Weight loss for cyclists: a month of personal observations

In July I tried to lose some weight. Not because I was hugely overweight (although we’d all like to be a little lighter, wouldn’t we?) but because I was interested to see what was involved and how hard it would be.

When July 1 rolled around I didn’t have a specific weight target in mind. I started the month at roughly 82kg and my first goal was to get below 80kg. More importantly, the plan was to see what impact a month of disciplined eating and exercising would have and whether losing weight would be as easy as I thought it would be.

Why easy? Well, for the most part, losing weight is actually a pretty simple equation — burn more energy than you consume and you’ll lose weight. Sure, to have a healthy diet you also need to ensure you’re getting all your daily nutritional requirements — but assuming you’re doing that, losing weight is just about consistently creating an energy deficit.

If we’re talking about energy deficits there are two factors at play: how much food you eat and how much exercise you do. It’s possible to lose weight by adjusting just one of these factors (eating less or exercising more) but, ideally, you should be doing both.

From July 1 I started keeping a close eye on my energy input and expenditure. I downloaded the EasyDietDiary iPhone app and used it religiously to track exactly what I was eating, breaking every meal and every snack down into its component parts. It was a tiring process at times, but I’m a bit of a stats junkie so mostly I just found it fascinating. At the same time I also ensured I always wore a heartrate monitor while exercising, to track how much energy I was burning.

Doing these two things together gave me a fascinating perspective on my daily energy input and output that I simply didn’t have before. The 4,000kJ burned during a 40km ride, for example, wasn’t simply a number in a Strava activity page any more; it was now the equivalent of a big dinner of homemade chicken parmagiana with mashed potato, veges, and a glass of orange juice. Or the equivalent of roughly 10 Tim Tams or 13 red apples or eight slices of white toast with peanut butter.

Every day I would keep track of how much energy I was “owed”. I’d add the energy expenditure of any exercise I’d done that day to an estimate of my daily, sedentary energy requirements; a number I estimated at 9,000kJ based on National Health and Medical Research Council guidelines.

On day 5, for example, I had a late breakfast (~3,500kJ of muesli with milk) then headed out on a ride in which I burned 6,800kJ and ate one energy bar (815kJ). Having had roughly 2,000kJ for lunch, I went into dinner with a buffer of nearly 10,000kJ. That is, I would have had to eat more than 10,000kJ to not have had an energy deficit that day.

Those days were my favourite; knowing that I was contributing to my weight loss, while still being able to eat as much as I wanted for dinner and dessert. But there were downsides to those days as well.

On day 10 I ate a total of 4,600kJ for breakfast and lunch before heading out for a ride that burned roughly 6,300kJ. So when I got home from my ride, and with dinner time approaching, I was again “owed” more than 10,000kJ. But I felt rubbish. I had no energy at all, I was lethargic and my blood sugar levels were obviously very low. The best way I can describe it is to say that it felt like I was “bonking”, albeit while sitting on the couch rather than while out for a ride.

I had a similar situation on day 4 when I thought I’d try a pre-breakfast ride which, reportedly, helps you burn fat (rather than the carbohydrate you’ve just poured in for breakfast). I went into the ride hungry and got progressively hungrier as the ride went on. I kept telling myself “this is doing you good, push through!” but I ended up feeling nauseous and lethargic for the rest of the day.

I found myself swinging in the other direction at times too, getting lulled into a false sense of security and eating too much. On day 17, for example, I spent 45 minutes on the stationary trainer, burning 2,400kJ in the process. When I got back inside I figured “I’ve just burnt all this energy, I deserve some dessert”. So I helped myself to a slab of chocolate pudding which, I found out later, was about 3,000kJ worth. Forty-five minutes of hard work undone in five.


Going into this process I wasn’t quite sure how much weight I’d be able to lose. Like everyone I’ve seen those ads for exercise equipment and diet products where the folks in the ads lose 1kg a week or more, but I didn’t know if that was realistic. I was weighing myself daily which made it hard to see any noticeable gains from day to day.

