Shoe Review: Pearl Izumi isoTransition (Women's)

I've posted 2 shoe reviews for this blog: the Women's Nike Lunar Glide +2 and the Women's Asics GT-2160.  I was not asked to review them as an official tester. I bought the shoes for myself and shared my experiences, opinions and advice. When I raised my virtual hand to be a tester for Pearl Izumi (by way of being a Dailymile team member), I wasn't exactly sure what to expect. I wasn't familiar with hadn't even heard of Pearl Izumi prior to volunteering to be a tester. While some of our DM team members were sent the Pearl Izumi Streak II, a few of us (myself included) were sent the isoTransition, marketed for triathletes, due to shoe size availability for testing purposes. Oh great. Not only am I already questioning whether I'm even qualified to be a tester, now I'm asking myself  "Who the heck is going to care what a non-triathlete thinks of a triathlete shoe? Maybe I should back out". You know who cares now? Me. Because I love these shoes.

I was so excited to get my first pair of official tester shoes by the time they arrived. Other team members had already received their Streak's and were running in them! We all had an agreement not to discuss anything about the shoes until the Dailymile Team Review had been posted on both models so as to not bias each other. I also purposely did not do ANY research on the shoe or the company. In fact, I did not even go to the PI website, talk to other runners or look for retail prices until after the trial period was over. This is absolutely the least biased review I could possibly publish on this shoe.

This is what I typed out within 30 minutes of having these hot little shoes in my hands:

1. Couldn't even wait to get home to open the box. 
2. Ripping box open at a stoplight so I could see them (picked up at UPS just 2.5 miles from my house)
3. Ran in the house and upstairs to show the hubby
4. Threw one to (at?) him and pulled my shoes off so I could try out the Izumi's
5. They gave my feet a hug - slightly concerned I should have asked for an 8.5 when I stood up [I didn't know I wasn't supposed to wear socks with them until my 2nd time wearing them]
6. Love the laces - easy to use/figure out. SO nice not to have worry about laces.
7. Rolled up my jeans and jumped on the TM. Ran about 0.15 miles while gushing to my husband about how great and different they felt from my other shoes. 
8. Flatter than Lunar Glides in the heel and forefoot
9. Can DEFINITELY tell these are a flat shoe (heel toe drop is low)
10. Flexible forefoot allows for toe splaying; ease of toe-off due to design

With some concern around injuring myself before Grandma's marathon, I used the same transition plan with the isoTransitions as I did with the Lunar Glide +2. Baby steps at first - using them only 1 day a week. At the time I started bringing these shoes into rotation, I still had two 20+ mile LSDs and several 40+ mile weeks ahead of me. I will admit to running farther and longer than I did intitially with the LG +2. I felt safer taking bigger steps with the PIs since I was already adapted to the LG's. It wasn't as if I was trying move from my current LSD shoe (Asics 2160) down to the Isotransitions directly. I am more convinced than ever of the importance of maintaining discipline in the frequency of use of these shoes if you are not properly adapted. The risk of over-stressing your Achilles tendon, ankles, knees and hips is very high otherwise. Speeding up the transition could actually set you back in your training schedule so take it slow!

Testing Notes!

Day 1:  7 miles

I had some tempo work to do on this day. While I did have some numbness in my left toes, I found after a couple of weeks of use that this was probably due to a need for my feet to adapt to the shoes and vice versa. The seamless interior was new to me and it felt great! I couldn't believe that a shoe could conform so well to my foot. And with the loop in the back, it's an easy slip on/slip off shoe. I had more control of my feet and thus my legs in general. The shoes are so lightweight, I almost forgot they were even there.

