I’ve been trying to get more educated around training and coaching recently and while I have come away with a lot of new understanding I am also generating new questions that I’d like to figure out answers for!
I’d like to ask for opinions on one question in particular: how to optimally perform zone 2 (aerobic) endurance sessions for a mostly recreational mountain biker? I’m not talking about someone who’s job it is to train, but someone who is more typically time constrained between work and and family time. Someone who has performance/competetive goals but is not a professional cyclist.
The detail of the question is really if during long (say 2hrs up to 8hrs) endurance rides aiming for zone 2, time spent above zone 2 whilst descending technical trails has a detrimental impact on the intended stress to encourage adaptation of the primarily fat burning aerobic metabolic system? It is possible for a mountain biker who enjoys the more technical riding (steep, difficult descents) to get a lot
of zone 2 time by focusing on easy efforts uphill. But it is much more difficult to not end up in higher zones when riding downhill, not due to the demands of producing traditional power through the legs for propulsion, but simply due to the demands on all muscle groups to remain atttached to and in control of the bike. This aspect of a normal mountain bike ride will result in time outside of the intended zone and probably more importantly will result in fatique of the anerobic metabolic system and depletion on muscle carbohydrate stores. But does this have a significant negative impact on the intended training stimulus of the aerobic system?
I can appreciate the additional fatique may increase recovery time and therefore delay the time that a subsequent workout may be programmed, but for a primarily time-limited non-professional athlete this may not be an issue.
Any thoughts? Anybody seen any texts elsewhere on this subject?
It probably depends how much of the total ride you end up above Z2.
I referred to a recently published paper in another thread
“A 3 minute all out test performed during an endurance-based training session did not alter metabolism or perceived exertion, nor did it affect delayed exercise capacity beyond the effect of the 3-h prolonged exercise itself. There appears to be no physiological basis for the strict exclusion of short, high-intensity bursts during endurance training.”
I would also say that keeping the pedalling time as Zone 2 work is the primary objective. But, if the work by other parts of the body needed to stay on the bike on the gnarly bits is significant, it will all add up as you describe.
I am not someone who would say “just go slower on the downhills on endurance days” but I expect there are people out there who might.
Tbh, if you manage 8h+ rides now, then you are definitely training your aerobic system plenty. Your anaerobic systems will be running on fumes far before that, anyways.
Unfortunately, I had my MTB downhill phase long before I had any data collection or HR device with me, so I can only speak from feeling; no science. But I would say that yes, sure, you might have a high HR during downhills, but I’ll wager a good part is from the “hanging on for dear life” part mostly. I.e., your whole body is in semi-isometric panic/fight/flight mode with adrenaline pumping and in ultra tunnel-vision - at least that’s how it was for me most times. I’m pretty sure you cannot even transfer the scientific results from long boring running/flat riding studies to that regime.
And even if it were the same, I wouldn’t worry - see above with the argument of 8h+ hours necessarily being mostly aerobic.
So if you are normally doing one such session per week maybe, just enjoy it for what it is. If you get in 4+ sessions per week (which I assume is not the case from the way you formulated your question), then for sure include some Z1/2 riding.
If I’d do a two week MTB holiday, riding long every day, I would certainly make sure to have easy (Z1/2) days regularly, simply to give all the “hold on for dear life” muscles a break.
Thanks for the link to that other thread! I had missed that but it contains some great information. Looks like the real answer is “it depends” but I think I’ve got useful info out of that thread to keep me on the right side of that line.
@Another_Intervaler Thanks, probably a pretty good and down to earth assessment but I can’t help thinking about the science behind it at the moment.
For a bit more context I’ll attach some stats of what I would call a “typical zone 2 mtb ride”.
That’s a 3h42 ride, with ~78% of time spent in Z1/Z2 and ~22% spent above.
Looks like 5 downhill trails ranging from 2 minutes up to 5 and a half minutes, totaling ~21 minutes of 222 minutes total (10.6%). I’m not immediately sure which side of the “it depends” line that sits but it is certainly more work than a single 3 minute interval in a long road ride.
Many things depends.
Whats your discipline within mountainbiking?
Are you covering sufficient time with intensity. How about skills and technique in training. And are you putting your self under pressure on your technique technical terrain during training? And do you train riding efficiency and active recovery?
Primarily recreational so discipline is pretty wide. Everything from big weekend “normal” mountain bike rides (not XC, think enduro without the racing), to some bike packing and multi-day trips. The occasional enduro race. The focus for developing the training is really on the endurance side - going further faster and over more days.
I’m not too worried on the skills side, this isn’t a blocker for me. On what I am trying to call a zone 2 mtb ride then my focus is smooth, efficient downhill riding rather than fast efforts down the trails. But i’m still riding very technical, steep trails on these rides.
Based on that, I would not worry too much about Z2. But I would attempt to mimic a full or part of an enduro day when it fits in. Minding the fatigue, for the following training and riding.
The most important thing to get sorted are Consistency and Volume (time).
Then for gravity. Don’t skip strength training. Preferably two times a week. But a the least once a week.
And with a balance try doing some intencity twice a week. Collecting 15-30 minutes pr session og high intencity. Including going fast down hill. But you must remember to pedal hard as well.
I have used putting intencity just before a sufficiently challenging downhill section. But to get the training from the intencity, but also to load technical abilities and riders ability of evauating the trail and lines under presure.