Often there’d be no change at all and on a couple of occasions I even managed to be heavier than the day before. On day 8, I wrote in my weight loss diary “Gone backwards slightly, but not sure how! Been counting calories religiously!” Those days were frustrating, particularly when I’d had a smaller dinner than normal, or skipped dessert the day before for apparently no gain.

In the end I lost somewhere in the vicinity of 3kg in the month, taking me from 81.4kg down to 78.4kg by the end (+- 500g for daily fluctuations). While I was glad to have shed those few kilos, I was more interested in the process, what it had been like and what I could take from it going forward.

I learned that trying to lose weight means getting well acquainted with the feeling of being hungry, including going to bed hungry. I learned that weighing yourself everyday can be demoralising — weight loss is about an extended period of watching what you eat, it’s not simply a day-by-day prospect.

But probably the biggest thing I learned was that keeping track of what you’re eating really does make you more disciplined. When you’re not watching your weight it’s so easy to just head to the pantry for a snack in the evenings, not thinking anything of it. But if you have to add each biscuit or piece of chocolate to a record of your daily energy intake, it starts to make you question whether you really needed that snack in the first place.

I’ve taken that fresh perspective with me and I feel it will change the way I think about eating from now on (in a good way). I’m keen to try another sustained period of attempted weight loss, next time in preparation for a hilly cycling event where a few less kilos to drag uphill will be a great benefit.

Part of the problem for me in July was that I didn’t actually do that much exercise — probably less than I normally would. For a start it was the middle of winter (cold, wet and miserable) then there was the fact I was working strange hours, reporting on the Tour de France. Going to bed at 3am (at the earliest) and getting up late morning made it hard to find time to get out for a ride. I wouldn’t be surprised if my disrupted sleeping patterns had an effect on my metabolism as well.

In all I found it to be a fascinating personal experiment and one that I’m glad I did. I certainly don’t claim to be an expert in this area, but next time I try to lose weight I’ll certainly have some experience to draw on to improve the process. In the meantime though, here are a few things I learned that might help you if you’re trying to shed a few kilos:

  • Set yourself a target. Losing weight is challenging and it takes a lot of motivation and discipline. Be honest with yourself about why you’re doing this and what you want to get out of it. Having a clear target will help you stay motivated far more than a simple goal of “I want to lose weight.”
  • Eat less and exercise more. Doing one or the other is fine, but if you want to see real results you need to be doing both.
  • Keep track of how much energy you’re taking in and putting out. Quantifying your daily energy input and expenditure will give you an objective measure of how the process is going. Your goal should be to reach an energy deficit each day.
  • Be patient and disciplined. Weight loss doesn’t happen overnight. If you go into it expecting to lose huge slabs of weight straight away you’ll likely be disappointed. Focus more on staying disciplined and remember it’s the long game that’s important. Consider weighing yourself once a week rather than every day.
  • Be prepared for setbacks. There might be days or weeks where you don’t lose weight. You might even put a little bit back on. Don’t let this get you down. Focus on your target, stay disciplined and work towards your end goal, rather than getting yourself down.
  • Be sensible and stay healthy. Don’t be silly about losing weight — it’s a long, slow, gradual process that shouldn’t be rushed. Heading out on a 100km ride before breakfast with no food is likely to do you more harm than good. Also ensure your diet is balanced and well rounded. Just because weight loss is largely about energy in vs energy out, doesn’t mean you shouldn’t be getting all your essential nutrients.

Have you tried to lose weight through cycling? How did you find the process? Is there anything you’d add to the tips above?

Feature image by Flickr user Alan Cleaver.

36 Replies to “Weight loss for cyclists: a month of personal observations”

  1. A climb of 500m long with 20m elevation gain and 3.7% gradient.

    I am an experienced cyclist weighing 90kg on a 40 year old steel bike. I can do 19kph according to Strava. Others are posting 40-50kph and higher…….. are they lying??

  2. “Eat less and exercise more. Doing one or the other is fine, but if you want to see real results you need to be doing both.”

    I agree with your article, except for the above. Exercise is not necessary to lose weight. Putting back less energy than you expend is necessary to lose weight.

    Exercise induces hunger. The body will want to put back in what it lost in energy. You still have to eat less than you’ve expended in energy.

