adding hard cycling on slow pace days for more aerobic development?

makes no sense at all, but i want to see you do it

I forgot to mention i’m focused on the marathon

why doesn’t it make sense? I’m not doing any less running, as I can’t build up to my peak 80-90mpw any faster anyway without getting injured

i’m just adding in more effort that I don’t feel makes me feel that gassed the next day the same way a long run or long tempo puts my legs out of commission

ohmy wrote:

I forgot to mention i’m focused on the marathon

why doesn’t it make sense? I’m not doing any less running, as I can’t build up to my peak 80-90mpw any faster anyway without getting injured

i’m just adding in more effort that I don’t feel makes me feel that gassed the next day the same way a long run or long tempo puts my legs out of commission

oh that makes sense. forget what i said earlier.

full speed ahead, ahab

if you think you won't feel the effects of adding a hard ride to your day when you're already at a highish training load...just wait

add the bike ride to your hard days, not your easy days.

The obvious question is, if you add a hard effort on your recovery days, when are you going to recover?

Your legs will be destroyed.

Do an easy ride on easy run days for extra aerobic development without overstressing your legs.

As other people have said a hard cycle makes no sense. If you're going to go hard, go hard in your run. If you're not going to go hard, don't go hard.

The only way that it makes sense to do hard cycles on easy days is if you're not having any hard run days.

Hard cycling doesn't have a place in marathon training. Easy cycling would be great - I often incorporate some light spinning at 60-70% for 60-120min a few times per week.

Hard cycling is going to leave your legs too beat to run your workouts and mileage. Don't get trapped in the mentality of cross-training to be hard in order to be helpful. You're a runner, not a cross-trainer. Extra aerobic development is the best effect you could get, and you don't need hard efforts to get that. If you were injured and only cycling, it would be different.

Source: formerly fast triathlete turned fast cyclist turned runner who occasionally bikes

Cycling has no place in serious run training, and vice versa.

As an also cyclist (and former triathlete). I completely agree that cycling really has no real place in a "serious" (and we're talking breaking 3 hours, 60+ mpw) marathon training. You don't really need more endurance at that point, and really just need to time on your feet/legs to build marathon strength.

That said, I completely agree with what others have said above: replacing an easy/recovery run day with a hard bike is crazy and would be VERY counter productive.

ohmy wrote:

Would it make sense to add 30-60 min of 160+ heartrate cycling on the days when i’m slogging out recovery runs when i doubt my heart rate is going over 120? (I have no monitor but it’s def my legs preventing me from picking up the pace)

Or is this a recipe for overtraining? If it is, how do triathletes train so much?

Sounds like you're putting too much emphasis on heart rate at the expense of muscular fatigue.

ohmy wrote:when i’m slogging out recovery runs when i doubt my heart rate is going over 120? (I have no monitor but it’s def my legs preventing me from picking up the pace)

What makes you think recovery days are for additional aerobic development?

ohmy wrote:

Would it make sense to add 30-60 min of 160+ heartrate cycling on the days when i’m slogging out recovery runs when i doubt my heart rate is going over 120? (I have no monitor but it’s def my legs preventing me from picking up the pace)

Or is this a recipe for overtraining? If it is, how do triathletes train so much?

Horrible idea. When are you gonna recover? Did it occur to you you are venturing into excessive muscle breakdown and fatigue that will make you crash faster than the Concorde on race day?

Ultimately:

It’s your body bro, you are free to destroy it as you wish.

ohmy wrote:

Would it make sense to add 30-60 min of 160+ heartrate cycling on the days when i’m slogging out recovery runs when i doubt my heart rate is going over 120? (I have no monitor but it’s def my legs preventing me from picking up the pace)

Or is this a recipe for overtraining? If it is, how do triathletes train so much?

First off - For the love of god NO.

Second off - get a HRM for finding out if your recovery runs are actually recovery or if they are actually hurting. Many people think their RPE is 2 - 3 and reality is their HR is 75%+

Third: via training smart - I.e. hard days, easy days etc. Currently, I am training for a race in late August (COVID pushed it back from May). I have nine - fourteen sessions per week with on days, off days, lots of doubles, and some long singles. It helps that swimming is mostly upper body with literally zero impact. I own and run my own business, with COVID training time has gone down as we've had to scramble to make ends meet.

Example week: 3x swim, 4x run, 4x cycle. I enjoy cycling the most and swimming the least.

Time breakdown of a typical 70.3 or 140.6 race is 50% cycling, 33% running 17% swim.

ITU or olympic distances put more emphasis on the swim.

Monday: easy recovery swim + stroke drills - 1HR, RPE 2 - 3. Expected TSS less than 50.

Tuesday: AM Run Intervals (5mi), PM Bike Intervals (1hr)

Wednesday: AM: Swim intervals (1hr). PM: 7mi with 20 minute hard tempo run (1hr)

Thursday: AM Long Swim Steady state (1hr). PM: Threshold bike @FTP (1-1.5hr)

Friday: AM - Brick Bike 4x FTP Ramps + 5k Run (1.5 hr). PM Hypervolt/Foam Roll recovery

Saturday: AM Long Run: 14 - 16 miles. (2hr) PM, NormaTec recovery

Sunday: AM Long ride, 70 - 100 miles (3 - 5hr) depending on week, T2 Practice + 1Mi Run at 'thon pace. PM: NormaTec/recovery.

Monday is a general recovery day + drill day for swimming as a lot of pace and time is found by perfecting technique. About an hour in the water with 1700 - 2500 meters, depending on number of drills vs easy swim time.

Tuesday is a hard interval day coming off of the recovery day. I put the run in the morning for several reasons. Biggest is running is an open chain movement while cycling is close chained.

Wednesday is another hard day, but not as hard as Tuesday. with swim intervals (6x400m, 3x1000 etc) and a tempo run with some easy miles either side of it

Thursday starts with a one hour medium/hard swim to flush some of the junk from the last two days and prep for a 20 - 30 mile hard ride later in the evening.

Friday is a big day - bricks are used to get used to the feeling of coming off the bike and going straight into the run. It's nicknamed a brick because thats how your legs feel.

Saturday - single session as a long run

Sunday - single session as a long ride and T2 practice.

I am an amateur with emphasis in cycling, a professional (Lucy Charles used as example) has 5 bikes, 3 - 4 runs, and 4 - 5 swims per week, and 1 - 2 S&C sessions per week. Her training tops out around 25 - 30 hours. In general, keep your hard days hard and your easy days easy. Recovery is where progress happens.

Training = Work + Recovery, or as Mark Twight says don't do the work if you don't have the balls to recover.