What's it like to gain 20 W and lose 2 kg?

Recently, I put a message up on Facebook (here), asking if riders were interested in finding 20 W and losing some weight. The response was huge, and we found the riders I was looking for.

However, many people wanted to know what 20 W and losing some weight would equate to for their cycling performance, so, looking at six imaginary scenarios, I decided that I would crunch some numbers to show you.

What sort of rider?

Our riders consist of a non-racing sportive rider, two racers who compete in time trials over 25 miles (42ish km for us metric people!), and three riders who decide to go and ride up the full length of Alpe d’Huez (so that they’re timed over the same section of road as the pro riders). I chose those scenarios – to illustrate the changes because many riders who race - time trial (and those who don’t can still understand the gains), some people don’t race – but want to be faster at a sportive, and of course many of us want to emulate our heroes and have a go at perhaps the most famous of climbs to see where we’d come if we were in the Tour de France!

Cycling up Alpe d'Huez

Then for the Alpe riders, I thought I’d ascertain the difference of losing 2 kg in weight (which to be honest is a modest amount for those we work with who come to us who want to lose weight as their primary goal), and then once they’ve lost the 2kg, what adding 20 W on would do.

For the sportive, and TTers, I kept their weight constant, and just slapped on 20 W. Of course, for many at the lower power end we find more than 20 W, and even at the very top end of the sport we’ve found 20 W for these riders.

And, of course, before anyone writes in to chastise me (!), I should really say they’re losing 2kg in mass (not weight)!!

So, first of all, how easy is it to gain 20 W? It sounds like a relatively small number. Without doubt, adding 20 W is somewhat difficult. For e.g. if you race, you may find that your FTP out of season versus in season drops by ~25 W (or 10% of your FTP). If you race, you’ll know, that out of season, feeling rubbish in the winter, will mean that at ~25 W less you’ll get dropped in a road race. Gain that amount and you’ll be doing well.

Furthermore, we know that people who cheat and take EPO (I’m not for one-second suggesting anyone takes it; as we have a strong anti-doping ethic at RST Sport) can gain someone between 5 and 10% in power output (so 12.5 W to 25 W). So, for clarity 20 W looks small, but for most riders it’s a significant change to their fitness. Of course though, some riders gain much more than this (e.g. with my own riding, just riding around and not training seriously to training seriously gains me about 40 W, and I’m still trying to add more!).

To keep things simple in the weight loss section, I thought we’d just have the Alpe riders lose 2kg. For some this may be relatively easy (and they may need to lose more), while for others it could be somewhat difficult. Again, using my own data, a couple years ago, I went from not worrying too much about my diet (71kg) down to 65/66 kg in summer and about 2 kg more in winter. I’ve absolutely no doubt that if I was a pro cyclist I could probably lose another 2 kg, but I’m not a pro cyclist (I’m way too old!) and my better half might bin me for looking like a skeleton! ;-)

Here comes the science!

Scenario 1 – Non racing sportive rider

60 mile (96.6 km) sportive ride, ridden at 16 mph (25.75 km/hr), on a flat route. Rider and bike total mass are 85 kg. This requires about 125 W (obviously this will depend on your aerodynamic drag), and would take 3hours45mins to complete, which is a good effort for a non-racer. Adding on 20 W (now 145 W) would up your speed to 17.27 mph (27.79 km/hr) and reduce your time down to 3hours 28. Saving of ~17 minutes!


Scenario 2 – Club racer

25 mile TT (40.23 km) ridden at 25 mph (40.23 km/hr) takes exactly 1 hour. This requires approximately 268 W and adding 20 W is 288 W. This would increase your speed to 25.658 mph (41.29 km/hr), taking 1 minute and 32 seconds off your time.


Scenario 3 – Excellent club racer

25 mile TT at 27.778 mph (44.7 km.hr) takes exactly 54minutes, and about 311 W. Adding on 20 W (331 W) increases the speed to 28.41 mph (45.72 km/hr) and takes the time down to 52:48 (saving 1 minute 12 secs).


These are all highly significant improvements.


Scenario 4 – 80 kg rider with a total weight of 90 kg taking 90-mins to climb the Alpe. This requires about 191 W or 2.38 W/kg


Losing 2 kg, while maintaining the same power takes 2-minutes of the time and puts your W/kg at 2.44.


Scenario 5- 75 kg rider with a total weight of 85 kg taking 75 mins to climb the Alpe, requires about 220 W. (2.93 W/kg). Knocking off 2 kg at the same power reduces the times to 73.5 mins (1:30 saving) and increasing power to mass ratio to 3.01 W/kg


Scenario 6 – 75 kg rider with a total weight of 85 kg taking 59 mins climb the Alpe requires about 285 W (3.8 W/kg). Losing 2 kg and staying at 285 W takes 60-secs off the time (58mins) and put the W/kg at 3.9.


If we now combine scenario 4 to 6 (2 kg weight loss) each with a 20 W increase in power we have scenarios 7 to 9.


Scenario 7 is now 80mins and 12-secs which is a saving of almost 10-mins and is 2.71 W/kg

Scenario 8 is now 67:30 and 3.27 W/kg saving 7 and a half minutes

Scenario 9 is now 54:30 and 4.178 W/kg saving 4 and a half minutes.

Again, these are all significant savings/speed increases, which are well worth training for so that you can achieve them.


How to lose weight and gain power?

So, how do we lose 2kg, and/or gain 20 W? Most people can make changes to their diet, which will help them lose weight. There’s a myriad of different diet styles, many of which will help you lose weight. There’s a few that I favour (e.g. Mediterranean Diet, vegetarianism, moderate carbohydrate, etc) and some tactics to help (e.g. occasional fasted riding). If you want to lose 2kg or more we can help you to achieve this in a healthy and performance enhancing way – our Silver level and above coaching will discuss dietary advice along with cycling or triathlon coaching. However, to keep things easy there’s a few maxims I like to use
1) You most likely need to eat less than you think do

2) Crap food is crap food, and even though it may not make a difference to your weight loss as an equal amount (calorie wise) of quality food, putting crap in your tank just isn’t the best way forward for performance
3) There is no magic diet that makes you lose weight

How do you gain 20 W? As with weight loss, it will depend on where you are: If your fitness is low, gaining 20 W is easier than if you’re a World Tour Pro – the fitter you are the more specific your training will need to be to raise your game.  Most likely though, adding 20 W will consist of adding in some intensity (intervals of some sort) and perhaps doing more work. It’s difficult to give a general idea, because it really does depend on many issues (e.g., your current fitness level, your trainability, your time availability, your mental tenacity/psychology, your goals, etc).

If you’d like to lose weight and/or gain some power then give me a shout on ric@cyclecoach.com and we’ll help you smash things if you’re serious about your cycling or triathlon performance.