    Exercise has many benefits. Losing weight isn’t one of them.

  3. I’m new to cycling but have found it a great way to lose weight. At 59 that is a real challenge. My approach was different to yours as I don’t have the patience to calorie count, so I made some easy to follow rules.

    1. Always have breakfast, usually muesli and yoghurt.
    2. Don’t buy any biscuits, sweets, soft drinks or snacks, so bye bye peanuts and crisps while watching tv
    3.You will get hungry at times, so always have fresh fruit handy.
    4.Use a smaller dinner plate and never go back for seconds.
    5. Make that fish and chips, fish and errrr fish….
    6.Have a good nutritious meal before 8 in the evening and do not eat after that. So as you said, be prepared to want to eat, and have self discipline to go to bed hungry. It’s worth it.
    7. Treat yourself to a road bike, for me it was the Giant, Liv which was great specs for the price.
    7. Of course, increase exercise, which for me was my newly found addiction to cycling. Went from rides around 10k, to start, to over 50k. Always included hills, which is not difficult in the french pyrenees…. Now doing between 70-120kms a week which is not so great for proper cyclists, but feels like a real achievement for me, and I absolutely love whizzing down after a long hard climb.

    I went from 70kg, size 14 to 60kg size 10 in 6mths and have no intention of becoming a porker again…

  4. When a mate of mine set me the challenge of the 3 peaks 2015 I jumped at the challenge. I knew that there would be 2 aspects to this event (i) training, well that takes care of itself but the most important was (ii)losing weight 97kgs is way to heavy and carying this up those hills would not be funny. So hitting the scales in early March at 97kgs I am now 86kgs. I did seek some professional to help me out. I found that I wasn’t eating enough of the “good” food and I knew that my 8-9 cups of coffee/sugar would have to go. I went cold turkey and good a decent headache as a result but the effort was well worth it. I would love to ride the peaks at 82/83kgs and as winter is now behind me and I can spend more time on the bike I should be able to get down to my goal weight.

  5. I find that a good dose of gastro or the flu works wonders in losing weight quickly 🙂 I had the flu recently and went from 71 to 66kg, easy-peasy

  6. Awesome article, and great timing as we’re (hopefully) coming out of winter… It seems that I’m not the only one who struggles with the combination of wet / cold weather impacting both riding frequency and the temptation to sit on the couch with a ton (literally) of comfort food…

    Suspect there may have been a spike in downloads for the “EasyDietDiary” app today – I know I contributed as soon as I saw this article, and a whole 8 hours or so later its already made an impact.

    Someone way smarter than me once said something along the lines of “Just by measuring something, you change behaviour”, and its true. The mere act of knowing that I’m going to write down everything I eat has meant I’ve had my first chocolate / lolly / potato chip free day in months…

    Small victory, but its a decent good start as far as I’m concerned…

    Now if you could just post an article on an app that I can download to instantly give me Cancellara’s legs, I’ll be all set…

  7. At 46.5 years old I finally, with the help of MyFitnessPal realised just how many calories I was eating.

    Now, with that little app and some discipline, I have dropped nearly 7 kgs in 100 days.

    Another 7 to go.

    Some days are harder than others, but slow and steady wins the race.

  8. Great article Matt (and congrats for actually keeping disciplined on the food diary front – the hardest part!).

    I’ve just come off the back of a block of 8 weeks run training for the City2Surf and dropped 3kgs in the process.

    What has been most interesting is that my food intake over that period didn’t change dramatically (less beer, but not massively so) and my actual volume of exercise was been lower (shorter sessions and less hours of exercise). However the intensity of those sessions was ramped up considerably, as I was doing lots of interval training and high paced tempo running.

    Net effect was simply burning more kilojoules and faster (according to Strava) as my average heart rate during those sessions was right up near threshold.

    For example in one 45 minute, hard interval session alone I was burning up to 4,500 kilojoules (and in the City2Surf I managed to use up over 6000 kj!) which is equivalent to a 5 hour+ easy ride.

    What does all this mean for cycling weight loss? Intensity must matter. In hard, high heart rate hill climb sessions I’m burning through loads more kj in an hour than in 3 easy ones, which means ultimately I’m getting better results faster.

