's "what's in my bag" video. An honest list, built over about a decade of getting this wrong first. Why travel breaks routines specifically It's worth being precise about what actually changes when you travel, because it isn't just "less discipline." Three things shift at once. You sweat more and drink less water than usual, because you're distracted or the flight dried you out or the hotel room is warmer than home. You're outdoors more, often somewhere sunnier than wherever you live. And your meals stop being yours. You eat what's available, when it's available, and protein is usually the first thing to slip, because sugar, carbs and fat are what's on offer at 6am airport cafes. None of this is a discipline problem. It's an environment problem. The fix is making sure two or three specific things are in my bag before I leave home, so I’m not relying on willpower to begin with. 1. Electrolytes, non-negotiable Most people remember to pack sunscreen. Almost nobody packs electrolytes, and it's the one that actually catches up with you. Water replaces volume, not what you lose through sweat, which is mostly sodium and potassium and magnesium doing the quiet work of keeping muscles firing and fluid balanced properly. Miss that balance for a few days in the heat and you get the symptoms everyone blames on jet lag: the headache, the flat energy, the slight fog by 4pm that a coffee doesn't fix. It's usually not jet lag. It's electrolytes. I take The Hydrate Blend  for exactly this reason. Six electrolytes, no sugar, no synthetic flavouring, dissolves in a bottle of water in about ten seconds. One sachet on a travel day, first thing in the morning, does more for how I feel by evening than anything else in the bag. 2. Something for the sun you're actually going to get Here's the part most people don't think about until it's too late. UV exposure accelerates collagen breakdown, which is a slightly clinical way of saying that a week of proper sun does more to skin structure than most of the year combined. This isn't about vanity. It's a straightforward mechanism: UV generates free radicals that degrade existing collagen faster than your body can replace it. Sunscreen protects against the burn. It doesn't do anything for the collagen you're losing underneath. I've been taking The Glow Blend through summer for this reason specifically. Hydrolysed collagen peptides paired with vitamin C, which matters because vitamin C is a required co-factor for collagen synthesis and most collagen products leave it out entirely, then wonder why customers don't notice anything. It won't undo a week in the sun. It gives your skin something to rebuild with while it's under more pressure than usual. 3. Protein, especially when the meals aren't yours This is the one I've learned the hard way. When your diet goes inconsistent, protein is usually the first macronutrient to drop, simply because it's the hardest to find on the move. Airport food, hotel breakfasts, whatever's left at a conference buffet by 1pm, none of it is built around protein. And the honest science here is less dramatic than people expect: you don't need to train harder to maintain muscle through a disrupted period, you need to keep protein intake somewhere close to normal. That's the whole trick. I'll say this honestly because I'd rather be straight with you than pretend otherwise: my go-to for this is still The Strong Protein (whey based) and The Health Protein (vegan). They earn their place in my bag because they travel well, mix with nothing but water, and does the one job that actually matters on the road, which is making sure protein doesn't disappear from your day just because your routine has. The actual point None of this is about maintaining perfect discipline on holiday. Nobody does that, and if a brand tells you they do, they're not being honest with you. It's about deciding in advance which three or four things matter enough to bring, so the choice isn't being made for you by whatever's in the hotel minibar. If you've got a system that works for you when you travel, reply and tell me. I read every one of these, and I'm always looking to steal a better idea for my next trip. If this is useful, forward it to whoever in your life is about to live out of a suitcase for the next few weeks. It's the email I wish someone had sent me a decade ago. Read more