Free delivery on orders over $99. Simply use discount code "FREE" at checkout. Terms & Conditions apply.
0 Cart
Added to Cart
    You have items in your cart
    You have 1 item in your cart
    Check Out Continue Shopping
    So what does your body actually need during endurance exercise?

    No matter what kind of activity you’re doing, whenever you're exercising hard for several hours at a time your body loses water and sodium in sweat. It also burns calories, mostly in the form of carbohydrates stored in your muscles and liver.

    Water, salt and calories are therefore essentially the main ‘costs’ of doing an endurance event.

    The nuts and bolts of any sensible nutrition plan should therefore be largely based on replacing varying proportions of each of these three items to enable you to sustain your performance.

    When it comes to fuelling, I find it helpful to break activities down into three broad categories...

    1. ‘Short’ activities (less than about 90 minutes)
    2. ‘Medium to Long’ activities (about 90 minutes to 4 hours)
    3. ‘Ultra’ activities (4 hours+)

    Short activities (less than about 90 minutes)

    Before you start

    Make sure you begin whatever you’re doing topped up with fluids, electrolytes and carbohydrates. Trying to make up for a deficit if you start a bit dehydrated or energy depleted by eating and drinking during the activity itself is definitely leaving it too late. 

    From a hydration perspective this is relatively simple. Drink 500ml (16oz) of PH 1500 the night before your event and another 500ml about 90 minutes before you start, aiming to finish your drink no less than 45 minutes before go-time.

    Remember, one of the main benefits of preloading before shorter activities is that it should reduce (or even remove) the need to drink much during your activity...

    Whilst you're sweating

    If you start most shorter activities well fuelled and properly hydrated, there's usually little to be gained from taking in large amounts of anything - be that water, electrolytes or calories - during the activity itself.

    Your body has what it needs to last this long in reserve (even at a relatively high intensity) and you can simply refuel and rehydrate afterwards to replenish stores for next time.

    This doesn’t mean you categorically shouldn’t consume anything during exercise lasting less than 90 min. You should absolutely still listen to your body and eat or drink if you feel you really need to (and it's also a bright idea to eat and drink something if you're training again very soon afterwards so you don't start the next bout of activity really depleted), but it’s worth understanding that the impact that nutritional intake is going to have on your performance during the race or session itself is probably quite negligible.

    A slight exception to this rule might be if you are competing at the elite end of the spectrum in very high intensity aerobic events. There is some evidence that ingesting small amounts of a carb based drink (or even just rinsing it your mouth) can be beneficial to your performance in those circumstances.

    Essentially the ‘mouth rinse effect’ is thought to be because receptors in the mouth shout to the brain ‘SUGAR IS COMING!’ (even if you just spit the drink out) and your brain then allows your body to work harder than it otherwise would - presuming more energy is on the way - tricking you into putting out a stronger performance than might otherwise be possible.


    Sugar and strawberries
    Image by Mali Maedar via Pexels (copyright free)

    This (along with keeping topped up for subsequent sessions or events) is one of the reasons why we still sometimes recommend having a bottle of the all-natural Precision Fuel and Hydration drinks to sip at during shorter events when this is convenient.

    Medium to Long activities (about 90 minutes to 4 hours)

    The academic consensus

    It’s during medium to long sessions that fluid intake and carbohydrate fuelling in particular starts to have more of an impact on performance.

    There's a whole heap of research out there on the effects of carbohydrate ingestion on performance during longer periods of aerobic exercise. A 2013 paper called The use of carbohydrates during exercise as an ergogenic aid' gives a decent overview if you want to dig into some of the technical details without doing your own PhD on the subject!

    The bottom line from all that research and the current consensus is that taking in around 60g of carbohydrate per hour is optimal for most endurance athletes doing 2 to 4 hour activities. Think more like 40g/hr if you’re a smaller person and not working at a high intensity, but maybe as high as 90g/hr if you're bigger and going really hard at it. This carbohydrate can come from a range of sources including drinks, bars, gels and ‘real’ foods (if their composition allows for easy consumption and digestion).

    Before you start

    Again, it's important to make sure you begin whatever you’re doing well hydrated and fuelled. Trying to make up for a deficit is definitely leaving it too late.

    • Drink 500ml of PH 1500 the night before your event.
    • Drink 500ml of PH 1500 around 90 minutes before you start (finishing ~45 minutes before you begin)
    • Don’t just drink lots of water or 'low strength electrolytes' in the build-up to an event. You can end up diluting your body’s sodium levels before you start sweating.

    Whilst you're sweating

    About 90 minutes to two hours is usually the threshold at which sweat losses can become significant, so fluid needs must be considered along with fuelling at this point too.  