    It’s no means definitive, but it works for me!

  9. Exercising on an empty stomach continuously will train the body to use fat rather than carbs as its energy source. Also cutting out sugar and processed foods and replacing them with good fats will all help. The idea being the body has a limited supply of carbs but a near enough endless supply of fat. So if we can teach the body to fuel on far we should in theory have an endless reservoir of energy to call upon, which of course means we can go harder for longer!

  10. Edison, I too am one who finds it hard to lose more weight now for performance. In the last 8 weeks I’ve been keeping a very close eye on all body measurements, rather than just weight loss, so u get an idea of what everything is doing. The biggest factor for me now is body fat percentage, as just losing weight can lead to wasting away too much. Eventually the kgs come off, but it’s just a slow process. I find that it fluctuates way too much now too depending on what I eat. One day I can be 85kgs, the next 87kgs. It’s weird. So now all I do is make sure I give myself the energy I require to get thru my exercise and don’t worry about the scales too much. There’s no point in trying if u can’t get thru the day!! Don’t forget plenty of water either… Oh yeah, check out a book called ‘racing weight’ by Matt Fitzgerald, good insights into weight for peak performance

  11. Hi Matt,
    First of all great job on the weight u did lose, it’s not easy. I’ve been through a few weight loss regimes myself. I used to weigh 115kgs at 192cms, I got to 86kgs in roughly 9 months, then managed to drift back out to around 97kgs. I’m now back to 86kgs again and have managed to keep it there since march this year. I’ve found the 2 most important things are staying away from alcohol, especially beer, and incorporating strength training into your routine. Muscle development boosts metabolism and keeps the body using the calories u give it. I found that cycling alone didn’t help too much with weight loss, as it was too easy to bonk if u weren’t careful with energy requirements. After a while I’ve developed a routine where I’m super strict with what I eat during the week, and I relax a bit when the weekend comes, the includes being allowed to have a glass of wine or 2 on the weekend. I also work a physically labourous job outside, so I’m not sitting at a desk all day, which makes it much easier to get calorie burn! My go to foods are baked or steamed chicken breasts, steamed veggies, cottage cheese, fruit in the mornings and not too much bread. Be sure to get enough protein so u help muscle recovery, especially when you’re sleeping! And don’t forget the importance of a good breakfast, gets the metabolism kick started for the day!!

  12. I agree with Nick. It’s more complex than Energy In v. Out. In 2012 I lost 104kg (and then another 10 or so in the months after). Started riding an old mountain bike around the streets in the back half of 2012. Couldn’t reach the bars so put BMX bars on it. Food diary was the kickstart and being aware of what was going in was a big part of my weight loss. I lose weight easier when I am strict with diet rather than training. This year I gained 10kgs in 6months training for Cairns Ironman. The harder I work the hungrier I get. Anyway I’m going to do 3 peaks so I’m back on the regime. Good fun this bike riding stuff.

  13. Interesting article Matt, I’m interested in cyclists out there who have already reached a low weight and are still aiming to get lower by 1-2kgs without compromising performance output, from my own experience I cant seem to lower my weight any further without 1)training more which leads to degradation in the quality of the output (TSS, IF etc) or 2) lowering calories which leads to degradation in the quality of the output.

  14. Great article. I have lost over 40 kg in the last 10 years and managed to keep it off. Your observations and suggestions are spot on. Here my two cents worth …

    The small weigh fluctuations are mostly due to body’s hydration level as well and the frequency of bowel movement.

    The weigh loss science says for every kg of fat equates to just about 7000 calories. So you’d think a 1 kg weigh loss equates to 7000 calorie deficit. Not quite. Muscle and body tissues take less calories and seem to take priority in weight loss. So there come the exercise for a healthy weight loss that allows you to keep your muscles .

    Unfortunately, the weigh rate doesn’t stay constant. After a while the body adapts to calorie deficit (presumably due a metabolic slowdown) so your weight loss plateaus. The dilemma is that if you go back to your previous calorie intake levels, you will gain weight! 🙁

    Simply put body always tries to establish a balance. Changing this balance by varying your diet or activity level will affect your weight ONLY in the short term. That is why some overweight people remain at the same weigh levels despite continuously overeating. The same is also true.

