Hey guys,
I did a little experiment this weekend.
My training plan has me do a long ride at Z2 every weekend.
I observed the well known cardiac drift in these longer (>2h) workouts. In principle, heart rate increases after some time, even though pedalling power remains constant.
My understanding is that cardiac drift might be coupled to hydration level and core temperature.
While I tried to keep hydration constant, this time (first 3h ride in a while) I experimented with carbohydrate intake to see if it might have an impact on cardia drift. Took a good portion (~50g) right in the middle of the ride (after 90min).
Efficieny factor kept dropping almost linear, but then after 140min it started to rise again.
See attacheed picture, which shows Power/HR of the 150min ride the week before and the 180min ride last weekend.
Anybody got an idea what makes Power/Hr rise again?
Position on the bike, room temperature and hydration remained the same (as far as I can tell)
Cheers!
Any caffeine intake? I often see my lunch ride (after drinking coffee during the morning) start out with HR a little higher and then tends to drop a few beats at the same steady power after about 45min. I have no idea if caffeine is the actual culprit but have just assumed it was elevating my HR until I burned it out of my system (bro science not based in actual anything).
Hmm, I definitely did not take in caffeine during the workouts.
Just judging from the daytime of the ride I guess I might have had a coffee before the ride on 8th Januray (depicted above).
Caffeine or food just before a ride gives similar results, rises your HR. Caffeine is obvious, with food look at a size of the portion before a ride (digesting huge amount of food rises HR) and type of food (hard to digest food like fats is additional work for your body resulting in higher HR)
Look at the food for 24h before the ride, maybe your glycogen storage was low resulting in riding the first 90min of the ride on fats which is harder for your body. After injecting carbohydrates your body was ready to more efficiency riding.
BTW 50g is rather small portion, for a 3h ride you should get >60-70g for every hour and some recovery food after 3rd