About an hour after I'd finished this first longer distance test run (the day after the shoes were delivered), I felt the urge to scribble down some reflection thoughts that were running through my head. I grabbed the closest piece of scratch paper and pen, resulting in the following:

"I had this moment where I felt like my body just clicked into place. My hips narrowed, my legs aligned perfectly almost like they were being locked into the most anatomically efficient position. It was the closest thing to having an out of body experience I've had. Thinking "This is what great form feels like! This is what I've been trying to find for years!". I tried not to stay too aware of it for fear that focusing on it might somehow chase it away. I can't remember how long it lasted; came and went a couple of times. Definitely felt like I was running faster and more efficiently (more work with less effort - especially with the increase in foot turnover)."

Day 2:  6.75 miles 

I've been having L ITB pain since the mud run [I ran the Merrell Down and Dirty Mud Run 10K the day before my first 7-miler in these shoes]. Right ITB soreness is mostly gone. Took about 2 miles to feel loosened up. Had some weird knee pain on both sides but it dissolved. Couldn't run faster than 6.5 mph using 4:30 run/0:30 walk intervals. [This is my normal run/walk ratio for weekday training runs (with the exception of mile repeats) and for distances less than 15 miles.]

Got into a great stride spot again today. Is this in my head? Loosened up the laces and didn't have any toe-numbing issues. L shoe still feels a little small. Ran with no socks - shoes are much more comfortable that way (even though they were comfortable with socks). Love feeling the belt under my feet with minimal padding. 

Tech specs: (Zappos)

Ortholite® sockline

Seamless interior (no socks!!)

Heel/Toe offset: 19.0mm/10.0mm

Drainage holes in the midsole allow water and sweat to escape

Weight : 7 oz

Inner sole is mesh so water and sweat drain out

Ortholite liner with drainage holes

 I do recommend these shoes for:

1. Speedwork, tempo and steady state short-to-medium distances (5K, 10K, 15K, 10 mile races)
2. Midfoot/forefoot plantars
3. Medium arches
4. Runners looking to transition to minimalist shoes
5. Triathletes looking for a quick swim-to-bike and bike-to-road running transition shoe
6. Neutral foot type

I do not recommend these shoes for:

1. Heel strikers **Please read this EXCELLENT article on The barefoot running debate: Born to run, shoes & injury: the latest thinking just posted today (5/6/11) by Ross Tucker, Ph.D. 
2. Runners who need stability
3. Runners who need extra cushioning
4. Long distances UNLESS you are already running LSDs in minimalist shoes

Differences between the isoTransition and the Streak II
The loop in the back for easy slip on/slip off (shoes are intended for use when cycling as long as you don't have clip pedals), drainage holes, 360 laces in the Streak II to conform to foot as the bungie laces do. I ran through wet grass this past weekend in the isoTransitions. Both my feet and the shoes felt dry in less than 10 minutes. No blisters, no hot spots.

PI Streak II

PI markets both shoe models as Triathlete shoes, however, only the Streak II is marketed as a road shoe.  I can see the difference in the rubber at the toe of the shoe [the Streak II is a little thicker]. Interestingly, PI makes no mention of the distance you can expect to run in the isoTransitions but they do specifically state the Streak II can be worn for marathons. I suspect this is due to a slightly more padded Ortholite liner. 


My preference is the isoTransition because of the features that are not included in the Streak II. Then again, I don't plan on running a marathon in this type of shoe for at least 6-8 months. I haven't even run a marathon in the Lunar Glide +2 yet. Not that I think that is a prerequisite, but I want to make absolutely certain I'm not rushing into distances my legs aren't ready for yet.

In all, I've put about 60-65 miles on the isoTransitions. While I did have to scale back to using them 1 day a week after an over-zealous couple of weeks attempting to run in them twice a week, I will continue to use these for speedwork and shorter distances. If I find I need a little extra padding in the forefoot for LSDs in the future - you can be sure I'll be back for the Streak II or will it be III by then? ;-)

Looking for more reviews? Here are our Dailymile Team Reviews on the Men's and Women's PI Streak II and the Women's isoTransition.

At $110 retail, it is a pricey shoe. The cheapest I've been able to find them online is at Kelly's Running Warehouse ($98 for the isoTransition and $81 for the Streak II).


Happy Speed Training!!