    Anyhow, just some tips for tools to use for calorie counting etc.:

    Use MyFitnessPal as the app for calorie counting. It can sync with both Garmin Connect or Strava (sync with only one, I recommend Strava) so your rides get automatically recodrind in MyFitnessPal.

    If you are in to gadgets, get a FitBit activity tracker or a Garmin Vivofit so your don’t have to manually enter your activities levels (steps etc) in to MyFitnessPal (once you set up your sync).

    Also continuing with gadgets, you might want to invest in a WiFi scale from Withings or Fitbit, so you don’t keep recording your weight manual.

  15. Like some of the other reader comments I engaged the help of a nutritionist (referred by other cycling mates) to ensure my weight loss was managed while fuelling training and racing (Masters level). Over approx. 18 months I managed to lose 19kg (114kg down to 95kg) which achieved my first target weight goal and now with inclusion of a cycling coach and some racing goals a new ‘realistic’ and healthier target weight has been established. I too suffered from all the described scenarios with significant weight loss in some weeks, plateaus and gains all of which provide further motivation supported by nutritionist who predicted and explained how and why this happens, except for weeks where for my own reasons (vices) I ate more than required or to much of the wrong food groups (usually breads). Of recent with the inclusion of structured and specifically focused training I’ve continued to lose weight/ cms but have now started to see an increase in muscle mass with 1cm per month gains on thigh radius. Through my experience slow and steady rules, establishing new eating habits (salads rather than chick snitz roll from food court) and knowing number of kj’s per week to burn to maintain or lose weight has transformed me in more ways than just improved cycling.
    Interestingly people now comment on how skinny I’m getting and whether that’s healthy and those same people never said anything when I put on 50kg over an 8 year period and blew out to 134kg. Go figure.

    1. It’s a bit of a paradigm when you’re approaching awesome riding or running shape, equals lower body fat than at any other time, and they say, “you’re too skinny”. I think it’s a perception that slightly plumper looks a bit more healthy than lean/hungry, but race ready. It has something to do with the way the brain is hard wired…
      A mate of mine was at rugby weight 84kgs, but couldn’t run out of sight on a dark night. Now he’s 68kg he’s raced Ironman a couple of times and run marathons in competitive times. Yet now people recon he’s too skinny. Fk’em I say. Strip the fat and smash the hillz. FreshFruitFil

  16. I used to weigh 120kg. I now weigh 78kg. When I did 3 Peaks a few months ago, I weighed 76kg. I’ve just started dieting again for the upcoming climbing season.

    When I choose to lose weight, I avoid calorie dense foods like alcohol, sugar and fat. I avoid processed food of all kinds. I eat lots of fruit. I try to stay a little bit hungry.

    Whenever I’m struggling with my diet, I try to convince myself that it is more enjoyable to float up CRB Hill than it is to eat the delicious thing in front of me.

    Great article Matt. I’ll definitely take your suggestions on board.

  17. What were you using for estimating energy out per ride? Strava’s number , HRM conversion or Garmin’s calorie counting (which is HR based I believe)? I’ve found that a number derived from my power meter (taking raw kj of work and multiplying by 4 for total kj burned, assuming 25% efficiency – or leaving as is for the calorie count) gives a number somewhat lower than the garmin’s and strava’s estimate. Even changing it to 20% efficiency (multiply by 5) is low.

      1. These are notoriously unreliable . In fact, most fitness calorie trackers hugely overestimate the energy burned while cycling. I would take 25% off the estimated energy output from any of these calculators.

  18. I had a “reasonable” accident just as the colder months were coming on this year and have really just managed to start getting back on the bike.. along with the inactivity has come the added kgs and what I have found to be a massive lack of motivation over the colder months. Basically I have around 8 – 10 kgs to shed. Have set the target of trying to be ready for the 3 peaks and/or a 70.3 ironman (not ruling out either at this point). This article has assisted no end.. Whilst I have a HR monitor etc, I had no idea how to assess the intake of energy.. Have just down loaded the app and put in my details and it is Awesome.. Thanks so much for assisting me on my new journey!! the motivation is back.. this is so exciting!!

