I'm very late this month with the monthly training challenge, but the reasoning was to give you all more time completing the May Challenge. Since that challenge built up your endurance, extending it a few weeks will work out well for your July and August events.
But now it is time to ramp up some intensity!
My favorite workouts of all are the sprint workouts. If you have a Power Meter try and increase you highest 5 second sprint by 20% of your current highest Wattage. So if you are hitting 800 watts on you 5 second sprint I want you to push it up to 960 watts as an example. I know, I know, you'll have to do some math each week with this challenge, but you'll get better at both your sprints and your math by the end of the challenge! So each week until the July Challenge is out add 5 sprints to 2 of your weekly rides. Don't add them in back-to-back rides but spread them out over the week. The other part of this challenge is to increase the top end 5 second sprint by 20% each week!
So using the example above:
Week 1: goal 960 watts
Week 2: goal 1152 watts
Week 3: goal 1382 watts
If you don't have a power meter then use speed. If you can hold 25 mph for 5 seconds currently.
Week 1: goal 29 mph
Week 2: goal 34 mph
Week 3: goal 40 mph
If you push yourself a little bit you will be surprised how little training stress is needed to see big gains. As always if you are feeling particularly worn out on a day when you are supposed to push the intensity, take the ride down a notch and allow your body to recover more fully before pushing the intensity again. Insurance requires me to remind you to always check with your doctor before trying this or any other athletic training plan.
Good luck and Ride On!