    If you’re using the all-natural range as your primary source of fluids, the important thing you need to know is that they contain around 17g of carbs per 500ml (16oz) bottleThis makes the drinks hypotonic (i.e. a lower concentration than your blood), so they’re easily absorbed by the gut. But, unlike isotonic drinks, they don’t deliver all of the carbs you’re likely to need during your activity. 

    It’s also crucial to remember that the effervescent tablets and SweatSalt capsules contain close to zero calories, so these won’t contribute to your energy intake at all. 

    Some example scenarios

    If you drink about 500ml (16oz) per hour in cooler conditions, on average you'll be getting 17g/hr of carbs from your all-natural PH drink, so will need to take in around 43 grams of carb/hr from somewhere else.

    Most energy gels contain about 20-25 of carbs per pack, so 2 of those along with the PH drink ought to work fine. Some energy bars contain as much as 35-40g per serving, so one of those alone will also come close as an alternative.

    If you prefer your carbs a bit more 'old school', then 8 Bassetts Jelly Babies contains 42g, so this could do the trick. Or, if you want to go 100% natural you could go for about 1.5 bananas, as they tend to contain around 25-30g of carbs per fruit. Though what you’d do with the leftover half, I’m not exactly sure...


    Image by Charles Deluvio via Unsplash (copyright free)

    In hotter conditions, where your fluid intake is likely to go up towards 1 litre per hour (32oz/hr) then you’ll now be getting up to 34g of carbs from your PH drinks, so you'll be able to reduce the amount you eat accordingly. This would mean just taking in around 1 energy gel, half an energy bar, 4 jelly babies or 1 banana.

    We do know a few athletes who have very high sweat rates and can also absorb as much as 1.5 litres per hour of PH drink when they're racing or training, usually in very hot conditions. These guys are already getting 51g of carbs from their drinks alone, so only need a relatively small amount from other sources to meet their fuelling needs.

    These examples highlight that your fuelling and hydration intake need to be tweaked in proportion to one another based on sweat loss and fluid absorption.

    Bear in mind that if you don’t decrease your calorie intake from solid or semi solid foods at times when fluid intake is very high it can be a recipe for GI distress and this is a major reason why traditional isotonic sports drinks (i.e. those with a lot of carbs in, making them a similar concentration to your blood) can be very difficult to live with in longer and hotter events. That's because your need for fluid starts to be proportionally greater than they can comfortably deliver via your water bottle without overdosing you on sugar. 

    These kind of events are also not quite long enough for you to get really sick of sweeter products and flavours, so it’s usually possible to get to the end without suffering the kind of nausea that so often occurs when you rely too heavily on sugar as you main source of calories during longer events.

     'Ultra' activities (4 hours+)

    Before you start

    As with shorter activities it's crucial to make sure you begin an ultra distance event or session well hydrated and fuelled. In fact, as you'll be out there for a lot longer, some would argue its even more important. Making sure you get it right before you start is what you'd call 'free money' in the ultra-distance game!

    We make a big deal about preloading with higher strength sodium drinks before these events. 

    • Drink 500ml of PH 1500 the night before the event
    • Drink 500ml of PH 1500 around 90 minutes before you start (finishing ~45 minutes before you begin)
    • DON’T just drink lots of water in the build-up to an event. You can end up diluting your body’s sodium levels before you start, increasing the risk of hyponatremia.

    Whilst you're sweating

    The required rate of fluid and carbohydrate ingestion for ultras is not dramatically different to what you should be aiming for during medium/long events. You’re still limited by the absorption rates in the gut for carbs and fluids, so the ~60g/hr and ~1l/hour maximums still apply. But, there are some notable differences to how we’d generally advise approaching fuelling for longer events.

    First - because you're going to be out there for much longer, there's a lot to be said for introducing more variety into your energy and fluid intake so that you don’t become sick of the taste of any one thing.

    Second - because you'll be going at a lower intensity than you would for shorter events, chewing and digesting more ‘real’ solid foods becomes a lot easier. This opens up a much wider range of possibilities for your race day menu. It also tends to keep your stomach a lot happier than asking it to process nothing but syrupy, sugary goo for hours on end.

    Third - sodium intake (along with appropriate amounts of fluid) becomes far more important during ultra distance events because the risk of hyponatremia increases along with total sweat losses. So, its more important than ever to be getting an appropriate level of electrolytes in with your drinks. Of course this is not likely to be a problem if you’re using the right strength PH drink for you, or if you're supplementing fluid intake with the right amount of SweatSalt capsules, but it's definitely worth make sure you have a solid understanding of this. 

    If you want to learn more about this, head on over to Precision Fuel and Hydration.