  19. Interesting article. Last year I had major knee surgery and some post surgery ‘lying on the couch for four weeks’ reflection led me to realising how big I had become.

    As I was always the fat kid and am still a foodie/wine lover I started by using a Sport Dietician from the Olympic Park Sports Med Centre as I wanted someone to help me stay on track with my weight while I was also going through my knee rehab (helped being in the same clinic), I found having someone there to talk to and assist to be a huge help. I also used the free Training Peaks software to track my weekly weight and daily food intake and exercise which also was a great help.

    I went from 113kg to 89kg this year and am aiming to get to 85kg when the warmer months hit and see how I feel at 85kg (may go lower). Have also found the weight is easier to keep off now I know how and what to eat and follow a basic food plan. I can say that my climbing ability has increased dramatically, I will never be a Contador as I am just too tall and broad but the loss of that much weight has increased my power to weight. Also meant a whole bunch of new cycling clothing……

    My take out points have been:
    Have a goal and if you can, share it with someone you can talk to honestly.
    Keep a food diary and be honest.
    Try to only weigh yourself 1-2 times a week and at the same day/time each time.
    Use a food to exercise app or website.
    Expect the weight loss to happen in funny ways, some good weeks and some not so good weeks.

  20. Matty – I think it would be difficult for you to effect weight change – you are already healthy, fit and have a decent metabolism. As a system, trying to interfere with that is not going to be easy.

    As an aside I have found that since I have been running I have put on some muscles mass – I am probably more cut than before, but the exercise I do not adds muscles where it was not from simply cycling.

    You are not unhealthy and therefore don’t have much to cut out. I have done some reading on nutrition and weight in terms of the ‘obesity epidemic’ and it seems that there is much more at play that simple calories in a out. An interesting article can be found here: http://aeon.co/magazine/being-human/david-berreby-obesity-era/ that describes some of the complexity of weight.

    Don’t forget as well that fluid balance is going to account for a large amount of the day to day fluctuations in weight. As a healthy young male, your large lean muscle mass means that your glycogen stores are quite large, and these are where you are storing water….

    Good read though – thanks for sharing!

  21. What a simple, clearly put – great article Matt. Well done!
    BTW, one of my brothers was and is a genuine athlete. One day he tore some knee ligaments windsurfing in large surf off Gunnamatta.
    Finally i thought I’d have my revenge – that the time off from his abundant exercise based lifestyle would turn him – to Fat! (Like his brother)
    Alas – he beat me again. Opening the door to his concerned bro – bare chested – he revealed a body with less than 6% body fat.
    How did he do it?
    Well for lunch he ate a big bag of lettuce!
    That’s right – a big bag of lettuce.
    His first run after his enforced time off was a lowly 17 kms…
    If you pack a few too many kilos – feel free to hate him – I do!

  22. really interesting Matt. i need to lose weight. at ~85kg the skinnier guys and girls just ride away from me up hills. if only i had the discipline to stay away from biscuits. mmmm, biscuits..

    1. Biscuits and cakes are/were my downfall. I just have no willpower to say no and often still find myself hitting the biscuit barrel in the evening to get my sugar fix, however I’ve found that if you earn the treats by putting in a stint on the bike, you firstly don’t put on the weight as you’re burning off enough to cancel out the bad calories, and secondly you don’t feel as guilty about it. It is hard though and the hardest part of losing weight is overcoming your inner sugar and fat addiction which is hard with the amount of crap food that surrounds us everywhere.

  23. It’s hard to lose weight, especially in winter when it’s harder to find motivation to get out in the cold and exercise. I set myself a target distance to cycle each week and use that as motivation to go out in all weather or hit the turbo if it’s too dark and I find that works as well as having a target weight in mind. It’s nice getting to the end of the day knowing you’ve banked some calorific credits and can have some treats to eat knowing you won’t put on weight. I’ve managed to drop a lot of weight this year by setting myself goals and sticking to them. Seeing my overall fitness increase, my waist size decrease and my strava times drop has made me more determined to keep at it!

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