Morning commute = Best effort yet, felt great. Evening commute = almost fell off bike
 

So yesterday on my ~11mi commute to work, I decided to hammer it the whole way. I typically do this morning commute in 42-46 minutes but yesterday I did it in just over 35 minutes. Average HR was 161 which is huge for me since I typically average ~135. Everything was great after, I felt really good. Tired, but good.

5:30pm rolls around and I get on the bike for the ~11mi back home and OMG I feel completely empty. My legs don't want to push, my head is a bit loopy and I'm getting cold chills in my arms even though it's 77 degrees outside. I can't get my HR over 140 on the flats no matter how much I spin. At one point on the big hill to my house (0.8mi, 7% average grade) I was worried I may actually fall over or pass out. Everything on my body felt weak and disconnected from my brain. I was zombie riding and it was the first time I seriously considered getting off the bike during a ride.

I'm pretty consistent with my rides and what I eat and yesterday was no different. I'm wondering if the morning effort is really to blame for the evening suffering or if something else may have come into play here. This is the worst I've felt on the bike since getting it 3,000 miles ago. :(

Anyone have any advice/tips for tracking down what may have caused this significantly time-delayed bonk?

BTW I rode in this morning and felt fine, but didn't push hard either (43 minutes door to door).

re: "I'm pretty consistent with my rides and what I eat"

maybe you usually skate by with your nutrition, but on this day you would have been better off with a slight adjustment. When I bike commuted I always had a late snack & coffee (over an hour before riding home), and a small box of raisins just as I left work with a little B6 & B12 for good measure. If your nutrition doesn't include the above afternoon prep then maybe it finally caught up with you. my morning rides in were always fast, sometimes I would be surprised my tires didn't burst into flames. the rides home were always modest and took significantly longer. the home ride had a elevation gain so that was part of it, but I never pushed hard going home.

You ate the same but you burned a lot more glycogen (carbs) on your ride in. It's not surprising your ride home felt different. 35 minutes isn't long but if you aren't eating enough carbs during the day it might be enough to drop you below where you should be. Try eating an extra 300 Cals of carbs next time you decide to ride hard in the morning.

Take a good pint or two of milk with you next time to drink after your hard ride in. That'll set you up.

M.

i already do this. My morning arrival snack is a pint of chocolate milk and a Clif boulder 20g protein bar. About an hour later I make a coffee with fat free half and half. :)

I can't imagine this was food related, we are talking about a 300-400 calorie effort.
Who knows, maybe you got a flu or some other little thing that makes you feel like that.

kinda think the same thing but still wondering if he consumes anything before the ride in.

you know, the best experiment would be to try it again ...

maybe he just had some bad shellfish at lunch that day?

I'd guess it's a training/metabolism issue, not fueling. I recall seeing this with tournament teams, if they have a morning and late afternoon game they suck in the late game. They've trained themselves to put out one hard effort & then go into recovery mode.

Two-a-days is something you have to train into.

Next time try and spin a cool down ride on your ride home by keeping your hr around 120bpm. This will allow for you to spin out the lactic acid in your legs, and will make you stronger for that next hard effort.

Also when you ride hard I would recommend focusing on doing intervals. Start by doing 3 mins hard 3 mins easy rather than just going all out for 30 mins. It seems like you already have a hr monitor so you should be able to track it easily. Intervals and variations of intervals is how the pros get faster.

Junk food, the lot of it. Swap chocolate for actual milk, drop the protein bar for some actual protein. You are taking in a good deal of sugar with that snack, which isn't going to help when you spend several hours sitting. And try some full fat half and half, it'll last you longer.

M.